JP6500296B2 - Traveling control device and industrial vehicle - Google Patents

Description

  The present invention relates to a travel control device and an industrial vehicle provided with the travel control device.

  As an industrial vehicle provided with a traveling control device, for example, a forklift described in Patent Document 1 is known. In the forklift described in Patent Document 1, the traveling control device calculates a target rotation speed (target speed) which is a target value of the rotation speed of the traveling motor from the tilt angle of the accelerator lever. Then, the traveling control device performs PI control based on the target rotational speed and the current rotational speed (current speed) of the traveling motor, and outputs a control signal (torque command) to the traveling motor for traveling. The current rotational speed (current speed) of the motor is matched with the target rotational speed (target speed).

JP 2012-90463 A

  In the conventional forklift including the above-mentioned forklift, in general, acceleration control is performed on a flat road as traveling control, automatic torque is increased on an uphill road, and neutral regeneration and downhill regeneration are also performed. There was a problem. Moreover, when PI control is performed like the said forklift, since travel speed hardly changes with the weight of load, there existed a problem that operation feeling was not good.

  This invention is made in view of the said situation, Comprising: The place made into the subject is providing the traveling control apparatus which can simplify control, and the industrial vehicle provided with the said traveling control apparatus. .

In order to solve the above-mentioned subject, the traveling control device concerning one embodiment of the present invention,
It is a travel control device of an industrial vehicle, and
A lever movement amount calculation unit configured to calculate a lever movement amount defined so as to have a non-linear relationship with the inclination angle from the inclination angle of the accelerator lever of the industrial vehicle and have a larger change amount as the inclination angle is larger;
An instruction rotation number calculation unit configured to calculate an instruction rotation number of a traveling motor of the industrial vehicle having a linear relationship with the lever movement amount from the lever movement amount;
A target rotation number calculation unit that calculates a target rotation number of the traveling motor based on the designated rotation number at a predetermined cycle;
The motor control unit performs P control, PI control or PID control with the current rotation number of the traveling motor and the target rotation number, and controls the traveling motor.
The target rotational speed calculation unit
The lamp processing equivalent to the degree of changing the target rotational speed is performed by calculating the deviation between the target rotational speed and the instructed rotational speed, and performing the lamp processing to gradually bring the target rotational speed closer to the instructed rotational speed. The target rotational speed is calculated while changing the gain of the variable according to the deviation.

The target rotational speed calculation unit
The deviation is compared with a plurality of threshold values set in advance, and the gain is changed according to the result of the comparison so that the gain decreases as the target number of rotations approaches the designated number of rotations. preferable.

Moreover, in order to solve the said subject, the industrial vehicle which concerns on this invention,
One of the above-described travel control devices is provided.

  According to the present invention, it is possible to provide a travel control device capable of simplifying control and an industrial vehicle provided with the travel control device.

It is a block diagram of the industrial vehicle (forklift truck) which concerns on 1st Embodiment of this invention. It is a block diagram of a traveling control device concerning a 1st embodiment of the present invention. It is a figure which shows the relationship between the tilting angle of an accelerator lever, and a lever movement amount. It is a figure which shows the relationship between lever movement amount and instruction | command rotation speed. It is a figure which shows an example of magnitude correlation of instruction | command rotation speed, vehicle speed 0 point, target rotation speed, and present rotation speed. It is a block diagram of the traveling control device concerning a 2nd embodiment of the present invention. It is a flowchart regarding control of a traveling control device. It is a figure for demonstrating the gain of lamp processing.

  Hereinafter, with reference to an accompanying drawing, an embodiment of a traveling control device concerning the present invention and an industrial vehicle provided with the traveling control device concerned is described. In the following, a reach type forklift will be described as an example of an industrial vehicle.

First Embodiment
FIG. 1 shows a reach type forklift (hereinafter, forklift) 100 according to a first embodiment of the present invention. The forklift 100 includes the travel control device 10 according to the first embodiment of the present invention inside the vehicle body 1.

  The forklift 100 includes a pair of left and right straddle legs 2 extended to the front side of the vehicle body 1, a carriage 3 moving in the front and rear direction along the straddle legs 2, and a pair of left and right mast devices 4 erected on the carriage 3. A pair of left and right forks 5 vertically movably attached to the mast device 4, a pair of left and right front wheels 6 provided on the straddle leg 2, and a caster provided on the right rear of the vehicle body 1 (under the driver's seat 7) And a ring (not shown).

