JP3402597B2 - Actuator device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator device, and is suitable for application to, for example, an AC (Alternating Current) servo motor.

[0002]

2. Description of the Related Art Conventionally, in an AC servomotor, a rotor rotatably supported, a plurality of stator cores fixedly arranged at a predetermined interval so as to surround the rotor, and each stator core are respectively wound. And a stator including a plurality of coils are integrally housed inside the motor case.

Further, in the AC servo motor, normally,
A rotational position sensor for detecting the rotational position of the rotor shaft is provided on the side opposite to the rotational torque output of the rotor shaft (hereinafter referred to as the rotor shaft) outside the motor case.

In an actuator system using such an AC servo motor, a controller is provided separately from the AC servo motor, and the controller uses the sensor signal output from the rotational position sensor of the AC servo motor. Various arithmetic processes for obtaining a desired rotation output are executed, and a drive current based on the arithmetic result is supplied from the controller to the AC servo motor to control the rotation of the AC servo motor.

[0005]

However, in such an actuator system, a cable for connecting the controller and the AC servomotor is composed of three cables for rotational driving (for coils) and four to twelve cables for rotational position sensors. 7
There was a problem that a relatively thick wire rod from 15 to 15 was required, and that this wire rod also had a special cable specification in consideration of the influence of noise or the like and measures against disconnection due to mechanical vibration.

Further, in such an actuator system, in addition to the wiring between the AC servo motor and the controller, communication wiring between the controller and a higher-order controller is required. Therefore, the wiring of the entire system is required. Since there are many cases, there is a problem that the structure is complicated and the assemblability is poor.

Further, in such an actuator system, since the rotor of the AC servo motor and the rotational position sensor are structurally arranged at a distant position, the AC servo is required to perform positioning with high accuracy and high speed. Since the rotor shaft of the motor needs to be thick and the structural material of the connecting portion must have high mechanical rigidity, there is a problem that the system as a whole becomes heavy and large.

Further, in such an actuator system, since the rotational position sensor is large and heavy, a large AC servomotor is required in order to perform high-speed positioning, and the bearing thereof has high rigidity. There was a problem that something was needed.

Further, in such an actuator system, since the AC servo motor generates heat during driving, the maximum value of the drive current given to the AC servo motor is limited, but in reality, the safety factor with respect to the maximum drive current value. However, there is a problem in that the output torque is limited because only a low current including the current can be applied to the AC servomotor.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose an actuator device that simplifies the structure of an actuator system and can easily reduce the size while improving the performance.

[0011]

In order to solve the above problems, in the present invention, a rotor rotatably supported,
In an actuator device in which a stator that generates torque in a rotor is housed in a housing, a drive circuit that supplies a drive current to the stator and a control gain that determines a response characteristic given in advance to a specified rotation angle or rotation speed. The housing is provided with an arithmetic means that holds the parameter and calculates the current command value to be given to the drive circuit using the control gain parameter. As a result, in this actuator device, the arithmetic means for controlling the actuator device can be integrated.

Further, according to the present invention, a rotor rotatably supported, a stator for generating torque in the rotor, a housing for accommodating the rotor and the stator, and a torque generated in the rotor are amplified and passed through an output shaft. In an actuator device having a torque amplifying means for outputting as a drive signal, a drive circuit provided in a housing for supplying a drive current to a stator and a response characteristic given in advance in a housing for a specified rotation angle or rotation speed are provided. A calculation unit that holds the control gain parameter to be determined and calculates a current command value to be given to the drive circuit using the control gain parameter, and a rotation angle detection unit that is provided in the torque amplification unit and that detects the rotation angle of the output shaft. Is provided, and the calculation means uses the mathematical model of the torque amplification means given in advance to detect the rotation angle. And of calculating the estimated value of the external force given from the detection result to the output shaft of the torque amplifying means, and to determine the current command value in accordance with the estimation result. As a result, in this actuator device, the arithmetic means for controlling the actuator device can be integrated.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Configuration of AC Servo Motor According to the Present Embodiment In FIG. 1, reference numeral 1 indicates an AC according to the present embodiment as a whole.
A servo motor is shown, and includes a motor unit 2 that generates a rotation torque, and a torque amplification unit 3 that amplifies and outputs the rotation torque generated in the motor unit 2.

In the motor section 2, a rotor shaft 6 rotatably supported by rotary bearings 5A and 5B is provided inside a motor case 4 made of a conductive material such as metal, and a rotor base 7 is attached to the rotor shaft 6. Further, as shown in FIGS. 2B and 2C, a rotor 9 is formed by coaxially integrating a rotor magnet 8 which is a ring-shaped permanent magnet magnetized with four poles.

Inside the motor case 4, as shown in FIG. 3 and FIG.
The stator cores 10A to 10F are fixed at equal intervals (60 [°] intervals), and each of the stator cores 10A to 10F is fixed.
The coils 11 (11A to 11F) are formed by winding the respective (10A to 10F).

As a result, in the motor unit 2, 180
[°] Two opposing coils 11 (11A and 11D,
11B and 11E, 11C and 11F) (there are three sets in total) as U-phase, V-phase and W-phase, respectively.
120 [°] for each phase 11, V phase and W phase coil 11
By applying drive currents whose phases are shifted from each other to generate a magnetic field having a strength corresponding to the current value of the drive current in each coil 11, a rotational torque having a magnitude corresponding to the current value of the drive current is generated via the rotor 9. It is designed to be able to generate.

On the other hand, the torque amplification section 3 has a gear case 12 detachably fixed to the tip of the motor case 4, as shown in FIGS. 1 and 5A to 5C.
Inside the gear case 12, an annular internal gear 13 fixed to the inner surface of the gear case 12, a sun gear 14 fixed to the tip of the rotor shaft 6, and an internal gear 13
And the first arranged at 120 [°] intervals between the sun gear 14
~ A planetary gear mechanism 16 including third planetary gears 15A to 15C is provided.

The shafts 17A to 17C of the first to third planetary gears 15A to 15C of the planetary gear mechanism 16 are rotatably arranged at the tip of the gear case 12, respectively.
It is fixed at 8.

As a result, in the torque amplifying section 3, the rotational torque applied from the motor section 2 via the rotor shaft 6 is amplified via the planetary gear mechanism 16 to output the output shaft 1.
8 and can be output to the outside through the output shaft 18.

In addition, the torque amplifying portion 3 has an annular resin magnet 19 fixed to the output shaft 18, and first and second resin magnets 19 fixed to the outer peripheral surface of the gear case 12 so as to face the outer peripheral surface of the resin magnet 19. A one-rotation absolute angle sensor 21 including a second magnetic sensor (hereinafter referred to as a Hall element) 20A and 20B is provided.

In this case, the resin magnet 19 is shown in FIG.
As shown in (A), the magnetic flux density φ (θ
g) is magnetized so that it changes as shown in Fig. 6, and
The first and second Hall elements 20A and 20B are shown in FIG.
Gear case 1 with a phase difference of 90 ° as in (B)
It is fixed to the outer peripheral surface of 2.

As a result, in the one-rotation absolute angle sensor 21, the rotational displacement of the output shaft 18 is caused by the magnetic flux density φ (at the position where the first and second Hall elements 20A and 20B are arranged due to the rotation of the output shaft 18. θg) as the change, and the detection result is detected by the first and second Hall elements 20A, 20
B to sin (θ
g) and cos (θg), the first and second single rotation absolute angle sensor signals S1A and S1B having a waveform can be output.

In addition to this structure, this AC servomotor 1
In this case, the rotor shaft magnetic pole angle sensor 2 for detecting the magnetic pole angle of the rotor shaft 6 is provided inside the motor case 4 of the motor unit 2.
2, a control board 23 that controls a rotation angle, a rotation speed, a rotation torque, etc. of the output shaft 6 based on a command from an external host controller (not shown), and a motor unit under the control of the control board 23. A power board 24 for supplying a drive current to each of the coils 11 is housed.

In this case, the rotor shaft magnetic pole angle sensor 22 is
Resin magnet 25 fixed to the front end surface of rotor base 7 of rotor 9 and first to fourth magnetic sensors (hereinafter referred to as Hall elements) 26A to 26D mounted on control board 23.
It is formed from and. And the resin magnet 25 is
As shown in FIGS. 2B and 2C, the same four magnets as the rotor magnet 8 of the rotor 9 are magnetized and fixed to the rotor base 7 in the same phase as the rotor magnet 8.

