WO2008041395A1

WO2008041395A1 - Motor controller

Info

Publication number: WO2008041395A1
Application number: PCT/JP2007/062232
Authority: WO
Inventors: Hideaki Yoshimatsu
Original assignee: Hy Incorporated
Priority date: 2006-10-03
Filing date: 2007-06-18
Publication date: 2008-04-10
Also published as: JP4294086B2; JPWO2008041395A1

Abstract

An algorithm for increasing a powering torque outputted when a target torque To is outputted in the same direction as the operating direction as the controlled variable X of an operating lever (2) increases and for decreasing the powering torque as the rotational speed N of a motor (1) increases even if the controlled variable X is constant is built in an operation algorithm (3b) prestored in a controller (3) so that control characteristics similar to control of bleed off pressure in a hydraulic drive system are imparted. Consequently, an operator can control to a target operational speed easily, and operability and operation sense similar to those in a hydraulic drive system can be attained through control based on a simple algorithm.

Description

Specification

Motor control device

Technical field

[0001] The present invention relates to a control device for a motor that controls output torque of a motor that operates an inertial body based on an operation of an operation end.

Background art

[0002] A hydraulic pump or a hydraulic motor is used as a drive device for operating an inertial body having a large inertial mass such as a construction machine, including a turning operation of a hydraulic shovel and a hydraulic crane and a traveling operation of a wheel loader. Many hydraulic drives have been adopted. In recent years, in order to squeeze away hydraulic energy with a control valve, an electric drive system using an electric motor with less energy loss is being adopted instead of the hydraulic drive system using a hydraulic drive system with a large energy loss. The electric drive system also has the advantage of using the motor as a generator when decelerating the inertia body and regenerating braking energy for deceleration.

[0003] A hydraulic drive system using a conventional hydraulic drive system is characterized in that the operator operates an operating end such as a lever or a pedal to control the operation of the inertial body, which is a human operation sense. The motorized drive system using a motor can not realize the operability and sense of operation like a hydraulic drive system, while the operator operates it. The problem is happening!

That is, in the hydraulic drive system, by controlling the opening area of the bleed-off control throttle of the spool valve and the meter-out control throttle by the operation of the operation end, the operation amount of the operation end and the rotation speed of the hydraulic motor are obtained. Accordingly, the output torque is controlled and acceleration, deceleration and stop of the inertia body are performed smoothly. However, in the case of the electric drive system, when the rotational speed of the motor is controlled, the speed control is performed with the output torque as the maximum value. As a result, the acceleration and deceleration of the inertial body become steep, and the smooth operability as in the hydraulic drive system can not be obtained, and there is a problem that the operator's sense of operation is far from the hydraulic drive system.

In order to solve such problems, research and development has been advanced to bring the operability and sense of operation when operating an inertial body such as a construction machine by an electric drive system closer to that of a hydraulic drive system. Several methods have been proposed to control the output torque of the motor based on the operation of the operating end so as to bring the operability and sense of operation closer to those of the hydraulic drive system (see, for example, Patent Document 13) ).

In the turning control device of the electric drive system described in Patent Document 1, when the operation amount of the operating end is at or near the maximum, the maximum acceleration torque (curling torque) is output, and the operation amount is zero. The maximum braking torque (regenerative torque) is output near zero, and as in the hydraulic drive system, the inertia body is smoothly stopped at the neutral position of the operation end, and the turning speed of the inertia body is detected. A swing speed sensor is provided to determine the deviation between the preset swing speed and the actual swing speed according to the amount of operation of the operating end, and to give an acceleration torque or a braking torque according to this deviation. Thus, during the transition period of acceleration and deceleration of turning, torque control characteristics according to the amount manipulated by the operator can be obtained.

In the drive apparatus for a construction machine described in Patent Document 2, the first target torque is calculated based on a predetermined functional relationship with respect to the operation amount of the operation end, and the operation amount of the operation end is calculated. A target speed of the motor is calculated based on a predetermined functional relation, and a second target torque is calculated based on a predetermined functional relation for the speed deviation between the target speed and the actual speed of the motor. The output torque of the motor is controlled with the target torque having the smaller absolute value among the first and second target torques as the target value. That is, in the case of the acceleration operation in which the speed deviation between the target speed and the actual speed of the motor becomes large, for example, the first target torque calculated based on the operation amount of the operator is With the target torque of 2) as the target value and the speed of the motor increases and the speed deviation becomes smaller, the second target torque (the first target torque) calculated based on the speed deviation is used as the target. By using these values, as in the case described in Patent Document 1, torque control characteristics as the operator's operation amount can be obtained during the transition period of acceleration and the like. In the case described in Patent Document 2, the allowable maximum torque calculated based on a predetermined functional relationship with the actual speed of the motor is set as a third target torque, and the first and second target torques are set as the first target torque. It is also proposed to set the one with the smallest absolute value among these target torques, including the target torque of 3, as the target torque, and to prevent the overload of the motor.