  The forklift 100 includes a driving wheel 20 and a traveling motor 21 at the left rear of the vehicle body 1. When the traveling motor 21 is rotationally driven under the control of the traveling control device 10, the power of the traveling motor 21 is transmitted to the drive wheel 20, and the drive wheel 20 rotates forward or reversely. Furthermore, the forklift 100 includes a steering handle 8 for steering the drive wheels 20 and a lever 9 on the top surface of the vehicle body 1. The levers 9 include a cargo handling lever (lift lever, tilt lever and reach lever) and an accelerator lever.

  When an accelerator ON operation is performed that causes the accelerator lever in the neutral position to lean forward or backward, the travel control device 10 causes the drive wheel 20 to rotate normally in the case of forward lean and reverse the drive wheel 20 in the case of backward lean. . The travel control device 10 changes the rotation direction of the drive wheel 20 when an accelerator reverse operation is performed such that the accelerator lever in the forward tilt state is tilted backward or the accelerator lever in the backward tilt state is tilted forward. The travel control device 10 stops the rotation of the drive wheel 20 when an accelerator OFF operation is performed to return the accelerator lever in the forward or backward tilt state to the neutral position.

  The specific configuration of the traveling control device 10 is shown in FIG. The travel control device 10 includes a lever movement amount calculation unit 11, a command rotation number calculation unit 12, a target rotation number calculation unit 13, a lamp gain determination unit 14, and a motor control unit 15. The travel control device 10 is configured of, for example, at least one microcomputer. The lamp gain determination unit 14 may be included in the target rotation speed calculation unit 13 (for example, the target rotation speed calculation unit 13 may have the function of the lamp gain determination unit 14).

  The lever movement amount calculation unit 11 calculates the lever movement amount from the tilt angle of the accelerator lever. The tilt angle of the accelerator lever is input from tilt angle detection means (for example, a potentiometer) provided on the accelerator lever. The lever movement amount has a non-linear relationship with the tilt angle. Specifically, as shown in FIG. 3, the larger the tilt angle, the larger the lever travel (the lever travel also maximizes when the tilt angle is maximum), but the larger the tilt angle, the more the lever travel changes As the amount increases, and the tilt angle decreases, the amount of change in lever movement decreases. For this reason, high-speed traveling can be easily performed in the range in which the falling angle is large, and low-speed traveling can be easily performed in the range in which the falling angle is small. As a result, the operation feeling is improved.

  The commanded rotation number calculation unit 12 calculates a commanded rotation number that is a command value of the rotation number of the traveling motor 21 from the lever movement amount. As shown in FIG. 4, the designated rotation number has a linear relationship with the lever movement amount. For this reason, the designated rotation number calculation unit 12 can calculate the designated rotation number by multiplying the lever movement amount by a predetermined coefficient. The calculated instruction rotation number is output to the target rotation number calculation unit 13.

  The target rotation speed calculation unit 13 calculates a target rotation speed that is a target value of the rotation speed of the traveling motor 21 based on the instructed rotation speed at a predetermined cycle (for example, 2 [ms]). Specifically, the target rotation speed calculation unit 13 performs a ramp process to make the target rotation speed approach the indicated rotation speed in stages, and calculates the target rotation speed. The target rotational speed is a value less than the instructed rotational speed when the instructed rotational speed is positive (normal rotation), and the target rotational speed is a value greater than the instructed rotational speed when the instructed rotation speed is negative (reverse rotation) .

  The gain of the ramp processing corresponds to the degree to which the target rotational speed is changed in the ramp processing. In the present embodiment, the lamp gain determination unit 14 can change the gain of the lamp processing into three stages of large, medium, small, and small. When the gain is increased, the degree of changing (increasing or decreasing) the target rotational speed also increases, so the time for the target rotational speed to reach the designated rotational speed becomes short. That is, the time until the current rotation number (current rotation number) of the traveling motor 21 reaches the designated rotation number becomes short. On the other hand, when the gain is reduced, the degree of changing the target rotational speed is also reduced, and therefore, the time until the target rotational speed reaches the designated rotational speed becomes longer. That is, the time until the current rotational speed reaches the designated rotational speed becomes long.

  The lamp gain determination unit 14 determines the magnitude relationship between the instructed rotation speed, the target rotation speed, and the zero vehicle speed at a predetermined cycle (for example, 2 ms), and from the result, the gain of the lamp processing is determined by the first gain The gain is determined to be (medium gain), a second gain (small gain) smaller than the first gain, or a third gain (large gain) larger than the first gain. Here, the zero vehicle speed means the number of rotations of the traveling motor 21 when the speed of the forklift 100 is zero, and the number of rotations is zero.