The first to fourth Hall elements 26A to 26
8D, the first and second Hall elements 26A and 26B are arranged on the concentric circle with the rotor shaft 6 as shown in FIG. 8B.
[°] Opposing, and the third and fourth Hall elements 26C,
26D is the first and second Hall elements 26A, 26
It is mounted on the control board 23 so as to be located at a position shifted by 45 [°] in the same direction as B.

As a result, this rotor shaft rotation angle sensor 2
2, the magnetic pole angle of the rotor shaft 6 is detected as a change in the magnetic flux density at the positions where the first to fourth Hall elements 26A to 26D are arranged due to the rotation of the resin magnet 25 rotating integrally with the roller shaft 6. It is designed to be able to do.

The magnetic pole angle of the rotor shaft 6 is defined as the angle obtained by multiplying the mechanical rotation angle of the rotor shaft 6 by half the number of magnetic poles of the rotor magnet 8 (see equation (2)). In this embodiment, since the rotor magnet 8 is magnetized to have four poles, the magnetic angle takes a value in the range of 0 to 2π.

On the other hand, the control board 23 has a structure shown in FIG. 1, FIG.
As shown in FIGS. 8 and 9, the one-chip microcomputer 27 and the crystal oscillator 28 for clock generation are mounted on one side of the annular printed wiring board, and the above-described rotor shaft rotation is mounted on the other side. First of the angle sensor 22
The fourth hall elements 26A to 26D and the temperature sensor 29 that detects the temperature of the resin magnet 25 are mounted.

In the control board 23, as shown in FIG.
As described above, the outputs of the first and second Hall elements 26A and 26B and the outputs of the third and fourth Hall elements 26C and 26D in the rotor shaft magnetic pole angle sensor 22 are respectively set to the first output.
And the first and second rotor shaft magnetic pole angle sensor signals S2A and S2 by adding through the second and second subtraction circuits 30A and 30B.
B is taken into the one-chip microcomputer 27, and the one-rotation absolute angle sensor 21 (see FIGS. 1 and 5).
(C)) via the cable 31 (FIG. 1), the first and second one-turn absolute angle sensor signals S1A, S1
B can be incorporated into the one-chip microcomputer 27.

In the control board 23, two power supply lines, one general-purpose parallel communication line, and two RSs.
-232C serial communication line and three synchronous serial communication lines are connected to the host controller through a second cable 32 (Fig. 1), and thus the one-chip microcomputer 27 connects the second cable 3
A drive voltage can be input via 2 and communication with a host controller is possible.

Then, the one-chip microcomputer 27
Is a designated value of a rotation angle, a rotation speed or a rotation torque of the output shaft 18 (FIG. 1) given from the host controller via the second cable 32 (hereinafter, these are designated rotation angle, designated rotation speed and designation, respectively). (Turning torque)
And the first and second one-turn absolute angle sensor signals S1A,
S1B, first and second rotor shaft magnetic pole angle sensor signals S2A and S2B, and first to third drive current detection signals S3A to S3C supplied from the power board 24 as described later.
The current values of the drive currents to be applied to the U-phase, V-phase, and W-phase coils 11 (hereinafter, referred to as first to third current command values, respectively) are calculated based on The calculated first to third current command values are applied to the third cable 3
3 to the power board 24.

In the power board 24, as shown in FIGS.
As shown in (B) and (C), a plurality of power transistor chips 35 forming a coil drive block 34 shown in FIG. 10 are mounted on one surface side of an annular printed wiring board. There is.

The coil drive block 34 is based on the first to third current command values given from the one-chip microcomputer 27 of the control board 23, and each of the U-phase, V-phase and W-phase of the motor unit 2 is controlled. The rotor 9 of the motor unit 2 is rotationally driven by applying a drive current having a corresponding current value to the coil 11.

At this time, the coil drive block 34 detects the current values of the drive currents respectively applied to the U-phase, V-phase, and W-phase coils 11 at this time, and the detection results are detected as the first to third values. Drive current detection signals S3A to S3C of the control board 23 via the third cable 33 (FIG. 1).
Send to.

In this way, in the AC servomotor 1, the one-chip microcomputer 27 of the control board 23 is provided.
The motor circuit 2 is driven by the control circuit including the coil drive block 34 of the power board 24 according to the designated rotation angle, the designated rotation speed, or the designated rotation torque given from the host controller.

(2) One-chip microcomputer 27
Configuration of Coil Drive Block 34 Here, the one-chip microcomputer 27, as shown in FIG. 11, includes an arithmetic processing block 40, a register 41, a rotor shaft rotation angle detection processing block 42, and a torque-3 phase current signal conversion processing block 43. , Current control processing block 4
4 and first to fourth analog / digital conversion circuits 45
It is composed of 48.

Then, the one-chip microcomputer 27
Then, one rotation absolute angle sensor 21 (FIG. 1, FIG. 5 (C))
The first and second one-rotation absolute angle sensor signals S1A and S1B supplied from the digital converter are digitally converted by the third analog / digital conversion circuit 47, and the obtained first and second one-rotation absolute angle sensor data D1A. , D1B are stored in the register 41.

In the one-chip microcomputer 27, the first and second rotor shaft magnetic pole angle sensors based on the output of the rotor shaft magnetic pole angle sensor 22 provided from the first and second subtraction circuits 30A and 30B (FIG. 9). Signal S2A,
The second analog / digital conversion circuit 46 digitally converts S2B, and the obtained first and second rotor shaft magnetic pole angle sensor data D2A and D2B are input to the rotor shaft rotation angle detection processing block 42.

Rotor shaft rotation angle detection processing block 42
Is the magnetic pole rotation angle of the rotor shaft 6 (hereinafter referred to as the rotor shaft magnetic pole rotation angle) Pml based on the supplied first and second rotor shaft magnetic pole angle sensor data D2A, D2B.
And the magnetic pole angle θp are detected, the rotor shaft rotation angle Pml is stored in the register 41, and the magnetic pole angle θp is calculated as the torque −
It is sent to the three-phase current signal conversion processing block 43.

It should be noted that the magnetic pole rotation angle of the rotor shaft 6 (rotor shaft magnetic pole rotation angle Pml) is the first value as the rotor shaft 6 rotates.
~ It is defined as an angle in which one cycle (0 to 2π) is a magnetic pole change due to a pair of adjacent N and S poles of the resin magnet 25 detected by the fourth Hall elements 26A to 26D.
In this embodiment, since the resin magnet 25 is magnetized to have four poles, the rotor shaft magnetic pole rotation angle Pml takes a value in the range of 0 to 4π.

Then, the arithmetic processing block 40 stores the first and second one-turn absolute rotation angle sensor data D1A and D1B and the rotor shaft magnetic pole rotation angle Pml thus stored in the register 41, and the designation given from the host controller. Based on the rotation angle, the designated rotation speed, or the designated rotation torque, a target rotation torque (hereinafter, referred to as target rotation torque) T0 is calculated, and the calculation result is stored in the register 41.

The target torque T0 stored in the register 41 is read by the torque-3 phase current signal conversion processing block 43. Then, the torque-three-phase current signal conversion processing block 43 receives the target torque T0 and the rotor shaft 6 supplied from the rotor shaft rotation angle detection processing block 42.
U of the motor unit 2 based on the magnetic pole angle θp of
The first to third current command values U representing the current values of the drive currents to be applied to the coils 11 of the V-phase, V-phase, and W-phase, respectively.
r, Vr, and Wr are calculated, respectively, and sent to the current control processing block 44.

At this time, the current control processing block 44 digitally converts the first to third drive current detection signals S3A to S3C supplied from the power board 24 from the first analog / digital conversion circuit 45. Obtained first to third drive current detection data D3A, D3B
Is given.

Thus, the current control processing block 44 uses the first to third current command values Ur, Vr, Wr and the first current command values Ur, Vr, Wr.
-Based on the third drive current detection data D3A, D3B, predetermined signal processing including compensation processing for voltage fluctuation is applied to the first to third current command values Ur, Vr, Wr, and then this is applied. PWM (Pulse Width Modulation) modulation,
The obtained first to third PWM signals S4A to S4C
This is sent to the coil drive block 34 of the power board 24 via the cable 33 of FIG.