[0008] Further, in the device described in Patent Document 3, the hydraulic pressure is controlled in a controller that controls the motor. By incorporating an emulation model that simulates the dynamic characteristics of the drive device in real time, the control target value is calculated by the emulation model according to the operation of the control terminal, and the motor is controlled, Ru.

Patent Document 1: Japanese Patent Application Laid-Open No. 2001-10783

Patent Document 2: Japanese Patent Application Laid-Open No. 2003-33063

Patent Document 3: Japanese Patent Application Laid-Open No. 2003-333876

Disclosure of the invention

Problem that invention tries to solve

According to Patent Document 1, the motor can be controlled by a simple algorithm of limiting the maximum output torque of the motor and commanding the acceleration torque or the braking torque according to the deviation of the turning speed. As described later, in the hydraulic drive, by controlling the opening area of the bleed-off control throttle of the spool valve by the operation of the operation end, a function of the bleed-off opening area and the bleed-off flow rate (= pump flow rate motor flow rate) As the bleed-off pressure and the meter-out pressure are pressure-controlled, the control characteristics of the hydraulic drive are different, and the operability and sense of operation are different from those of the hydraulic drive system.

According to Patent Document 2, a target torque having a smaller absolute value among a first target torque based on an operation amount and a second target torque based on a speed deviation of a motor is set as a target value. Although it is described that the output torque of the motor is controlled and the expression is different, basically, the torque control based on the speed deviation is performed by adding a maximum value limit to the torque output with respect to the manipulated variable. The same technique as described in US Pat. No. 5,677,859, in which the smaller of the torques that are performed and consequently both forces are also calculated is selected. Therefore, the control described in Patent Document 2 also differs from the control characteristic of the hydraulic drive system, and the operability and operational feeling thereof are different from those of the hydraulic drive system.

On the other hand, the technique described in Patent Document 3 needs to calculate an emulation model of a complicated algorithm in real time, which can bring the operability and sense of operation much closer to those of the hydraulic drive system. Because of this, the control model is complicated, long and requires computation time, and the response time of the control is long, and there is a problem that fine control can not be performed. It also has a very high performance to incorporate emulation models of complex algorithms There is also a problem that requires a controller.

Therefore, an object of the present invention is to provide a control device of a motor that can obtain the same operability and sense of operation as a hydraulic drive system by control based on a simple algorithm. Means to solve the problem

In order to solve the above-mentioned problems, the present invention controls the rotational drive of a motor for operating an inertial body by at least the operation of an operating end for varying the operating amount, and detects the operating amount of the operating end. Based on the operation detection means, the rotation detection means for detecting the rotation direction and the rotation speed of the electric motor, and the detection values of the operation detection means and the rotation detection means, the target torque to be borne by the motor is calculated. The motor control means controls the output torque of the electric motor to the direction and the magnitude of the target torque, and the output torque corresponds to a fly torque as the electric motor function of the electric motor and a regenerative torque as the electric generator function. In the control device for the motor according to the present invention, when the absolute value of the amount of operation of the operating end increases, the amount of operation of the operation end of the operating end is constant. And it employs a configuration that incorporates the algorithms absolute value of the rotational speed is reduced becomes larger of the electric motor.

[0015] That is, in the calculation means for calculating the target torque, the torque to be applied increases as the absolute value of the operation amount at the operation end increases, and the rotational speed of the motor is increased even if the operation amount at the operation end is constant. By incorporating an algorithm that decreases as the absolute value of the degree increases, as described below, the control characteristic similar to the bleed-off pressure control in the hydraulic drive system is provided, and the operating speed targeted by the operator is set. We made it easy to control and made it possible to obtain the same operability and feel as the hydraulic drive system by control based on a simple algorithm.

As shown in FIG. 7, in the hydraulic drive system in which the hydraulic motor 52 is driven by the hydraulic pump 52 by operating the spool valve 51, the meter-in pressure P and the meter-out pressure P of the hydraulic motor 53 are effective. The differential pressure is the hydraulic motor torque. If meter-in pressure P is higher, oil

twenty one

Drive pressure for driving the pressure motor 53, hydraulic motor if the meter out pressure P is higher

2

This is the braking pressure for braking 53.