  In the case of vehicle speed 0 point <target rotation speed <instructed rotation speed, or in the case of vehicle speed 0 point> target rotation speed> instructed rotation speed, in other words, when forklift 100 is in an acceleration state (for example, the tilt angle of the accelerator lever is increased In the case, the lamp gain determination unit 14 determines the gain as the first gain (in the middle of gain).

  In the case of vehicle speed 0 point <instructed rotation speed <target rotation speed, or in case of vehicle speed 0 point> instructed rotation speed> target rotation speed, in other words, when forklift 100 is in a decelerating state (e.g. Case), the lamp gain determination unit 14 determines the gain as the second gain (small gain).

  In the case of instructed rotation speed <vehicle speed 0 point <target rotation speed, or instructed rotation speed> vehicle speed 0 point> target rotation speed (in the case of FIG. 5), in other words, when forklift 100 is in reverse The lamp gain determination unit 14 determines the gain to be the third gain (gain is large) when the accelerator lever in the state is made to lean backward or when the accelerator lever in the backward lean state is made to lean forward).

  As described above, since the lamp gain determination unit 14 changes the gain of the lamp processing according to the magnitude relationship between the instructed rotation speed, the target rotation speed, and the zero vehicle speed, a plurality of travel control is used properly as in the conventional forklift For example, acceleration is limited on a flat road, automatic torque is increased on an uphill road, and it is not necessary to perform neutral regeneration, downhill regeneration, and the like. Therefore, according to travel control device 10 and forklift 100 concerning this embodiment, control can be simplified.

  The motor control unit 15 controls the traveling motor 21 in accordance with the target rotational speed. Specifically, the motor control unit 15 performs P control (proportional control) based on the target rotation speed and the current rotation speed (current rotation speed) of the traveling motor 21, and transmits a control signal ( Output the torque command). The current rotation number of the traveling motor 21 is input from, for example, an encoder provided to the traveling motor 21.

  By performing P control as described above, if the load on the fork 5 is heavy, the time to reach the target rotation speed (target speed) will be longer, and if the load on the fork 5 is lighter, the target rotation speed (target speed The time to reach) is shortened. Therefore, according to travel control device 10 and forklift 100 concerning this embodiment, operation feeling improves.

Second Embodiment
Next, a travel control device 10A according to a second embodiment of the present invention will be described with reference to FIG. The travel control device 10A is in common with the travel control device 10 according to the first embodiment except that the travel control device 10A includes the target rotation speed calculation unit 13A.

  The target rotation speed calculation unit 13A calculates a target rotation speed that is a target value of the rotation speed of the traveling motor 21 based on the instructed rotation speed at a predetermined cycle (for example, 2 [ms]). Specifically, the target rotation number calculation unit 13A performs ramp processing to bring the target rotation number closer to the designated rotation number in stages, and changes the gain of the ramp processing according to the deviation between the target rotation number and the designated rotation number. While calculating the target number of revolutions. If the absolute value of the deviation between the target rotational speed and the designated rotational speed is large, the gain is large, and if the absolute value of the deviation is small, the gain is small.

  FIG. 7 shows a flowchart regarding control of the traveling control device 10A. Hereinafter, it is assumed that the forklift 100 of FIG. 1 is provided with the travel control device 10A. Further, the target rotation speed [rpm] is set as the target speed, and the designated rotation speed [rpm] is set as the designated speed.

  The traveling control device 10A starts control for calculating the target speed at a predetermined cycle (for example, 2 [ms]). In step S 1, when the angle (tilt angle) of the accelerator lever is input to the lever movement amount calculation unit 11, the lever movement amount calculation unit 11 calculates the lever movement amount and outputs it to the commanded rotation number calculation unit 12.

  In step S2, the instruction rotation number calculation unit 12 calculates an instruction speed from the lever movement amount. In step S3, the target rotation speed calculation unit 13A determines whether the brake is on (for example, the brake pedal is depressed).

  When the brake is not on (for example, the brake pedal is not depressed), in step S4, the target rotation speed calculation unit 13A calculates the deviation between the target speed and the instructed speed. In the present embodiment, the deviation = designated speed−target speed. When the forklift 100 is started (when the accelerator ON operation is performed to tilt the accelerator lever forward or backward in the stopped forklift 100), the target speed in step S4 is zero. That is, the deviation is equal to the designated speed. On the other hand, after the forklift 100 is started, the target speed in step S4 is the target speed calculated immediately before.

  The target rotation speed calculation unit 13A compares the deviation with a plurality of preset threshold values, and determines the gain according to the comparison result (steps S5 to S12). In this embodiment, the maximum value of the instruction speed is 3000 [rpm], and the minimum value is -3000 [rpm].