The third cable 33 has first to third cables.
Two lines are provided for each of the PWM signals S4A to S4C. The current control processing block 44
1 to 1 when driving the output shaft 18 (FIG. 1) in the normal direction.
The third PWM signals S4A to S4C are respectively applied to one of the first PWM signals.
To the coil drive block 34 of the power board 24 through the line of the first to third PWM signals S4A.
Signals of logic "0" level in S4 to S4C (hereinafter, referred to as first to third reference signals) S5A to S5C are sent to the coil drive block 34 of the power board 24 through the respective second lines of the other side. Send out.

Further, the current control processing block 44, when the output shaft 18 is driven in reverse, drives the first to third PWM signals S.
4A to S4C are sent to the coil drive block 34 of the power board 24 via the second lines, respectively, and the first to third reference signals S5A to S5C are sent to the power board 24 via the first lines, respectively. Coil drive block 3
Send to 4.

The coil drive block 34 is shown in FIG.
As shown in 0, four amplifiers 50A to 50 are provided corresponding to the U-phase, V-phase, and W-phase coils 11, respectively.
First to third gate drive circuits 51A to 51C having the same configuration as C, two PNP type transistors TR1 and TR2, and two NPN type transistors TR respectively.
3 and TR4 having the same configuration as the first to third inverter circuits 52A to 52C.

In the coil drive block 34,
The U-phase, V-phase, and W-phase first lines respectively correspond to the corresponding first to third gate drive circuits 51A to 51C through the corresponding first and third amplifiers 50A and 50C, respectively. The base and the first N of the second PNP transistor TR2 of the third inverter circuits 52A to 52C.
It is connected to the base of PN type transistor TR3,
The first line to which each second line of V phase and W phase respectively corresponds
-The 2nd P of the 1st-3rd inverter circuits 52A-52C corresponding via the 2nd and 4th amplifiers 50B and 50D of the 3rd gate drive circuits 52A-52C, respectively.
It is connected to the base of the NP type transistor TR2 and the base of the first NPN type transistor TR4.

In the coil drive block 34, the U-phase, V-phase and W-phase coils 11 of the motor section 2 correspond to the first to third inverter circuits 52A to 52C, respectively.
At the connection midpoint between the collector of the first PNP transistor TR1 and the collector of the first NPN transistor TR3, and the connection midpoint between the collector of the second PNP transistor TR2 and the collector of the second NPN transistor TR4. Connected between.

As a result, in the coil drive block 34, the first to third PWM signals S4A to S4C provided via the first or second line for each of the U phase, V phase and W phase. Are converted into analog waveform drive currents Iu, Iv, and Iw in the corresponding first to third inverter circuits 52A to 52C, and these are applied to the corresponding U-phase, V-phase, and W-phase coils 11, respectively. Is made possible.

In the coil drive block 34,
The magnitudes of the drive currents Iu, Iv, and Iw supplied to the U-phase, V-phase, and W-phase coils 11 are detected by the current sensors 53 each including a coil provided in each of the first to third inverter circuits 52A to 52C. Then, as described above, the detection result is the first to third first to third drive current detection signals S3A to S3.
3C is sent to the first analog / digital conversion circuit 45 (FIG. 11) of the one-chip microcomputer 27 of the control board 23.

(3) One-chip microcomputer 27
Detailed configuration of each processing block of the operation processing block 40 of the 1-chip microcomputer 27, the rotor shaft rotation angle detection processing block 4
2, the configuration of the torque-three-phase current signal conversion processing block 43 and the current control processing block 44 will be described in detail.

(3-1) Detailed Configuration of Arithmetic Processing Block 40 First, as is apparent from FIG. 11, the arithmetic processing block 40 includes a CPU (Central Processing Unit) 60 and a ROM (Read Only Memory) storing various programs. )
61 and a RAM (Ra as a work memory for the CPU 60).
ndom Access Memory) 62, parallel communication input / output circuit 63 that supports general-purpose parallel communication, serial communication input / output circuit 64 that is an input / output interface circuit with a host controller, and 1 for servo interrupt.
A counter timer control circuit 65 for generating a servo interrupt signal S10 of [ms] cycle and a PWM pulse signal S11 of 50 [μm] cycle which is a PWM cycle, and a servo interrupt signal S from the counter timer control circuit 65.
The CPU 60 and the watchdog signal generation circuit 66 for generating the watchdog signal S12, which is a reference signal of a predetermined cycle of 1 [ms] cycle or more, for mutual determination by the CPU 60 via the CPU bus 67. It is configured by being connected to.

In this case, when the power supply voltage (5 [V]) is supplied from the host controller via the serial communication input / output circuit 64, the CPU 60 first executes parallel communication based on the initial program stored in the ROM 61. I / O circuit 63, I / O circuit 64 for serial communication, counter
The timer control circuit 65, the rotor shaft rotation angle detection processing block 42, the torque-3 phase current signal conversion processing block 43, and the current control processing block 44 are subjected to rising processing such as processing for setting various initial values and parameters.

As a result, the CPU 60, based on the servo interrupt signal S10 given from the counter / timer control circuit 65 and the corresponding program stored in the ROM 61, sets the target rotational torque T as described above.
The motor rotation control calculation process that generates 0, the phase advance control process, the temperature compensation control process, and the serial communication control process
Execute in time division within [ms]. The processing of the CPU 60 in each of these processing modes will be described later.

Here, the configuration of the serial communication input / output circuit 64 will be described. This serial communication input / output circuit 6
4 is configured to be compatible with both RS-232C serial communication system and synchronous serial communication system.

In practice, the serial communication input / output circuit 64 is
For example, during communication in the RS-232C serial communication system, communication is performed by transmitting and receiving a TXD signal as a transmission signal and an RXD signal as a reception signal using two lines. At this time, the data transfer rate is 9600 [bit /
Second], the transfer data length is 8 bits, the stop bit is 1 bit, and the start bit is 1 bit, and communication with the upper controller is performed in the transfer format by the data structure without the parity bit.

The serial communication input / output circuit 64 transmits / receives a TXD signal as a transmission signal, an RXD signal as a reception signal, and a synchronous clock signal using three lines during communication in the synchronous serial communication system. To communicate. At this time, the data transfer rate is 800 or 1500
[Kilobits / second], the synchronization character data is 2 bytes, and the transfer data length is 1 byte (8 bits) to several tens of bytes.

In this communication system, since data communication can be performed at high speed, commands can be given in real time. When transferring N bytes of data, the data structure of one frame is as follows: "sync character 1 + sync character 2 + data 1 (8 bits) + data 2 (8 bits) + ...
... + data N (8 bits) + sync character 1 + sync character 2 ".

(3-2) Detailed Structure of Rotor Shaft Rotation Angle Detection Processing Block 42 Next, the structure of the rotor shaft rotation angle detection processing block 42 will be described in detail. As a premise, the configuration of the rotor shaft magnetic pole angle sensor 22 (FIG. 1) will be described first.

First, in the rotor shaft magnetic pole angle sensor 22, the resin magnet 25 is magnetized to the same pole as the rotor magnet 8 and fixed to the rotor base 7 in the same phase as the rotor magnet 8. The magnetization pattern of the resin magnet 25 has a magnetic flux density φ (θp) shown in FIG.

[0063]

[Equation 1]

Are selected so that

Here, θ p is the magnetic flux angle of the rotor shaft 6. The relationship between the magnetic pole angle θp and the mechanical rotation angle θm of the rotor shaft 6 is given by the following equation, where P is the number of magnetic poles (4 in this embodiment).

[0066]

[Equation 2]

It can be expressed as

On the other hand, the first to the first rotor shaft magnetic pole angle sensors 22
The fourth Hall elements 26A to 26D face the resin magnet 25 as described above with reference to FIG.

[0069]

[Equation 3]

[0070]

[Equation 4]

[0071]

[Equation 5]

[0072]

[Equation 6]

It is mounted on the control board 23 so as to be located at the position given by.

In the equations (3) to (6), θ 0 indicates the coordinate position with the position of one coil 11 as the origin,
In the following, the pole center position of one U-phase coil 11A is set to θ0 = 0 (see FIG. 4A). Furthermore, the coordinate position θ0 is

[0075]

[Equation 7]

The adjacent coils 11B, 11 given by
F is the V phase, and the coordinate position θ0 is

[0077]

[Equation 8]

The coils 11F and 11C given by are set to the W phase. It should be noted that coils 11A and 18 with the pole center position at θ 0 = 0
0 [°] The opposing coils 11D are in the U phase.