As shown in FIG. 8, when the operation amount at the operation end increases, the opening area of the bleed-off control throttle 51a of the spool valve 51 of the hydraulic drive device decreases, and the bleed-off pressure P becomes high. At the same time, the meter-in pressure P is controlled so that the meter-in pressure P becomes lower and the drive pressure becomes smaller as the rotational speed of the hydraulic motor 53 becomes larger. . Therefore, as the rotational speed of the hydraulic motor 53 increases, the drive pressure gradually decreases, and the inertia of the inertia body is not accelerated at a value commensurate with the drive resistance due to the friction of the drive system or the pressure loss of the hydraulic piping system or the spool valve 51. Is controlled to the target operating speed. Therefore, by incorporating the above algorithm, it is possible to have the same control characteristic as the control of the meter-in pressure P by such a hydraulic drive type bleed-off control throttle 51a.

The meter-in control throttle 51b of the spool valve 51 shown in FIG. 7 controls the meter-in pressure P of the hydraulic motor 53 when the other actuator is operated by the same hydraulic pump 52. The resistance of the driving pressure of the hydraulic motor 53 is intended. The hydraulic driving system has a basic control characteristic in which the driving pressure is controlled by controlling the meter-in pressure P by the bleed-off control throttle 51a.

In the calculation means, the regenerative torque increases as the absolute value of the operation amount at the operating end decreases, and the absolute value of the rotational speed of the motor decreases even if the operation amount at the operating end is constant. By incorporating an algorithm that becomes smaller as it becomes, it is possible to provide control characteristics similar to the control of the hydraulic drive meter pressure, and to obtain the operability and the sense of operation similar to the hydraulic drive.

That is, in the hydraulic drive as shown in FIG. 7, as shown in FIG. 9, the meter out control throttle 51 c of the spool valve 51 starts to open when the operation amount of the operating end also reaches a value with zero force. Therefore, the opening area increases with the increase of the operation amount. If the operating amount is returned to a smaller value in this state, the meter-out pressure P is increased, and the rotational speed of the hydraulic motor 53 is increased with the same operating amount.

2

As the degree decreases, the meter-out pressure P is controlled to be lower. Therefore, the hydraulic

2

If the amount of operation at the operating end is returned from a certain rotational speed of the motor 53, the braking pressure decreases as the braking pressure increases when the rotational speed increases, and the braking pressure and friction of the drive system become less At the value corresponding to, the deceleration of the inertial body is lost and the operator is controlled to the target operating speed. Therefore, by incorporating the above algorithm, the control characteristic similar to that of the control of the meter-out pressure P of such a hydraulic drive system can be obtained. He is happy.

[0021] In the case where the operating end has the operating direction variable in both plus and minus directions in addition to the operating amount, and the motor is driven to rotate in both plus and minus directions, the operation detecting means is the operating amount of the operating end. The operation direction of the operation end is detected in the neutral range including zero, or the operation direction of the operation end and the rotation direction of the electric motor are opposite to each other. At the same time, by incorporating an algorithm that sets the torque to zero and the regenerative torque to the maximum value, the motor is rotated in one direction by the operation of the pedal as the operation end like the wheel loader travel control. It also applies to the one that drives the motor to rotate in both positive and negative directions by the operation of the lever as the operation end, such as the swing control of a shovel or a crane, which is only by itself. Similarly to the hydraulic drive system, when the operation amount of the operation end is in the neutral range, the neutral brake function for stopping and holding is given, and the operation direction of the operation end is reverse to the rotation direction of the motor. In this case, the inertia body is decelerated and stopped with a large braking torque, for example, when the parking brake is released when the inertia body is advanced on a slope or the inertia body is turned upward on a slope, Can be prevented. When the inertial body stops and the motor itself also stops, the motor outputs a driving torque according to the amount of operation in the reverse direction of the operating end to accelerate the inertial body in the reverse rotation direction.

That is, in the hydraulic drive as shown in FIG. 7, when the spool valve 51 is neutral, the motor control block 5 lb and the meter out control throttle 51 c are fully closed to block the motor port. 53 is stopped and held in a so-called neutral state, and the operating end may be operated in the direction opposite to the rotational direction of the hydraulic motor 53 while turning the inertia body to increase the braking pressure for deceleration. At this time, the hydraulic motor 53 brakes the inertia body at the maximum pressure by a brake valve (not shown), and when the inertia body stops and the hydraulic motor itself stops, the drive according to the operation amount in the reverse direction of the operation end The pressure is output to accelerate the inertial body in the reverse rotation direction.