  First, the target rotation speed calculation unit 13A compares the deviation with 0, and raises the target speed by one step (for example, +1 [rpm]) if the deviation> 0 (step S5). Next, the target rotation speed calculation unit 13A compares the deviation with 1000 [rpm], and raises the target speed by one step (for example, +1 [rpm]) if deviation> 1000 [rpm] (step S6) ). Next, the target rotation speed calculation unit 13A compares the deviation with 2000 [rpm], and raises the target speed by one step (for example, +1 [rpm]) if deviation> 2000 [rpm] (step S7). ). Next, the target rotation speed calculation unit 13A compares the deviation with 3000 [rpm], and raises the target speed by one step (for example, +1 [rpm]) when deviation> 3000 [rpm] (step S8). ).

  Next, the target rotation speed calculation unit 13A compares the deviation with 0, and reduces the target speed by one step (for example, −1 [rpm]) if the deviation is <0 (step S9). Next, the target rotation speed calculation unit 13A compares the deviation with -1000 [rpm], and reduces the target speed by one step (for example, -1 [rpm]) if deviation <-1000 [rpm]. (Step S10). Next, the target rotation speed calculation unit 13A compares the deviation with -2000 [rpm], and reduces the target speed by one step (for example, -1 [rpm]) when deviation <-2000 [rpm]. (Step S11). Next, the target rotation speed calculation unit 13A compares the deviation with -3000 [rpm], and reduces the target speed by one step (for example, -1 [rpm]) when deviation <-3000 [rpm]. (Step S12).

  After all, in the present embodiment, the target rotation speed calculation unit 13A can change the gain of the ramp processing to four stages. In the case of -1000 [rpm] 偏差 deviation 1000 1000 [rpm], the target speed is increased or decreased by one step (or increased or decreased by 1 [rpm]) as a first gain. When 1000 [rpm] <deviation ≦ 2000 [rpm] or −2000 [rpm] ≦ deviation <−1000 [rpm], the target speed is increased or decreased by 2 stages (2 [rpm] increase or decrease) second It becomes a gain. If 2000 [rpm] <deviation <3000 [rpm] or-3000 [rpm] <deviation <-2000 [rpm], increase or decrease the target speed by 3 steps (increase or decrease 3 [rpm]) Third It becomes a gain. When the deviation> 3000 [rpm] or the deviation <-3000 [rpm], the target speed is increased or decreased by four steps (or increased or decreased by 4 [rpm]).

  In step S13, the motor control unit 15 performs P control with the target speed calculated by the target rotation speed calculation unit 13A and the input speed (current rotation speed) input from the encoder provided in the traveling motor 21. Calculate the torque. Then, the motor control unit 15 outputs a control signal (torque command) to the traveling motor 21.

  FIG. 8A shows a change in gain of lamp processing when the indicated speed is 3000 [rpm] and the initial target speed is -3000 [rpm]. Since the deviation> 3000 [rpm] until the target speed becomes 0, the gain becomes the fourth gain that increases the target speed by 4 steps (increases 4 [rpm]). Thereafter, as the target speed approaches the commanded speed, the gain changes with the third gain, the second gain, and the first gain.

  FIG. 8B shows a change in gain of lamp processing when the designated speed is -3000 [rpm] and the initial target speed is 3000 [rpm]. Since the deviation is less than -3000 rpm until the target velocity reaches 0, the gain becomes the fourth gain that reduces the target velocity by 4 steps (decreases 4 rpm). Thereafter, as the target speed approaches the commanded speed, the gain changes with the third gain, the second gain, and the first gain.

  FIG. 8C shows a change in gain of lamp processing when the indicated speed is 2000 [rpm] and the initial target speed is -2000 [rpm]. Since the deviation> 3000 [rpm] until the target speed reaches -1000 [rpm], the gain becomes the fourth gain that causes the target speed to be increased by 4 steps (increased by 4 [rpm]). Thereafter, as the target speed approaches the commanded speed, the gain changes with the third gain, the second gain, and the first gain.

  Referring again to FIG. 7, when the brake is on (for example, the brake pedal is depressed), the target rotation speed calculation unit 13A compares the target speed with a predetermined threshold in steps S14 and S16. The predetermined threshold is an increase / decrease value (for example, +4 [rpm] or -4 [rpm]) of the target speed at the maximum gain (fourth gain).

