JPH0640684B2 - Electric vehicle control device - Google Patents

Description

The present invention relates to a control device for an electric vehicle using a microcomputer, and more particularly to a control device for an electric vehicle suitable for detecting a current of an electric motor that drives a chipper.

When the conventional electric motor is controlled by the microcomputer, the electric current of the electric motor is taken in once in one cycle of the chipper. According to this method, when the electric motor is driven by the tipper, the current flowing through the electric motor changes considerably while the tipper is turned off from the tipper.Therefore, depending on the timing of the current flowing into the electric motor, the average current actually flowing in the electric motor and However, there is a drawback in that suitable control is not performed.

FIG. 1 is a diagram showing the relationship between the rotational speed and the torque of a conventional armature. Since the conventional electric vehicle control device has taken in only one point of current as described above, it has characteristics as shown by the solid line, and the running load shown by the broken line intersects at points a and b2. This indicates that when the running load changes due to the unevenness of the road surface, the vehicle speed increases or decreases and is not stable, resulting in unsmooth driving.

FIG. 2 is a diagram showing a comparison of changes in the armature current of a conventional electric vehicle controller, in which the armature current changes in a sawtooth shape. Conventionally, either the valley current of the sawtooth or the peak current has been detected. As a result, the suitable control has not been performed as described above.

In order to improve this, a filter is inserted to eliminate the sawtooth pulsation and averaged, which is the case when the filter shown by the broken line is used. Although this seems to have been improved at first glance, the feedback back operation is delayed, and when the current increases rapidly, the command to reduce the current is delayed. As a result, the commutation capacity of the chipper circuit will be destroyed unless it is given a sufficient margin, and a large-scale main circuit with a considerable margin is required, which is expensive, which is not preferable.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide an electric vehicle control device capable of detecting the average current of the electric motor in a short time and performing suitable control. A chopper circuit to apply,
A microcomputer that detects the operating states of the battery, the electric motor, the chopper circuit, and the accelerator pedal and the armature current of the electric motor to calculate a chopper conduction ratio, and outputs a signal for turning on / off the chopper circuit. And a means for generating an interrupt pulse to the microcomputer by detecting an ON signal output from the microcomputer, and an OFF signal output from the microcomputer by detecting an OFF signal output from the microcomputer. Means for generating an interrupt pulse in the computer, means for inputting the armature current according to the interrupt program activated by the on-time interrupt pulse, and the armature current according to the interrupt program activated by the off-time interrupt pulse Means for inputting the A first feature is that the means for calculating the average value of the armature current from the current value input by the interrupt program at the time of turning off is provided, the means for detecting the voltage across the chopper circuit, and the chopper. Means for generating an interrupt pulse to the microcomputer when the voltage of the circuit falls, a means for generating an interrupt pulse to the microcomputer when the voltage of the chopper circuit rises, and a voltage falling of the chopper circuit Means for inputting the armature current according to an interrupt program activated by an interrupt pulse, a means for inputting the armature current according to an interrupt program activated by an interrupt pulse when the chopper circuit voltage rises, and the chopper circuit voltage Current input by the interrupt program at the fall and above rise A second feature is that the apparatus further comprises means for calculating an average value of the armature current from the value.

FIG. 3 is a block diagram of a control device for an electric vehicle which is an embodiment of the present invention. The microcomputer 1 is a microprocessor 2, a random access memory (hereinafter referred to as RAM) 3, a read only memory (hereinafter referred to as ROM).
4, an oscillator 5 and a bus line 6 for address and data control. Further, the analog input circuit 7 converts an analog electric signal ACA corresponding to the depression amount of the accelerator device 8 and an analog signal obtained by detecting the operating state of the main circuit 10 through the level conversion circuit 11 into a digital signal. It is a circuit to be taken in.

Reference numeral 14 is an interrupt circuit, and 15 is a conduction ratio control circuit of the chipper, which is a circuit that determines the on-time in one cycle, that is, the duty. The square wave of this output is the pulse distribution circuit 16
Are divided into on-pulse and off-pulse by. These pulse signals are amplified by the amplifier circuit 17, and the main circuit 10
It becomes a check signal in.

FIG. 4 is a circuit diagram of the interrupt circuit of FIG. It is a circuit for receiving the interrupt pulses INP1 to INP4 of four factors. When a pulse is generated at INP1, the flip-flop circuit 111 is set and the output IND1 becomes 1 level. On the other hand, the interrupt pulse INP1 is the OR circuit 1
It also serves as an input of 15 and gives an interrupt pulse INT to the microprocessor 2. As a result, Microprocessor 2
Then, the contents of IND are taken in and the reset pulse INRE of the flip-flop circuits 111 to 114 is generated. When the content of IND is checked and IND1 is at 1 level, it is determined that an interrupt has occurred in that portion, and the interrupt processing is executed. The same applies when an interrupt pulse enters INP2 to INP4.