[0023] In the case where the operating end has the operating direction variable in both plus and minus directions in addition to the operating amount, and the motor is driven to rotate in both plus and minus directions, the operation detecting means is used as the operating amount of the operating end. And positive or negative operation direction shall be detected. In the calculation means, when the operation amount of the operating end is in the neutral range including zero, or when the operating direction of the operating end and the rotational direction of the motor are in opposite directions, the absolute value of the rotational speed of the motor is zero. By incorporating an algorithm that increases the absolute value of the regenerative torque in accordance with the absolute value of the rotational speed of the motor in a small range in the vicinity, the inertial body can be slope-started or the inertial body is turned upward on a slope At the same time, it is possible to smoothly carry out slope start and upward turn by suppressing the downward and backward movement and downward turning of the inertial body.

That is, on slopes and slopes, load torque applied to the hydraulic motor causes internal leakage of the hydraulic motor and so-called slip rotation occurs. This slip rotation is a minute value, and its rotation speed increases with the pressure of the hydraulic motor. For this reason, when making the inertial body start on a slope or turn upward in the hydraulic drive system, the hydraulic motor torque by the hydraulic motor drive pressure is smaller than the load torque by the inclination. Reverse check in the descent direction of the hydraulic motor is suppressed by the load check valve 51d, and when the hydraulic motor torque by the driving pressure becomes larger than the load torque by the inclination, the slope start and upward turning starts smoothly. Ru.

On the other hand, in the conventional electric drive system, as shown in FIG. 10, when the output torque of the motor is smaller than the load torque due to the inclination, the maximum torque is obtained if the motor reverses even in the downward direction. When the output torque becomes larger than the load torque, it will be in the critical state. For this reason, the movement of the motor when the absolute value of the rotational speed is near zero becomes vibrational, and it is not possible to smoothly start a slope or turn upward. Therefore, as shown in FIG. 6 later, an algorithm for increasing the absolute value of the regenerative torque in accordance with the magnitude of the absolute value of the rotational speed of the motor within a small range where the absolute value of the rotational speed of the motor is near zero. By taking in the motor, it is possible to switch the motor from regeneration to power when the output torque becomes larger than the load torque, and to perform slope start and upward turning smoothly as in the hydraulic drive system.

The calculation means is divided into a drive torque for driving the inertial body by the electric motor and a driven torque for driving the electric motor by the inertial body using an arithmetic algorithm stored in advance. Also calculated as the sum of the drive torque and the driven torque In this arithmetic algorithm, the absolute value of the driving torque increases as the absolute value of the operating amount of the operating end increases, and the absolute value of the rotational speed of the motor is increased even if the operating amount of the operating end is constant. The driving torque calculation algorithm decreases as the value increases, and the absolute value of the driven torque increases as the absolute value of the operating amount of the operating end decreases, and the operating amount of the operating end is constant even if the operating amount of the operating end is constant. Among the driven torque calculation algorithms that become smaller as the absolute value of the rotational speed of the motor becomes smaller, at least the drive torque calculation algorithm is incorporated to control design of the output torque of the motor. It can carry out similarly to the case of control of motor torque. Therefore, design and adjustment of motor torque characteristics can be easily performed based on conventional knowledge. That is, the hydraulic motor torque is controlled by the effective differential pressure between the meter-in pressure by the bleed-off control throttle and the meter-out pressure by the metering control throttle. The characteristics of the bleed-off control throttle and the meter-out control throttle are independent. It is possible to design, and the control characteristic of the motor torque is determined as the sum of the two characteristics (difference as calculation of pressure). In the case of motor output torque control, too, the drive torque is designed against the meter-in pressure by the bleed-off control throttle of the hydraulic motor, and the drive torque is designed against the meter-out pressure by the meter-out control throttle. The target torque can be designed as the sum of both characteristics.

An arithmetic operation of resistance torque for reducing the target torque is added to the arithmetic algorithm, and the absolute value of the resistance torque becomes larger as the absolute value of the rotational speed of the motor increases. In addition to the resistance of the mechanical drive system, the resistance torque equivalent to the pressure loss in the hydraulic drive system can be obtained by incorporating one or both of the algorithm to reduce and the algorithm to increase the absolute value of the driven torque. By adding elements to the control system, the point at which the motor's actual output torque and load torque are balanced becomes more stable, and stable control can be performed to achieve the operator's intended target speed. The pressure loss in the hydraulic drive system is an energy loss. This resistance torque is a hypothetical one, so it does not become an energy loss!