Incidentally, the number of poles Ps of the stator iron core 10 (FIG. 3) is Ps.
(4 in the present embodiment) and resin magnet 25
The relation with the number of magnetic poles P of

[0080]

[Equation 9]

Is given by

Then, the first to fourth portions arranged as described above.
Outputs Sh1, Sh2, Sh3 of Hall elements 26A to 26D of
Sh4 is expressed by the following equation, where G0 is the sensor sensitivity coefficient of these first to fourth elements 26A to 26D and θm is the rotation angle of the rotor shaft 6.

[0083]

[Equation 10]

[0084]

[Equation 11]

[0085]

[Equation 12]

[0086]

[Equation 13]

It becomes as follows. Therefore, when the rotor shaft 6 makes one revolution, the signal levels of the outputs Sh1, Sh2, Sh3, Sh4 of the first to fourth Hall elements 26A to 26D change in proportion to the number P of magnetic poles of the resin magnet 25.

However, the rotor shaft 6 is actually
And an error in the squareness between the sensor surfaces of the first to fourth Hall elements 26A to 26D and an error in the concentricity occur. Therefore, these errors can be calculated as φe1, φe2, θe1, and θe2, respectively.
As the actual outputs Sh1 ', Sh2', Sh3 ', Sh4' of the first to fourth Hall elements 26A to 26D,

[0089]

[Equation 14]

[0090]

[Equation 15]

[0091]

[Equation 16]

[0092]

[Equation 17]

It becomes

Then, the first sensor signal Sh12 obtained by adding the outputs Sh1 'and Sh2' of the actual first and second Hall elements 26A and 26B (in the present embodiment, the first rotor signal shown in FIG. 9). Equivalent to the shaft magnetic pole angle sensor signal S2A)
And a second sensor signal Sh34 obtained by adding the respective outputs Sh3 ', Sh4' of the third and fourth Hall elements 26C, 26D (in the present embodiment, the second rotor shaft magnetic pole angle sensor signal of FIG. 9). Equivalent to S2B), assuming that θe1 and θe2 are sufficiently small,

[0095]

[Equation 18]

[0096]

[Formula 19]

Can be expressed as: The waveforms of the first and second sensor signals Sh12 and Sh34 are shown in FIG.

Then, these first and second sensor signals S
Based on h12 and Sh34, the rotor shaft 6
The magnetic pole angle θp and the rotor shaft magnetic pole rotation speed Pml can be obtained.

That is, first, the initial value is set to 0, and the magnetic pole angle calculation value θx is set,

[0100]

[Equation 20]

Is calculated.

If Eθx = 0 is not satisfied, θ
x is

[0103]

[Equation 21]

It is calculated by Here, Krp1 indicates a proportional gain and Kri1 indicates an integral gain, both of which are positive constants.

The equation (20) is calculated again using the calculated θx, and this is repeated until Eθx = 0. As a result, Eθx converges to zero, and θx is

[0106]

[Equation 22]

Which corresponds to the rotor shaft magnetic pole rotation angle Pml.

Further, when the rotor shaft magnetic pole rotation angle Pml is obtained in this way, the following equation is obtained between the rotor shaft magnetic pole rotation angle Pml and the magnetic pole angle θp.

[0109]

[Equation 23]

Since there is a relation of (1), the magnetic pole angle θp can also be obtained based on the rotor shaft magnetic pole rotation angle Pml. In the formula (23), Nx represents an integer of 0 or more.

Based on this principle, the rotor shaft rotation angle detection processing block 42 is constructed as shown in FIG. And this rotor shaft rotation angle detection processing block 4
2, the first and second rotor shaft magnetic pole angle sensor data D2A and D2B are given from the rotor shaft magnetic pole angle sensor 22 via the second analog / digital conversion circuit 46.
To the arithmetic unit 70.

At this time, the arithmetic unit 70 informs the arithmetic unit 70 of the magnetic pole angle arithmetic value θx calculated in advance from the function converter 71 as described later.
The sine value (sin θx) and cosine value (cos θx) of are given.

Thus, the calculator 70 calculates the equation (20) based on the first and second rotor shaft magnetic pole angle sensor data D2A and D2B and the sine value and cosine value of the magnetic pole angle calculation value θx calculated in advance. Is calculated to calculate the error between the magnetic pole angle θp given by the equation (2) and θx at that time, and the calculation result is sent to the first multiplier 72.

Then, this multiplication result is obtained by the following equation in the first multiplier 72.

[0115]

[Equation 24]

(Where S is the Laplace operator) is multiplied by the integral gain, the second multiplier 73 is multiplied by the proportional gain Krp1, and the adder 74 is multiplied by 1 / S.
(S is a Laplace operator) is multiplied.

As a result, the magnetic pole angle calculation value θ is obtained from the adder 74.
x is output and is sent to the function converter 71 and is also given to the magnetic pole angle calculator 75. Thus, the magnetic pole angle calculator 75 uses the calculated magnetic pole angle value θx at this time as the rotor shaft magnetic pole angle Pml in the register 41 (FIG. 11).
To store.

At this time, the magnetic pole angle calculator 75 also obtains the value of θp within the range from 0 to 2π while sequentially increasing the value of Nx in the equation (23) from 0, and determines this as the magnetic angle θp. Is sent to the torque-three-phase current signal conversion processing block 43.

In this way, the rotor shaft rotation angle detection processing block 42 detects the magnetic pole angle θp and the rotor shaft magnetic pole rotation angle Pml based on the first and second rotor shaft magnetic pole angle sensor data D2A, D2B.

The rotor shaft rotation angle detection processing block 4
2, the calculation processing of the magnetic angle θp and the rotor shaft magnetic pole rotation angle Pm1 as described above is performed based on the PWM pulse signal S11 given from the counter / timer control circuit 65 of the calculation processing block 40.

Therefore, the magnetic angle θp and the rotor shaft magnetic pole rotation angle Pm1 output from the rotor shaft rotation angle detection processing block 42 are the cycle of the PWM pulse signal S11.
It is updated every 50 [μs].

(3-3) Detailed Configuration of Torque-3 Phase Current Signal Conversion Processing Block 43 The torque-3 phase current signal conversion processing block 43 is shown in FIG.
As shown in FIG. 11, the target rotational torque T0 stored in the register 41 (FIG. 11) is compared with the PWM pulse cycle (50 [μs
]), And based on the target rotation torque T0 and the magnetic pole angle θp given from the rotor shaft rotation angle detection processing block 42 (FIG. 14),

[0123]

[Equation 25]

[0124]

[Equation 26]

[0125]

[Equation 27]

The first to third current command values Ur, Vr, and Wr are calculated by calculating, and these are sent to the current control processing block 44 (FIG. 11).

The first to third current command values Ur, V
The arithmetic processing of r and Wr is given by P from the counter / timer control circuit 65 of the arithmetic processing block 40.
It is performed based on the WM pulse signal S11. Therefore, the first to third current command values Ur, Vr and Wr are also PWM
It is updated every 50 [μs] which is the period of the pulse signal S11.

(3-4) Detailed Configuration of Current Control Processing Block 44 On the other hand, the current control processing block 44, as shown in FIG. 16, is made to correspond to the U-phase, V-phase and W-phase coils 11, respectively. First to third signal processing systems 84A including subtraction circuits 80A to 80C, first and second multiplication circuits 81A to 81C, 82A to 82C, and PWM converters 83A to 83C.
~ 84C are provided.

In the current control processing block 44, in the first to third signal processing systems 84A to 84C, the first to third signals supplied from the torque-3 phase current signal conversion processing block 43 (FIG. 15) are supplied. Current command value Ur, V
r, Wr and the first to third provided from the power board 24
Based on the drive current detection signals S3A to S3C, the first to third PWM signals S4A to S4C and the first to third reference signals S5A to are performed while performing predetermined signal processing including voltage fluctuation compensation processing. It is adapted to generate S5C.

In practice, the first to third signal processing systems 84A-8
In 4C, the subtraction circuits 80A to 80 subtract the errors between the supplied first to third current command values Ur, Vr and Wr and the first to third drive current detection signals S3A to S3C.
C and the detection result is detected by the first multiplication circuit 81A-
Send to 81C.

The first to third signal processing systems 84A to 8
In 4C, since this error is thereafter converged to 0, the Laplace operator is set to S in each of the first multiplication circuits 81A to 81C, and the following formula is applied to this error.

[0132]

[Equation 28]

The integral gain given by is multiplied, and the multiplication result is multiplied by the proportional gain Krp in the second multiplication circuits 82A to 82C.