FIG. 5 is a detailed diagram of the distribution rate control circuit 15, the pulse distribution circuit 16 and the amplification circuit 17 of FIG. Further, FIG. 6 is a diagram showing operation waveforms of the circuit of FIG. The distribution rate control circuit 15 includes a counter 116, a register 117, and a digital comparator 119.
Count the black CLOs made in. As a result, the output COUT of the counter 116 exhibits a sawtooth wave-like characteristic as shown in FIG. 6, and the value of the register 117 holding the duty ratio command DUA of the motor checker given by the microcomputer 2 is digitally compared. It is compared by the device 119. And in the digital comparator 119, register 1
When the value of 17 becomes larger than the value COUT of the counter, 1
Generate a square wave signal to level.

As shown in FIG. 5, the pulse distribution circuit 16 is a monostable circuit 122 that generates a pulse of a constant width in synchronization with the rising edge of the output square wave of the digital comparator 119, and similarly a pulse of a constant width in synchronization with the rising edge. The generated monostable circuit 123, inverters 118, 128 and 129 and two AND gate circuits 124 and 125. SUP, which is one of the inputs of the AND gate circuits 124 and 125, makes this signal zero level when the microcomputer 1 wants to stop the generation of pulses.

Now, when the SUP is at the 1 level, the outputs of the monostable circuits 122 and 123 are the same as those of the AND gate circuit 1.
The outputs are 24 and 125, which are signals such as APO and APF in FIG. The other pulse of the monostable circuits 122 and 123 becomes the interrupt pulses INP1 and INP2. INP1 and INP2 become the interrupt pulse of FIG. 4 described above, and interrupt the microprocessor 2.
Further, as shown in the operation waveform of FIG. 6, the pulse of INP1 is generated so as to coincide with APO, and INP2 is generated so as to coincide with APF. Further, each interrupt factor pulse INP1 to INP4
Becomes an input of the OR gate circuit 115 and is directly given to the interrupt terminal of the microprocessor 2 as an interrupt pulse INT.

The outputs of the AND gate circuits 124 and 125 are amplified by the pulse amplifiers 126 and 127 and become the gate pulse APGO and the gate pulse APGF of the thyristor of the thyristor catalyst circuit described later.

FIG. 7 is a circuit diagram of the main circuit 10 of FIG. 3, in which the battery current is controlled by the thyristor checker circuit 131 using the battery 130 as a power source. The thyristor checker circuit 131 includes a main thyristor 135 and an auxiliary thyristor 13.
6, a diode 137, a commutation capacitor 138, and a commutation reactor 139. Reference numeral 132 is an armature, 134 is a field winding, 140 is a plugging diode, and 141 is a flywheel diode. 146 and 147 are contactors, which are turned on by a manual lever provided in the driver's seat. These contactors 146, 147 move forward
The reverse is decided. That is, when either of the contactors 146 and 147 is turned on, it moves forward or backward. Note that FIG. 7 shows a neutral state, in which 148 is a protective fuse and 150 is a current detector.

The operation of the electric vehicle control device configured as described above will be described below. The operation of the control device shown in FIG. 3 is performed by sequentially processing the contents of the program written in the ROM 4. The programs written in this ROM 4 are roughly divided into two, and the first program is MAIN.
The processing contents of the program are shown in FIG.
The second program is an INT program which is moved by the generation of an interrupt pulse, and its processing contents are shown in FIG.

FIG. 8 is a flow chart of the MAIN program of the apparatus shown in FIG. 3. When the microcomputer 1 is energized, first, the block 201 is initialized, and each register shown in FIG. 1 and the RAM 3 are initialized. After that, it waits for an interrupt pulse.

FIG. 9 is a flow chart of the IRQ program, which is the INP of FIG.
It is executed when the interrupt pulse shown in is input. The IRQ program first determines in block 301 whether the interrupt is INP1 or INP2.

Since INP1 is synchronized with the on-pulse of the tipper, the electric current when the tipper is on can be obtained by taking in the electric current of the electric motor with the block 302 immediately after the interruption of the INP1. Similarly, since INP2 is synchronized with the off pulse of the tipper, the electric current of the electric motor at the time of tipping off the tipper can be taken into IM2 by taking in the electric current of the electric motor with the block 305 immediately after the interruption of the INP2. The block 303 calculates the average current IMM, and the block 304 calculates the flow rate with the accelerator output ACA, and outputs it as the flow rate command DUA.