That is, in the hydraulic drive system as shown in FIG. 7, the pressure loss of the piping system from the hydraulic pump 52 to the hydraulic motor 53, the meter-in control diaphragm 5 lb of the spool valve 51, and the meter-out control There is a pressure loss due to the throttle 51c. These pressure losses increase in proportion to the square of the flow rate as the flow rate of the discharged oil from the hydraulic pump 52 increases, and due to the presence of these pressure losses, the output torque and the load of the hydraulic motor 53 are increased. The point at which the torque balance is stable stabilizes and makes it easy for the operator to achieve the target speed.

[0029] The inertial body operating with each of the above-described motors can be an inertial body that performs turning operation or traveling operation of the construction machine.

Effect of the invention

[0030] In the motor control device of the present invention, the steering torque increases as the absolute value of the operation amount of the operation end increases, and the operation amount of the operation end is constant. Also, by incorporating an algorithm that decreases as the absolute value of the rotational speed of the motor increases, the control characteristic similar to that of bleed-off pressure control in the hydraulic drive system is provided to control the operating speed targeted by the operator. Since it has been made easy, it is possible to obtain the same operability and sense of operation as the hydraulic drive system by control based on a simple algorithm.

In the calculation means, the regenerative torque increases as the absolute value of the operating amount at the operating end decreases, and decreases as the absolute value of the rotational speed of the motor decreases, even if the operating amount at the operating end is constant. By incorporating the above algorithm, the control characteristic similar to that of the hydraulic drive type meter-out pressure control can be obtained, and furthermore, the operability and sense of operation similar to the hydraulic drive type can be obtained.

In addition to the operation amount, in the case where the operation terminal rotates the motor in both directions by changing the operation direction to plus or minus direction in addition to the operation amount, the operation detection means includes the operation amount of the operation end and the plus. It is assumed that a negative operation direction is detected, and when the operation amount of the operation end is in the neutral range including zero, or when the operation direction of the operation end and the rotation direction of the motor are opposite to each other, By incorporating an algorithm that sets the torque to zero and the regenerative torque to the maximum value, such as traveling control of a wheel loader, shovels and cranes can be operated only by rotating the motor in one direction by operating the pedal as the operating end. The invention can be applied to rotation control of the motor in both directions plus and minus by operation of the lever as the operation end, as in the case of turning control of When the operation amount of the work end is in the neutral range, to have a neutral braking function for stopping and holding, Misao operation ends When the direction of movement is opposite to the direction of rotation of the motor, the inertial body is decelerated and stopped with a large braking torque, for example, when the inertial body is started on a slope or the inertial body is turned upward on a slope. In addition, it is possible to prevent the lowering of the inertia body when the parking brake is released.

[0033] In addition to the operation amount, when the operation end has the operation direction variable in both plus and minus directions, and the motor is rotationally driven in both directions, the operation detection means includes the operation amount of the operation end and the plus. It is assumed that a negative operation direction is detected, and when the operation amount of the operation end is in the neutral range including zero, or when the operation direction of the operation end and the rotation direction of the motor are opposite to each other, Incorporating an algorithm that increases the absolute value of the regenerative torque according to the absolute value of the motor's rotational speed within a small range where the absolute value of the motor's rotational speed is near zero, or allows the inertial body to start on a hill When the inertial body is turned upward on a slope, it is possible to smoothly start a slope or turn upward by suppressing the downward and backward movement and downward turning of the inertial body.

The calculation means is divided into a target torque, a drive torque for driving the inertia body by the motor, and a driven torque for driving the motor by the inertia body, using a calculation algorithm stored in advance. In this arithmetic algorithm, the absolute value of the drive torque increases as the absolute value of the operation amount at the operating end increases, and the operation amount at the operation end is constant. Even if the absolute value of the rotational speed of the motor increases, the drive torque calculation algorithm decreases, and the absolute value of the driven torque increases as the absolute value of the operation amount of the operation end decreases, and the operation amount of the operation end becomes constant. Even if the absolute value of the rotational speed of the motor decreases, at least the drive torque calculation algorithm among the driven torque calculation algorithms becomes smaller. By incorporating it, the control design of the output torque of the motor can be performed in the same manner as in the case of the control of the hydraulic motor torque by the control throttle of the control valve. As well as being able to operate the inertial body by holding it, as with the hydraulic drive system, it is possible to change the acceleration force of the motor to deceleration and change from deceleration to acceleration continuously and smoothly.