Then, each of the following expressions obtained in this way

[0135]

[Equation 29]

[0136]

[Equation 30]

[0137]

[Equation 31]

Each of the second multiplication circuits 82A to 82A given by
The values X1, X2 and X3 output from 2C are U
The current values of the drive currents that should be actually applied to the phase 11, V phase, and W phase coils 11, and these values X1, X2, and X3 are provided to the corresponding PWM converters 83A to 83C.

Each of the PWM converters 83A to 83C has
The first to third PWM signals S4A to S4C and the first to third reference signals are controlled by controlling the pulse widths of the pulses of 50 [μs] cycles based on the supplied values X1, X2 and X3, respectively. Signals S5A-S5C are generated.

In practice, each of the PWM converters 83A-83C is
As shown in FIG. 17, the supplied values X1 and X2, respectively.
, X3 are set in an internal register (not shown), and the value X1 is set.
, X2, X3 are positive, the corresponding values X1, X2, X3
To a down counter (not shown) in the first PWM pulse signal generation circuit 85A at every rising edge of the PWM pulse signal S11 of 50 [μs] period given from the counter timer control circuit 65 of the arithmetic processing block 40. set.

This down counter is the CPU clock of the arithmetic processing block 40 (FIG. 11) (0.1 [μs
]) The counter value is decremented at each rising edge and the process stops at a zero value. Therefore, the output of the first PWM pulse signal generation circuit 85A becomes the logic "1" level until the count value of the down counter reaches the zero value, and becomes the logic "0" level after the count value becomes the zero value. .

At the next rising edge of the PWM pulse signal S11, the values X1, X2,
X3 is set again in the down counter of the first PWM pulse signal generation circuit 85A, and the above processing is repeated.

Therefore, the first PWM pulse signal generation circuit 8
From 5A, the values X1, X2, X3 stored in the register
Until the value is updated, the first to third PWM signals S4A to S4A having a constant pulse width Ton proportional to the values X1, X2, and X3.
S4C is output and the second PWM pulse signal generation circuit 8
From 5A, reference signals S5A to S5 of logic "0" level
C is output.

On the other hand, in each of the PWM converters 83A to 83C, when the values X1, X2, and X3 are negative values, the absolute value is calculated and converted into a positive integer, and then this value is converted to the first value. The down counter (not shown) in the PWM pulse signal generating circuit 85B of No. 2 is set.

As a result, at this time, the values X1, X2, X3 stored in the registers are updated from the second PWM pulse signal generation circuit 85B in the same manner as the above-mentioned first PWM pulse signal generation circuit 85A. Up to the relevant value X1,
First to third constant pulse width Ton proportional to X2 and X3
PWM signals S4A to S4C are output. Further, at this time, the first PWM pulse signal generation circuit 85B outputs the reference signals S5A to S5C of the logic "0" level.

Thus, in the first to third PWM converters 83A to 83C, the supplied values X1, X2,
First to third PWM signals S having a pulse width Ton according to X3
4A to S4C and first to third reference signals S5A to S5C
Are generated and sent to the coil drive block 34 of the power board 24 via the third cables 33, respectively.

(4) Relationship between coil drive current and output torque Here, U of the motor unit 2 in this AC servomotor 1 is used.
Current I applied to each phase 11, V phase and W phase coil 11
The relationship between u, Iv, and Iw and the rotational torque output to the outside through the output shaft 18 (hereinafter referred to as output torque) will be described.

First, when the driving currents Iu, Iv, and Iw are applied to the U-phase, V-phase, and W-phase coils 11, the magnetic flux densities of the U-phase, V-phase, and W-phase coils 11 intersecting are φu, If φv and φw, output torque T (θp)
Is the following equation using the magnetic pole angle θp of the rotor shaft 6 of the motor unit 2.

[0149]

[Equation 32]

It is given as follows. In this equation (32), K0 is the drive current Iu, Iv,
It represents a constant coefficient value when Iw is applied.

Here, each coil 11 of U phase, V phase and W phase
The drive currents Iu, Iv, and Iw applied to the

[0152]

[Expression 33]

[0153]

[Equation 34]

[0154]

[Equation 35]

Therefore, the magnetic flux densities of φu, φv, and φw are expressed by the following equations, respectively.

[0156]

[Equation 36]

[0157]

[Equation 37]

[0158]

[Equation 38]

It becomes

Therefore, the output torque T (θp) is calculated by the following equation by substituting the equations (33) to (38) into the equation (32).

[0161]

[Formula 39]

It can be expressed as

Therefore, in this AC servomotor 1, it can be seen that an output torque proportional to the magnitude of the drive currents Iu, Iv, Iw applied to each coil 11 can be obtained.

(5) Software Control in AC Servo Motor 1 Next, the arithmetic processing block 40 of this AC servo motor 1 will be described.
The software control in FIG. 11 will be described.

In the arithmetic processing block 40, the CPU 60 controls the counter / timer / control circuit 65 as described above.
Based on the servo interrupt signal S10 given from the above and the corresponding program stored in the ROM 61, the motor rotation control calculation process, the phase advance control process, in a time division manner within 1 [ms],
The temperature compensation control process and the serial communication control process are executed. The processing of the CPU 60 in each of these processing modes will be described below.

(5-1) Processing of CPU 60 in Motor Rotation Control Calculation Processing Mode The processing of CPU 60 in the motor rotation control calculation processing mode is the designated rotation position, designated rotation speed or designation given from the host controller as described above. The target rotational torque T0 is calculated according to the designation of the rotational torque value.

When the designated rotation position Pref is given from the host controller, the CPU 60 applies the target rotation torque T0 to the rotor shaft magnetic pole rotation angle stored in the register 41 by the rotor shaft rotation angle detection processing block 42. The rotational position Pm of the output shaft 18 (FIG. 1) is calculated based on Pm1, and this rotational position Pm is used to calculate the following equation.

[0168]

[Formula 40]

[0169]

[Formula 41]

The target rotational speed Vmref with respect to the designated rotational position Pref and the current rotational speed Vm of the output shaft are calculated by respectively calculating From the expressions (40) and (41) thus obtained, the following expression

[0171]

[Equation 42]

The target rotation torque T0 is calculated by executing the calculation of.

Also, the designated rotation speed V is sent from the host controller.
When ref is given, the current rotational speed Vm of the output shaft 18 is calculated using the equation (41), and the following equation is calculated based on this rotational speed Vm.

[0174]

[Equation 43]

By calculating the target rotational torque T0
To calculate. When the designated rotation torque Tref is given from the host controller, this is directly used as the target rotation torque T0.

In these equations (40) to (43), S represents a Laplace operator, and Kpp, Kvi and Kvp represent control gain parameters set by the host controller. This control gain parameter Kpp, K
By changing the values of vi and Kvp, the response of the AC servomotor 1 to the designated rotation angle Pref and the designated rotation speed Vref can be changed.

Incidentally, a concrete processing procedure of the CPU 60 in such a motor rotation control calculation processing mode is shown in FIG.
Shown in.

When the designated rotation angle Pref is given from the host controller, the CPU 60 firstly stores the first and second absolute angle sensor data D1 stored in the register 41.
Based on A and D1B, the magnetic pole rotation speed of the rotor shaft 6 (hereinafter,
Nm of the rotor shaft magnetic pole rotation number) is calculated (step SP1).

The rotor shaft magnetic pole rotational speed Nm means the first to the first values of the rotor shaft magnetic pole angle sensor 22 as the rotor shaft 6 rotates.
The change in magnetic flux due to a pair of adjacent N and S poles of the resin magnet 25 detected by the fourth Hall elements 26A to 26D is defined as the number of revolutions. In this embodiment, since the resin magnet 25 is magnetized to have four poles, the rotor shaft magnetic pole rotation number Nm becomes 2 when the rotor shaft 6 makes one mechanical rotation.

The rotor shaft magnetic pole rotational speed Nm is calculated according to the rotor shaft magnetic pole rotational speed detection processing procedure shown in FIG.
Phase θ of the first and second one-rotation absolute angle sensor signals S1A, S1B represented by sin θg and cos θg, respectively.
g is calculated by software processing based on the first and second absolute angle sensor data D1A, D1B stored in the register 41 (step SP1A), and the phase θg of the planetary gear mechanism unit 16 of the torque amplification unit 3 is calculated. The gear ratio N is multiplied (step SP1B), the multiplication result is divided by 2π, and the integer part of the division result is the number of magnetic poles of the resin magnet 25 of the rotor shaft magnetic pole angle sensor 22 (FIG. 1) (the present embodiment). Can be obtained by multiplying by half the value Np of 4) (step SP1C).