FIG. 10 is a diagram in which the generation timings of the armature current and the interrupts INP1 and INP2 are associated with each other. Since INP1 is generated when the chip is turned on, the battery 1 shown in FIG.
Capture the beginning of the flow of current from 30 into the motor.
After that, the current flowing through the electric motor increases up to the tip-off by a constant determined by the resistance and inductance of the circuit and the rotation speed of the armature. INP2 when switching off
Occurs, the maximum value of the current flowing through the electric motor is captured.

FIG. 11 is a diagram showing the relationship between the rotation speed of the armature and the armature current of FIG. 3, and the relationship between the torque and the rotation speed of the armature is also as shown in FIG. Since the armature current is constant until it rises to a predetermined number of revolutions, the torque is constant even if the running load changes due to unevenness of the road surface or the like.

Since the control device for the electric vehicle of this embodiment is designed to determine the current flowing through the electric motor by calculating the fetched average current when the chip is turned on and off, the torque becomes constant even if the running load changes, and drivability is improved. Is improved. In addition, it is possible to obtain an effect that it can be constructed at low cost.

FIG. 12 is a block diagram of control of an electric vehicle according to another embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals. In this case, the signal from the main circuit 10 is fed back to generate an interrupt pulse.

FIG. 13 is a circuit diagram of the main circuit 10 shown in FIG.
The same parts as those in the figure are designated by the same reference numerals. At this time, the anode voltage VS1 of the main thyristor 135 is detected.
The voltage VS1 is applied from the battery 130 through the resistor R1. The level conversion circuit 11 shown in FIG. 14 is divided by resistors R2 and R3 as shown in FIG. 12, and noise is absorbed by the capacitor C1.

FIG. 15 shows the impedance converter 161 of FIG. 12, and impedance conversion is performed by such a buffer.

FIG. 16 shows the interrupt pulse generator 162 of FIG. 12, from which the interrupt pulse INP2 is generated. The program started by the interrupt pulse INP1 and the interrupt pulse INP2 by the voltage of the main thyristor 135 is as described in FIGS. 8 and 9. The interrupt generation timings of the interrupt pulses INP1 and INP2 are shown below in comparison with the operation of the main circuit.

FIG. 17 is a diagram showing operation waveforms of the control device of FIG. 12, the horizontal axis is time t, and the vertical axis is the commutation capacitor 138, the tip-on pulse APGO, and the tip-off pulse APGF of FIG. , Armature current I _M , thyristor voltage VS, and interrupt pulse operating waveforms, respectively. In the period (A), the APGO causes the main thyristor 135 shown in FIG. 13 to start conducting, and the armature current starts to flow.
At this time, the first interrupt pulse INP1 is generated,
The value of the current flowing through the armature 132 shown in FIG.

In the next period (B), the APGF is generated, the auxiliary thyristor 136 of FIG. 13 is ignited, and the charge charged in the commutation capacitor 138 starts to flow. During the periods (C), (D), and (E), the commutation condenser 138 and commutation reactor 13 shown in FIG.
9 is a period in which the voltage of the commutation capacitor 138 is inverted and a reverse bias is applied to the main thyristor 135 and the auxiliary thyristor 136. It is also a period during which the charging current flows through the commutation capacitor 138. During this period (F), when the capacitor voltage becomes positive, the second interrupt pulse INP2 is generated. At this time, when the armature current is small, the maximum current of one cycle of the chipper can be taken in.

As in the previous embodiment, the control device of the present embodiment takes in and averages the current that flows in the electric motor during turning on and off of the tipper, so even if it is the maximum when the tipper is fully opened, it is averaged within one cycle of the tipper cycle. Can be converted. Also,
Since averaging is performed by software, it is not necessary to use a filter for averaging, and there is no delay in the control system. Further, since the pulsation of the electric motor is calculated, the relationship between the maximum control current of the armature and the rotation speed becomes flat as shown in FIG. 11, so that it is stable against changes in load during road traffic,
And the feeling is improved. Also, since the number of interrupts is small, it has the effect of eliminating the complexity of software such as when there are multiple interrupts. That is,
It is even more accurate to take the maximum value of the armature current.