[0035] The above calculation algorithm is added with the calculation of the resistance torque to reduce the target torque, The absolute value of torque increases as the absolute value of the rotational speed of the motor increases, and by incorporating one or both of an algorithm for reducing the absolute value of the drive torque and an algorithm for increasing the absolute value of the driven torque. By adding to the control system a resistance torque element equivalent to the pressure loss in the hydraulic drive system in addition to the resistance of the common drive system, the balance between the actual output torque of the motor and the load torque is further stabilized. Can be stably controlled to achieve the intended target speed.

Brief description of the drawings

FIG. 1 is a side view showing a hydraulic shovel incorporating a control device for an electric motor according to the present invention.

[FIG. 2] A block diagram showing a configuration of a control device of a motor incorporated in the hydraulic shovel of FIG. 1. [FIG. 3] A graph showing a basic map of the calculation algorithm of FIG.

[FIG. 4] A graph showing the target torque in the first quadrant and the fourth quadrant of the graph of FIG. 3 disassembled into a driving torque and a driven torque.

[Figure 5] A graph showing the resistance torque computed by the computation algorithm of Figure 2

[Fig. 6] A graph showing the driven torque calculated in the range where the absolute value of the rotational speed is near zero with the operation algorithm of Fig. 2

[Figure 7] Piping system diagram of conventional hydraulic drive

[FIG. 8] A graph showing control characteristics of bleed off pressure in the hydraulic drive system of FIG.

[FIG. 9] A graph showing control characteristics of meter-out pressure in the hydraulic drive system of FIG.

[Figure 10] Graph showing the control characteristics in which the absolute value of the rotational speed is near zero in the conventional electric drive system

Explanation of sign

[0037] 1 Motor

la rotation detection means

2 Control lever

2a Operation detection means

3 controller

3a memory

3b arithmetic algorithm 4 inverter

4a Signal conversion circuit

4b current control circuit

20 running body

21 Traveling hydraulic motor

22 Speed reducer

30 swiveling body

31 engine

32 hydraulic pumps

33 Generator

34 Power storage device

35 reducer

36 converter

40 Drilling attachment

41 boom

41a Boom cylinder

42 arm

42a arm cylinder

43 Nocket

43a bucket cylinder

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 shows a hydraulic shovel incorporating the motor control device according to the present invention. This hydraulic shovel includes a crawler type lower traveling body 20, an upper rotating body 30 as an inertial body which pivots left and right on the lower traveling body 20, and an excavating attachment attached to a front portion of the rotating body 30. And 40. The lower traveling body 20 travels by driving the left and right crawlers 23 separately by the traveling hydraulic motor 21 and the reduction gear 22. The drilling attachment 40 includes a boom 41, an arm 42 and a packet 43, a boom cylinder 41a for operating them, an arm cylinder 42a and a bucket cylinder. Da 43a is equipped.

The revolving unit 30 includes an engine 31, a hydraulic pump 32 and a generator 33 driven by the engine 31, a power storage device 34 such as a notch or a capacitor, and a motor 1 for causing the revolving unit 30 to swing. A reduction gear 35 is mounted. The discharge oil of the hydraulic pump 32 is supplied to the traveling hydraulic motor 21 and the boom 41, the arm 42, and the cylinders 41a of the notch 43 via control valves. The power of the generator 33 is controlled by the converter 36 so that the voltage and current are controlled and stored in the storage device 34, and is also supplied to the motor 1 through the inverter 4 described later. The electric motor 1 is a permanent magnet type motor having a permanent magnet as a rotor, and the control device of the electric motor according to the present invention controls the electric motor 1 to cause the turning body 30 to perform a turning operation.

FIG. 2 is a block diagram showing a configuration of a control device of the motor 1. This control device comprises an operation detection means 2a for detecting the operation amount X of the operation lever 2 as plus and minus in both directions as an operation end, and a rotation detection means la for detecting the plus and minus rotational speed N of the motor 1 rotating in both directions. The controller 3 as a computing means for computing the direction and magnitude of the target torque To to be borne by the motor 1 from the detected operation amount X of the control lever 2 and the rotational speed N of the motor 1 And the inverter 4 as motor control means for controlling the output torque T of the motor 1 to the direction and magnitude of the target torque To calculated by the controller 3 with respect to the power supplied from the motor 33 or the storage device 34 ing.