Further, the CPU 60, as shown in FIG.
The rotor shaft magnetic pole rotation speed Nm calculated in this way and the rotor shaft magnetic pole rotation angle data P stored in the register 41
Based on m1 and

[0182]

[Equation 44]

With Pm0 given by as the initial value,

[0184]

[Equation 45]

The rotation angle Pm of the output shaft 18 at that time is calculated by executing the calculation of (step SP).
2).

Then, the CPU 60 sends the designated rotation angle Pref.
By subtracting this rotation angle Pm from, an error (hereinafter referred to as a rotation angle error) Pe with respect to the designated rotation angle Pref is detected (step SP3).

Subsequently, the CPU 60 determines the rotation angle error P
The target rotation angle Vmref with respect to the designated rotation angle Pref is calculated by multiplying e by the proportional gain Kpp (step SP4).

Next, the CPU 60 calculates the rotational speed Vm of the output shaft at that time by differentiating the rotor shaft magnetic pole rotation angle Pm1 stored in the register 41 (step SP5), and thereafter the target calculated in step SP4. The speed error Ve is calculated by subtracting the rotation speed Vm calculated in step SP5 from the rotation speed Vmref (step SP6).

Subsequently, the CPU 60 calculates the speed error Ve by the following equation.

[0190]

[Equation 46]

The velocity integral gain and the proportional gain Kvp given by are successively multiplied (steps SP7 and S).
P8). As a result, the target rotation torque T0 can be obtained.

In the motor rotation control calculation processing mode, the CPU 60 receives the designated rotation speed Vref from the host controller.
Is started, the process is started from step SP6. When the rotational torque Tref is given, this process is used as it is as the target rotational torque T0 in the register 4
Store in 1.

(5-2) Processing of the CPU 60 in the phase advance control processing mode First, the phase advance control will be described. U phase of the motor unit 2, V
Drive current Iu to be supplied to each phase 11 and W phase coil 11,
The Iv and Iw are controlled by the torque-three-phase current signal conversion processing block 43 and the current control processing block 44, respectively, so that they become equations (33), (34), and (35), respectively.

At this time, for example, when the rotor 9 is rotating at a high speed, the inverter circuits 52A to 5A of the power board 24 are formed.
Even if the drive currents Iu, Iv, and Iw as shown in the equations (33), (34), and (35) are given to 2C, the drive currents actually flowing in the U-phase, V-phase, and W-phase coils 11 are given. I
u, Iv, and Iw are delayed by the impedance of the coil 11, and as a result, the output torque is reduced.

The phase advance control is performed by the following equation in order to improve this problem.

[0196]

[Equation 47]

[0197]

[Equation 48]

[0198]

[Equation 49]

Each coil 1 of U phase, V phase and W phase as shown in
This is a control in which the phases of the drive currents Iu, Iv, and Iw applied to 1 are advanced in advance by a correction value θoff corresponding to the rotation speed of the rotor 9.

In actuality, the CPU 60 uses the rotation speed Vm calculated in step SP5 in FIG.

[0201]

[Equation 50]

The torque-three-phase current signal conversion processing block 43 is calculated according to the above equations and applied to the torque-three-phase current signal conversion processing block 43 to generate the first to third current command values Ur and Vr. , Wr are controlled so as to advance the phase by the correction value θoff as in equations (47) to (49).

In the equation (50), Kv is the output shaft 1
8 is a gain that determines the relationship between the magnitude of the rotation speed and the amount of phase advance correction, and is a constant determined by the specifications of each coil 11 of the motor unit 2.

(5-3) Processing of CPU 60 in temperature compensation control processing mode In an AC servomotor using a permanent magnet, heat is generated by the current flowing through the coil and heat is generated by eddy current loss. Such heat changes the magnetic characteristics of the permanent magnet. Generally, when a coil current is passed in a high temperature atmosphere and a high magnetic flux density is applied, the permanent magnet is demagnetized. Therefore, the maximum value of the coil current is generally designed to be low in order to ensure safety.

The temperature compensation control is control for effectively utilizing the magnetic characteristic of the permanent magnet by controlling the maximum current allowed by the temperature.

In the case of this embodiment, as shown in FIG. 9, the temperature sensor signal S14 output from the temperature sensor 29 of the control board 23 is the one-chip microcomputer 27.
It is stored in the register 41 as the temperature sensor data D14 via the fourth analog / digital conversion circuit 48.

Then, the CPU 60 calculates the maximum value Imax of I0 in the equations (33) to (35) based on the value TH of the temperature sensor data D14 by the following equation.

[0208]

[Equation 51]

The drive current Iu supplied to each of the U-phase, V-phase and W-phase coils 11 of the motor unit 2 is calculated by controlling the torque-three-phase current signal conversion processing block 43 based on the calculation result. , Iv and Iw are set. Kth is a temperature coefficient determined according to the temperature characteristics of the permanent magnet (the rotor magnet 8 (FIG. 1) of the rotor 9 in the present embodiment).

(5-4) Processing of CPU 60 in serial communication processing mode In the serial communication processing mode, the CPU 60 communicates with the host controller, inputs control commands and change parameters, or internally monitors for monitoring. Send a signal.

(5-5) Processing of CPU 60 in external force estimation processing mode Here, in the case of this AC servomotor 1, the arithmetic processing block 40 has the above-described motor rotation control arithmetic processing, phase advance control processing, and temperature compensation. In addition to the control process and the serial communication control process, the magnitude of the external force (load torque) applied to the output shaft 18 can be estimated.

In this case, the output torque Tm of a general motor, the mechanical rotation angle θm of the rotor, the external force Td applied to the output shaft, and the output angle of the gear mechanism (hereinafter referred to as the rotation angle of the output shaft). The relationship with θg can be expressed as shown in FIG.

That is, the mechanical rotation angle θm of the rotor
Is the output torque Tm subtracted from the structural load torque Tdm of the gear mechanism.

[0214]

[Equation 52]

It can be calculated by multiplying by. Note that Jm represents the moment of inertia of the rotor, and Dm represents the coefficient of friction with the bearing of the rotor.

The rotation angle θg of the output shaft is determined by the external force Td.
And a multiplication result (hereinafter, referred to as structural output shaft load torque) Tdl obtained by multiplying the structural load torque Tdm of the gear mechanism by the gear ratio N of the gear mechanism, and the addition result Tdl
To

[0217]

[Equation 53]

It can be calculated by multiplying by. Jl is the moment of inertia of the gear mechanism, Dl
Indicates a friction coefficient in the gear mechanism, and S indicates a Laplace operator.

The structural load Tdm of the gear mechanism is obtained by subtracting the multiplication result obtained by multiplying the rotation angle θg of the output shaft by the gear ratio N in the gear mechanism from the mechanical rotation angle θm of the motor rotor, and by subtracting the result, the gear mechanism. It can be calculated by multiplying the spring coefficient Kg at.

Based on this principle, the CPU 60 estimates the magnitude of the external force applied to the output shaft 18 from the outside according to the following procedure shown in FIG.

That is, the CPU 60 first generates an appropriate initial value as an external force estimated value (hereinafter referred to as an external force estimated value) Tde, and the external force estimated value Tde and the structure of the planetary gear mechanism 16 are structurally determined. The addition result of the output shaft load torque Tdl is

[0222]

[Equation 54]

A mathematical model rotation angle θgm of the output shaft 18 is calculated by multiplying by.

Then, by subtracting this rotation angle θgm from the actual rotation angle θg of the output shaft 18 obtained by calculation, the error of the rotation angle θgm of the mathematical model with respect to the actual rotation angle θg (hereinafter, this is referred to as the model error). Call) E
θg is calculated and this model error Eθg is given by

[0225]

[Equation 55]

The external force estimated value Tde is calculated by multiplying the estimated gain given by. In the equation (55), Ka is a constant positive coefficient value.

The CPU 60 then determines the external force estimated value T
The above calculation process is repeated while sequentially updating de to the newly obtained external force estimated value Tde. As a result, by repeating such calculation processing, the model error Eθg converges to a zero value, and along with this, the external force estimated value Tde also approaches the magnitude of the external force actually applied to the output shaft 18.

The external force estimated value Tde when the model error Eθg becomes 0 can be estimated as the external force actually applied to the output shaft 18, and the CPU 60 estimates this value as the external force estimated value obtained by calculation. Tde.