Since the control device for an electric vehicle of the present invention calculates the average current by taking in twice the turning on / off of the chipper in one driving cycle, the vehicle speed is significantly stabilized. Further, since the current when the chip is off is taken in, the peak current can be detected, and the effect that the chip of the chip circuit can be cut down and the cost can be relatively reduced can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the rotational speed and torque of a conventional armature, FIG. 2 is a diagram showing a comparison of changes in armature current of a conventional electric vehicle controller, and FIG. FIG. 4 is a block diagram of an electric vehicle controller which is an embodiment of the present invention, FIG. 4 is a circuit diagram of the interrupt circuit of FIG. 3, and FIG. 5 is a distribution ratio control circuit, pulse distribution circuit and amplifier circuit of FIG. 6 is a detailed diagram of FIG. 6, FIG. 6 is a diagram showing operation waveforms of the circuit of FIG. 5, FIG. 7 is a circuit diagram of the main circuit of FIG. 3, and FIG. 8 is a flow chart of the MAIN program of the apparatus of FIG. FIG. 9 is a flow chart of the IRQ program of the apparatus of FIG. 3, FIG. 10 is a diagram in which the armature current and the generation timings of the interrupts INP1 and INP2 are associated, and FIG. 11 is the rotation speed of the armature of FIG. And FIG. 12 is a block diagram of a control device for an electric vehicle which is another embodiment of the present invention. , FIG. 13 is a circuit diagram of a main circuit of Figure 12, Figure 14 is a circuit diagram of the level conversion circuit of Figure 12,
FIG. 15 is a circuit diagram of the impedance converter of FIG. 12,
FIG. 16 is a circuit diagram of the interrupt pulse generator 162 of FIG. 12, and FIG. 17 is a diagram showing operation waveforms of the control device of FIG. 1 ... Microcomputer, 2 ... Microprocessor, 3 ... RAM, 4 ... ROM, 5 ... Oscillator, 6 ...
... bus line, 7 ... analog input circuit, 8 ... accelerator device, 10 ... main circuit, 11 ... level conversion circuit, 1
4 ... Interrupt circuit, 15 ... Commutation rate control circuit, 16 ...
Pulse distribution circuit, 17 ... Amplifier circuit, 111-114 ...
… Flip-flop circuit, 115… OR gate circuit,
116 ... Counter, 117 ... Register, 118, 1
28,129 ... Inverter, 119 ... Digital comparator, 122, 123 ... Monostable circuit, 124, 12
5 ... AND gate circuit, 126, 127 ... Pulse amplifier, 130 ... Battery, 131 ... Thyristor checker circuit, 132 ... Armature, 134 ... Field winding,
135 ... Main thyristor, 136 ... Auxiliary thyristor,
137 ... Diode, 138 ... Commutation capacitor, 1
39 ... Commutation reactor, 140 ... Plugging diode, 146, 147 ... Contactor, 148 ... Protecting fuse, 150 ... Current detector, 161, ... Impedance converter, 162 ... Interrupt pulse generator.

Claims (2)

[Claims] 1. A chopper circuit for applying a voltage from a battery to an electric motor, operating states of the battery, the electric motor, the chopper circuit, and an accelerator pedal and an armature current of the electric motor are detected to determine a chopper conduction ratio. A controller for an electric vehicle having a microcomputer for calculating and outputting a signal for turning on / off the chopper circuit, means for detecting an on signal output from the microcomputer, and generating an interrupt pulse in the microcomputer. A means for generating an interrupt pulse in the microcomputer by detecting an off signal output from the microcomputer, and a means for inputting the armature current according to an interrupt program activated by the interrupt pulse at the time of turning on, Interrupt program started by the above interrupt pulse when off And a means for calculating an average value of the armature current from the current value input by the interrupt program at the time of turning on and the time of turning off at the time of turning off. Car controller. 2. A chopper circuit for applying a voltage from a battery to an electric motor, operating states of the battery, the electric motor, the chopper circuit, and an accelerator pedal and an armature current of the electric motor are detected to determine a chopper conduction ratio. In a control device for an electric vehicle having a microcomputer that outputs a signal for calculating and turning on and off the chopper circuit, a means for detecting the voltage across the chopper circuit, and when the voltage of the chopper circuit falls. Means for generating an interrupt pulse to the microcomputer, means for generating an interrupt pulse to the microcomputer when the voltage of the chopper circuit rises, and interrupts activated by the interrupt pulse at the voltage falling of the chopper circuit Means for inputting the armature current according to a program,
Means for inputting the armature current according to an interrupt program activated by an interrupt pulse at the rising of the chopper circuit voltage, and the armature from the current value input by the interrupt program at the falling and rising of the chopper circuit voltage A control device for an electric vehicle, comprising: means for calculating an average value of electric current.