  In step S14, in the case of target speed> threshold value (+4 [rpm]), in step S15, the target rotation speed calculation unit 13A reduces the target speed by 4 steps (decreases 4 [rpm]). In step S16, in the case of target speed <threshold (-4 [rpm]), in step S17, the target rotation speed calculation unit 13A increases the target speed by 4 steps (increases 4 [rpm]). If NO at steps S14 and S16 (if -4 [rpm] 目標 target speed + +4 [rpm]), then at step S18, the target rotation speed calculation unit 13A sets the target speed to zero. Next, the process proceeds to step S13.

  As described above, the target rotation speed calculation unit 13A calculates the target rotation speed while changing the gain of the ramp processing according to the deviation between the target rotation speed (target speed) and the command rotation speed (command speed). Therefore, the traveling control device 10A does not need to use a plurality of traveling control (for example, acceleration is limited on a flat road, automatic torque is increased on an uphill road, and neutral regeneration and downhill regeneration are also performed). Therefore, according to the travel control device 10A according to the present embodiment, control can be simplified.

  The embodiments of the travel control device and the industrial vehicle according to the present invention have been described above, but the present invention is not limited to the above embodiments.

In the first embodiment, the lamp gain determination unit 14
(1) In the case of vehicle speed 0 point <target rotation speed <designated rotation speed, or in the case of vehicle speed 0 point> target rotation speed> designated rotation speed, the gain is determined to be the first gain (medium gain),
(2) If the vehicle speed 0 point <instructed rotation speed <target rotation speed, or if the vehicle speed 0 point> instructed rotation speed> target rotation speed, determine the gain as the second gain (small gain),
(3) The gain is determined to be the third gain (gain is large) in the case of the instructed rotation speed <vehicle speed 0 point <target rotation speed, or in the case of the instructed rotation speed> vehicle speed 0 point> target rotation speed.
The present invention is not limited to this, and the method of determining the gain can be arbitrarily changed as long as it is based on the magnitude relationship between the instructed rotation number, the target rotation number, and the zero vehicle speed.

  In the second embodiment, although the target rotation speed calculation unit 13A changes the gain of the lamp processing into four stages according to the deviation between the target rotation speed (target speed) and the command rotation speed (command speed), It may be changed to three or less stages, or may be changed to five or more stages. Further, the degree of changing the target rotational speed can also be changed as appropriate. For example, the increase / decrease value of the target speed when one step is changed may be 2 [rpm].

  Although it is preferable that the motor control unit 15 perform P control, in the present invention, the operation feeling is improved to some extent by calculating the instruction rotation number from the lever movement amount having a non-linear relationship with the tilt angle of the accelerator lever. The control unit 15 may perform control other than P control, for example, PI control or PID control.

  Industrial vehicles according to the present invention include forklifts other than reach forklifts, and cargo handling vehicles other than forklifts.

Reference Signs List 1 vehicle body 2 straddle leg 3 carriage 4 mast device 5 fork 6 front wheel 7 driver's seat 8 steering wheel 9 lever 10, 10A travel control device 11 lever movement amount calculation unit 12 commanded rotation number calculation unit 13, 13A target rotation number calculation unit 14 Ramp Gain Determination Unit 15 Motor Control Unit 20 Drive Wheels 21 Drive Motor 100 Forklift

Claims (3)

It is a travel control device of an industrial vehicle, and
A lever movement amount calculation unit configured to calculate a lever movement amount defined so as to have a non-linear relationship with the inclination angle from the inclination angle of the accelerator lever of the industrial vehicle and have a larger change amount as the inclination angle is larger;
An instruction rotation number calculation unit configured to calculate an instruction rotation number of a traveling motor of the industrial vehicle having a linear relationship with the lever movement amount from the lever movement amount;
A target rotation number calculation unit that calculates a target rotation number of the traveling motor based on the designated rotation number at a predetermined cycle;
The motor control unit performs P control, PI control or PID control with the current rotation number of the traveling motor and the target rotation number, and controls the traveling motor.
The target rotational speed calculation unit
The lamp processing equivalent to the degree of changing the target rotational speed is performed by calculating the deviation between the target rotational speed and the instructed rotational speed, and performing the lamp processing to gradually bring the target rotational speed closer to the instructed rotational speed. A travel control device, wherein the target number of revolutions is calculated while changing the gain of according to the deviation. The target rotational speed calculation unit
The deviation is compared with a plurality of threshold values set in advance, and the gain is changed according to the result of the comparison so that the gain decreases as the target number of rotations approaches the designated number of rotations. The travel control device according to claim 1, characterized in that: An industrial vehicle comprising the travel control device according to claim 1.

Images