The controller 3 is provided with a memory 3a, and an arithmetic algorithm 3b for dividing the target torque To into a driving torque Ta and a driven torque Tb so as to express the control characteristic of the hydraulic driving system, It is stored in advance in the memory 3a. The target torque To is calculated as the sum of the driving torque Ta and the driven torque Tb, and the calculated target torque To is a torque in the case where it is output in the same direction as the operation direction of the control lever 2. If it is output in the direction opposite to the operation direction, it is the regenerative torque. In addition, the inverter 4 includes a signal conversion circuit 4a and a current control circuit 4b. The signal conversion circuit 4a converts the target torque To input from the controller 3 into a target current Io, and the current control circuit 4b outputs an output to the motor 1 Feedback control is performed to set the current I to the target current Io.

FIG. 3 shows a basic map for calculating the target torque To by the calculation algorithm 3b. This In the basic map, the horizontal axis is the plus / minus manipulated variable X of the control lever 2 and the vertical axis is the target torque To, and the relationship between them is a characteristic curve with the plus or minus rotational speed N of the motor 1 as a parameter. In the first and third quadrants in which the manipulated variable X and the target torque To have the same sign, the target torque To is a positive torque, and the manipulated variable X and the target torque To have a different sign in the second quadrant In the fourth quadrant, the target torque To is the regenerative torque. That is, in the first quadrant, it is right turn regeneration, in the second quadrant it is left turn regeneration, in the third quadrant it is left turn clearance, and in the fourth quadrant it is right turn regeneration. In the graph of FIG. 3, in order to make the map easy to see, the characteristic curves are shown only in the case of the parameter rotation speed N = 0, 1/2, 1 (maximum speed).

In the first quadrant and the third quadrant of the basic map, the absolute value of the target torque To, which is the torque to be applied, increases as the absolute value of the operation amount X of the operation lever 2 increases, and the operation amount X becomes constant. Even in this case, the absolute value of the rotational speed N of the motor 1 is calculated so as to decrease as the absolute value of the rotational speed N increases, and the same control characteristic as the control of the bleed-off pressure of the hydraulic drive system can be obtained. Also, in the second and fourth quadrants of the basic map, the absolute value of the target torque To, which is the regenerative torque, increases as the absolute value of the manipulated variable X decreases, and even if the manipulated variable X is constant, the rotational speed It is calculated so as to become smaller as the absolute value force S of N becomes smaller, and a control characteristic similar to that of the meter-out pressure control in the hydraulic drive system can be obtained.

Further, in the basic map shown in FIG. 3, when the operation amount X is in the neutral range including zero and when the operation direction of the operation lever 2 and the rotation direction of the motor 1 are in the opposite direction, The torque is zero, and the absolute value of the regenerative torque is set to the maximum value Tmax. Therefore, for example, when the rotational speed N = 1Z2 (point Q) in the fourth quadrant, as indicated by the arrow in the figure, the operation amount X of the control lever 2 from X to X the direction of rotation of the motor 1 When operating in the opposite direction, the rotational speed N is

1 2

Until it reaches zero, the regenerative torque is output at Tmax and the right turn is decelerated, and the rotational speed N becomes zero, the rotational speed when the manipulated variable X is −X in the third quadrant N = 0 ( Equivalent to point Q)

The torque to move 2 2 is output, and acceleration is started to turn the swing body 30 to the left. Note that, in this embodiment, the absolute value of the steering torque is also set to the same maximum value Tmax as the regenerative torque.

[0045] FIG. 4 shows the target torque To as a solid line for the first quadrant and the fourth quadrant that turn to the right in FIG. The driving torque Ta and the driven torque Tb indicated by a dotted line are shown in the form of a disassembly. The driving torque Ta corresponds to the torque due to the meter-in pressure of the hydraulic motor, and the driven torque Tb corresponds to the torque due to the meter-out pressure of the hydraulic motor. The absolute value of the driving torque Ta in the first quadrant increases as the absolute value of the manipulated variable X increases, and is calculated so as to decrease as the absolute value of the rotational speed N increases, even if the manipulated variable X is constant. Maximum value Tamax is set. Also, the absolute value of the driven torque Tb in the fourth quadrant increases as the absolute value of the manipulated variable X decreases, and decreases as the absolute value of the rotational speed N decreases, even if the manipulated variable X is constant. In the third quadrant where the operation amount X is zero and the operating direction of the control lever 2 and the rotation direction of the motor 1 are opposite, the maximum value Tbmax is set. . The target torque To shown in the first quadrant and the fourth quadrant of FIG. 3 is obtained as the sum of the driving torque Ta and the driven torque Tb thus calculated. Although illustration is omitted, the target torque To in the second and third quadrants of FIG. 3 which turns left is also obtained as the sum of the drive torque Ta and the driven torque Tb which are similarly calculated.