Then, the CPU 60 thereafter transmits this external force estimated value Tde to the host controller or, under the control of the host controller, antagonizes the external force given to the output shaft 18 based on this external force estimated value Tde. The generation and output torque control of the output torque, the generation and output control of the output torque that exceeds the external force, or the generation and output control of the output torque that falls below the external force are executed.

In the case of this embodiment, the magnitude of the external force applied to the output shaft 18 is estimated based on the rotational displacement of the output shaft 18 detected by the one-rotation absolute angle sensor 21 as described above. It is done like this. Therefore, the reduction mechanism of the torque amplification unit 3 (planetary gear mechanism 16)
Is constructed so as to have reversible driveability (back drivability) sufficient to cause displacement of the input shaft (rotor shaft 6) in proportion to the external force applied to the output shaft 18.

(6) Operation and Effect of the Present Embodiment In the above-mentioned configuration, in the AC servomotor 1, the control board 23 is set to 1 based on the designated rotation angle, designated rotation speed or designated rotation torque given from the host controller. Driving currents Iu, Iv to be applied to the U-phase, V-phase and W-phase coils 11 in the chip microcomputer 27,
First to third current command values Ur, Vr, W which are values of Iw
Each r is calculated, and the first to third PWM signals S4A to S4C based on the calculated first to third current command values Ur, Vr, and Wr are sent to the coil drive block 34 of the power board 24.

Then, the coil drive block 34 of the power board 24 supplies the supplied first to third PWM signals S4A.about.
Generate drive currents Iu, Iv, Iw based on S4C,
The rotor 9 is rotationally driven by applying this to the U-phase, V-phase, and W-phase coils 11.

In this AC servomotor 1, the control board 23 and the power board 24 as the control means for controlling the rotation of the rotor 9 as described above are integrated with the rotor 9 and the stator composed of the stator core 10A and the coil 11. Since it is housed inside the motor case 4, the amount of wiring connected to the outside can be significantly reduced, and
The amount of wiring in the entire actuator system can also be reduced.

Also in this case, the PWM converter 83
A to 83C (switching elements) are housed inside the motor case 4 made of a conductive material. Therefore, for example, when a PWM signal (switching signal) is externally applied to the AC servomotor like a conventional AC servomotor. In comparison, it is possible to significantly reduce the adverse effects of switching noise on the outside. Also, from this fact, a relatively common cable can be used as the second cable 32 for connecting the AC servomotor 1 and the host controller.

Furthermore, in this AC servomotor 1, the rotor shaft magnetic pole angle sensor 22 is arranged in the vicinity of the rotor 9 inside the motor case 4, and the rotor rotation angle θm is obtained based on the output of the rotor shaft magnetic pole angle sensor 22. Therefore, it is possible to perform high-accuracy and high-speed positioning without making the rotor shaft 6 thick, and accordingly, it is possible to construct a small size as a whole.

In addition, the rotor shaft magnetic pole angle sensor 2
Since 2 is arranged near the rotor 9 inside the motor case 4, there is little mechanical fluctuation, and the rotation angle of the rotor shaft 6 can be detected stably.

Further, in this AC servomotor 1, since the temperature sensor 29 is provided in the motor case 4 in the vicinity of the rotor magnet 8, the temperature sensor 2 is not provided.
Based on the output of 9, the drive current Iu that can be actually applied to each coil 11 according to the magnetic characteristics of the rotor magnet 8,
The upper limits of Iv and Iw can be accurately and easily obtained, and the upper limits of the drive currents Iu, Iv, and Iw can be increased as compared with the conventional case where the upper limits are set to include safety. The maximum output torque can be increased.

Further, in this AC servomotor 1, since the rotor 9 and the control circuit for controlling the rotation of the rotor 9 are arranged on a plane, it can be constructed in a small and flat shape.

Further, the AC servomotor 1 has a simple structure and a small number of parts, so that there is an advantage that the assembling work and the adjusting work at the time of manufacturing can be facilitated.

According to the above configuration, the control board 23 for controlling the rotation of the motor section 2 under the control of the host controller.
And the power board 24 is housed inside the motor case 4 integrally with the rotor 9 and the starter.
An AC that can significantly reduce the amount of wiring connected to the outside of the C servomotor 1 and can also reduce the amount of wiring of the entire actuator system, thus simplifying the configuration of the entire actuator system. Servo motor can be realized.

Since the rotor shaft magnetic pole angle sensor 22 for detecting the rotation angle of the rotor shaft 6 is arranged in the motor case 4 in the vicinity of the rotor 9, the rotor shaft 6 can be accurately and quickly operated without being thickened. It is possible to realize positioning, and thus it is possible to realize an AC servomotor that can be downsized while improving performance.

Further, since the temperature sensor 29 is provided inside the motor case 4 in the vicinity of the rotor magnet 8, based on the output of the temperature sensor 29,
The upper limits of the drive currents Iu, Iv, and Iw that can be actually applied to each coil 11 can be accurately and easily obtained according to the magnetic characteristics of the rotor magnet 8, and the drive current Iu can be calculated accordingly.
It is possible to increase the maximum output torque by increasing the upper limit of Iv, Iv, and Iw as compared with the conventional case in which the safety is set, and thus, the AC servomotor capable of improving the performance is realized. it can.

(7) Other Embodiments In the above-mentioned embodiments, the case where the present invention is applied to the AC servomotor has been described. However, the present invention is not limited to this, and in short, rotation is essential. A freely rotatable pivot shaft (rotor shaft 6 in the present embodiment) and drive means for rotationally driving the rotary shaft (rotor 9, stator iron core 10 and a stator in the present embodiment).
If and are the actuator devices housed in the housing (motor case 4 in the present embodiment), they can be widely applied to various other actuator devices.

Further, in the above-mentioned embodiment, the case where the rotor magnet 8 is magnetized to have four poles has been described, but the present invention is not limited to this, and for example, eight poles or the number of poles other than this is used. It may be magnetized.

Further, in the above-mentioned embodiment, the case where the control board 23 and the power board 24 as the control means for controlling the rotation of the rotor 9 are separately formed is described, but the present invention is not limited to this. Not limited to this, they may be integrally formed.

Further, in the above-described embodiment, the case where the one-chip microcomputer 27 controls the rotation of the rotor 9 based on the designated rotation angle, the designated rotation speed or the designated rotation torque given from the host controller will be described. However, the present invention is not limited to this, and the rotation of the rotor 9 may be controlled based on, for example, a preprogrammed rotation angle or a change pattern of the rotation speed or the rotation torque.

Further, in the above-described embodiment, the rotor shaft magnetic pole angle sensor 22 as the rotary shaft rotational displacement detecting means for detecting the rotational displacement of the rotor shaft 6 is magnetized in a predetermined pattern into the resin magnet 25 (first Component) and the first
The case where the fourth hall elements 26A to 26D (the second component) are used has been described, but the present invention is not limited to this, and various other configurations can be widely applied.

Further, in the above-mentioned embodiment, the case where the magnetic pole angle θp of the rotor shaft 6 is detected as the rotational displacement of the rotor shaft 6 has been described, but the present invention is not limited to this, and the magnetic pole angle θp is not limited to this. Other rotational displacement information may be detected.

Further, in the above-described embodiment, the coil 11 is used as a magnetic field generating means for generating a magnetic field having a magnitude corresponding to the current values of the drive currents Iu, Iv, Iw supplied from the power substrate 24 in the rotor section 2. Although the case where it is applied has been described, the present invention is not limited to this, and various other magnetic field generating means can be widely applied.

Further, in the above embodiment, U
Current I applied to each phase 11, V phase and W phase coil 11
The case where the drive current value detecting means for detecting the current values of u, Iv, and Iw is configured by the coil 53 (FIG. 10) has been described, but the present invention is not limited to this, and the drive of various other configurations. The current value detecting means can be widely applied.

Further, in the above-described embodiment, the one-chip computer 27 of the control board 23 is provided with the RS- as a serial communication function for communicating with the host controller.
The case where the 232C serial communication function and the synchronous serial communication function are provided has been described, but the present invention is not limited to this, and other serial communication functions may be provided.

Further, in the above embodiment, the case where the torque amplifying means for amplifying the rotating torque generated in the motor section 2 is constituted by the planetary gear mechanism 16 as shown in FIG. 5 has been described. The present invention is not limited to this, and various other configurations can be widely applied.

Further, in the above embodiment, the one-rotation absolute angle sensor 21 as the output shaft rotational displacement detecting means for detecting the rotational displacement of the output shaft 18 is provided with the resin magnet 19.
The case where the first and second Hall elements 20A and 20B are configured has been described, but the present invention is not limited to this, and various other configurations can be widely applied.

Further, in the above-mentioned embodiment, the first and second 1 output from the one-rotation absolute angle sensor 21.
A load torque externally applied to the output shaft 18 based on the absolute rotation angle sensor signals S1A and S1B and the first and second rotor shaft magnetic pole angle sensor signals S2A and S2B based on the output of the rotor shaft magnetic pole angle sensor 22 ( The case where the calculating means for detecting (external force) is configured by the 1-chip microcomputer 27 has been described, but the present invention is not limited to this, and the calculating means may be provided separately from the 1-chip microcomputer 27. good.

Further, in the above-described embodiment, each drive current Iu is based on each drive current Iu, Iv, Iw applied to each U-phase, V-phase and W-phase coil 11 detected in the power board 24. , Iv, and Iw are feedback-controlled to reduce the influence of fluctuations in the power supply voltage, the present invention is not limited to this, and the V-phase and W-phase are controlled by open-loop control. Drive currents Iu, Iv, I applied to the respective coils 11 of
The current value of w may be controlled.

In practice, as such a method, the magnitude of the power supply voltage Vcm is detected, and the gain Gv in the current control processing block 44 is calculated by the following equation based on the detection result.

[0257]

[Equation 56]

It may be variable as shown in FIG.

[0259]

As described above, according to the present invention, in the actuator device in which the rotor rotatably supported and the stator for generating torque in the rotor are housed in the housing, the drive current is supplied to the stator. A driving circuit that holds the control gain parameter that determines the response characteristic to the designation of the rotation angle or the rotation speed given in advance, and calculates a current command value to be given to the drive circuit using the control gain parameter. By providing the housing in the housing, it is possible to integrate an arithmetic means for controlling the actuator device, and thus it is possible to realize an actuator device that can simplify the configuration of the actuator system.

Further, according to the present invention, a rotor rotatably supported, a stator for generating torque in the rotor,
In an actuator device having a housing for accommodating a rotor and a stator and a torque amplifying means for amplifying torque generated in the rotor and outputting the torque via an output shaft, a drive circuit provided in the housing and supplying a drive current to the stator An arithmetic means that is provided in the housing, holds a control gain parameter that determines a response characteristic to a designated rotation angle or rotation speed, and calculates a current command value to be given to the drive circuit using the control gain parameter. And a rotation angle detecting means provided in the torque amplifying means for detecting the rotation angle of the output shaft, and the calculating means is
An estimated value of the external force applied to the output shaft of the torque amplification means is calculated from the detection result of the rotation angle detection means using a mathematical model of the torque amplification means given in advance, and the current command value is calculated according to the estimation result. By making the determination, the calculation means for controlling the actuator device can be integrated, and thus the actuator device that can simplify the configuration of the actuator system can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an AC servomotor according to the present embodiment.

FIG. 2 is a schematic diagram showing a configuration of a rotor and a rotor shaft magnetic pole angle sensor.

FIG. 3 is a schematic diagram showing a positional relationship between a rotor and a stator iron core.

FIG. 4 is a schematic diagram showing a configuration of a stator and a power board.

FIG. 5 is a schematic diagram showing a configuration of a torque amplification unit.

FIG. 6 is a characteristic curve diagram for explaining a magnetization pattern of a resin magnet in a one-rotation absolute angle sensor.

FIG. 7 is a characteristic curve diagram showing a waveform of a one-rotation absolute angle sensor signal.

FIG. 8 is a schematic diagram showing a configuration of a control board.

FIG. 9 is a block diagram showing a configuration of a control board.

FIG. 10 is a circuit diagram showing a configuration of a power board.

FIG. 11 is a block diagram showing a configuration of a one-chip microcomputer.

FIG. 12 is a characteristic curve diagram for explaining a magnetization pattern of a resin magnet in a rotor shaft magnetic pole angle sensor.

FIG. 13 is a characteristic curve diagram showing waveforms of first and second sensor signals (first and second rotor shaft magnetic pole angle sensor signals).

FIG. 14 is a block diagram showing a configuration of a rotor shaft rotation angle detection processing block.

FIG. 15 is a block diagram showing a configuration of a torque-3 phase current signal conversion processing block.

FIG. 16 is a block diagram showing a configuration of a current control processing block.

FIG. 17 is a schematic diagram used to describe a process of a PWM converter.

FIG. 18: CPU in motor rotation control processing mode
3 is a block diagram provided for explaining the arithmetic processing of FIG.

FIG. 19 is a block diagram showing a motor shaft magnetic pole rotation speed detection processing procedure.

FIG. 20 is a block diagram showing a mathematical model of the relationship between the rotor and the gear mechanism.

FIG. 21 is a block diagram for explaining the calculation processing of the CPU in the external force estimation processing mode.

[Explanation of symbols]

1 ... AC servo motor, 2 ... motor part, 3 ... torque amplification part, 4 ... motor case, 6 ... rotor shaft, 8 ...
… Rotor magnet, 9 …… Rotor, 10, 10A-1
0F ... Stator core, 11, 11A to 11F ... Coil, 16 ... Planetary gear mechanism, 18 ... Output shaft, 19, 2
5: Resin magnet, 20A, 20B, 26A to 26
D: Hall element, 21 ... 1-turn absolute angle sensor, 2
2 ... Rotor shaft magnetic pole angle sensor, 23 ... Control board, 2
4 ... Power board, 27 ... 1-chip microcomputer, 29 ... Temperature sensor, 31-33 ... Cable,
34 ... Coil drive block, 40 ... Arithmetic processing block, 42 ... Rotor shaft rotation angle detection block, 43 ...
Torque-3 phase current signal conversion processing block, 44 ... Current control processing block, 52A-52C ... Inverter circuit, 60 ... CPU, 64 ... Serial communication input / output circuit, 83A-83C ... PWM converter, S1A, S1B
...... 1 rotation absolute angle sensor signal, S2A, S2B ...... Rotor shaft magnetic pole angle sensor signal, S3A to S3C ...... Drive current detection signal, S4A to S4B ...... PWM signal, S13 ...
... Temperature sensor signal, Ur, Vr, Wr ... Current command value,
Iu, Iv, Iw ... drive current, θp ... magnetic angle, P
m1 ... Rotor shaft magnetic pole rotation angle, Pref ... Designated rotation angle, Vref ... Designated rotation speed, Tref ... Designated rotation torque, T0 ... Target rotation torque, Tde ... External force estimated value.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H02P 6/16 H02K 11/00 CE H02P 6/02 341N (56) Reference JP-A-8-265919 (JP, A) Kaihei 8-75831 (JP, A) JP 10-264057 (JP, A) JP 10-296400 (JP, A) JP 8-87330 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) H02P 6/06 H02K 11/00 H02K 21/14 H02K 29/08 H02P 5/41 H02P 6/16

Claims (3)

(57) [Claims] 1. An actuator device in which a rotor rotatably supported and a stator for generating torque in the rotor are housed in a housing, and a drive circuit for supplying a drive current to the stator is provided in advance. Also , for the designation of rotation angle or rotation speed
Holds the control gain parameter that determines the response characteristics ,
An actuator device, characterized in that the housing is provided with a calculating means for calculating a current command value to be given to the drive circuit using the control gain parameter . 2. A temperature detecting means provided in the housing for detecting a temperature of a permanent magnet for driving which constitutes the rotor, wherein the calculating means is responsive to a temperature characteristic of the permanent magnet given in advance. 2. The actuator device according to claim 1, wherein the current command value is determined based on the detection result of the temperature detection means using a temperature coefficient determined by the above. 3. A rotor rotatably supported, a stator for generating torque in the rotor, a housing for accommodating the rotor and the stator, and an output shaft for amplifying the torque generated in the rotor. in the actuator device having a torque amplifying means for outputting through, provided on said housing, a drive circuit for supplying a drive current to the stator, provided in the housing, given in advance, the rotation angle
Alternatively, the control gain parameter for determining the response characteristic to the designation of the rotation speed is held, and the control gain parameter is used to calculate a current command value to be given to the drive circuit. And a rotation angle detecting means for detecting a rotation angle of the output shaft, wherein the computing means uses the mathematical model of the torque amplifying means given in advance to detect the torque from the detection result of the rotation angle detecting means. An actuator device, characterized in that an estimated value of an external force applied to the output shaft of the amplification means is calculated, and the current command value is determined according to the estimated result.