The graph of FIG. 5 shows a resistance torque ΔΤ that reduces the target torque To calculated by the calculation algorithm 3b. The resistance torque ΔΤ increases as the absolute value of the rotational speed N of the motor 1 increases, and decreases the absolute value of the drive torque Ta calculated in the first and third quadrants. The second and fourth quadrants are added so as to increase the absolute value of the calculated driven torque Tb, and a point at which the actual output torque and load torque are balanced, as in the pressure loss in the hydraulic drive system. Stabilize and allow stable control to achieve the operator's intended target speed. The absolute value of the resistance torque ΔΤ increases in proportion to the first to second orders relative to the absolute value of the rotational speed N of the motor 1.

In the graph of FIG. 6, when the operation amount X of the operation lever 2 is in the neutral range, or when the operation direction of the operation lever 2 and the rotation direction of the motor 1 are in the opposite direction, the arithmetic algorithm 3b is used. The calculated driven torque Tb in the small range near zero of the absolute value of the rotational speed N of the motor 1 is shown. The driven torque Tb is calculated so as to increase in accordance with the magnitude of the absolute value of the rotational speed N in a range where the absolute value of the rotational speed N is small near zero, and turns the revolving unit 30 upward on a slope. When the driving torque Ta is smaller than the load torque due to the inclination, reverse rotation of the motor 1 in the downward direction is suppressed. Drive torque Ta is larger than load torque Then, the rotating body 30 smoothly starts turning upward by the driving torque Ta. In this case, turn right upward.

In the embodiment described above, the generator and the storage device are used as an electric power source to control the electric motor that turns the upper turning body of the hydraulic shovel left and right, but the control device of the electric motor according to the present invention For example, the present invention can be applied to one that controls a motor that operates an inertial body in only one direction, such as one that drives a wheel loader. Also, the power source of the motor is not limited to the generator or the storage device. For example, in the case of controlling the motor that operates the inertia body of the device fixed in a factory, the power supplied from the power company or the like It can be a power source.

Furthermore, in the above-described embodiment, the calculation algorithm of the drive torque and the drive torque is stored in the controller as the characteristic curve represented by the map, but the calculation algorithm of the drive torque and the drive torque is Let's store it as a mathematical expression with the operation amount of the operation end and the rotational speed of the motor as parameters.

Claims

The scope of the claims

[1] Operation detection means for controlling the rotational drive of the motor for operating the inertial body by the operation of the operating end at least making the operating amount variable, and detecting the operating amount of the operating end, the rotational direction and rotational speed of the motor And calculating means for calculating a target torque to be borne by the motor based on the detection values of the operation detecting means and the rotation detecting means, and the output torque of the motor as the target torque. A control device for a motor comprising: motor control means for controlling in a direction and a magnitude of torque, wherein the output torque is composed of a momentary torque as a motor function of the motor and a regenerative torque as a generator function. When the absolute value of the amount of operation of the operating end increases, the torque of the motor increases, and even if the amount of operation of the operating end is constant, the absolute value of the rotational speed of the motor is large That the control unit for an electric motor, characterized in that incorporates a small and that algorithm.

[2] In the calculation means, the regenerative torque increases as the absolute value of the operating amount at the operating end decreases, and the absolute value of the rotational speed of the motor decreases even if the operating amount at the operating end is constant. The control device for a motor according to claim 1, which incorporates an algorithm that becomes smaller.

[3] The operation end is capable of rotating the electric motor in both plus and minus directions by setting the operation direction variable in plus and minus directions in addition to the operation amount, and the operation detection means comprises the operation amount and plus of the operation end. A negative operating direction is to be detected, and when the operating amount of the operating end is in the neutral range including zero, or when the operating direction of the operating end and the rotational direction of the electric motor are in the opposite direction. 3. The control device of the motor according to claim 1, further comprising an algorithm for setting the feed torque to zero and the regenerative torque to a maximum value.

[4] The operation end is capable of rotating the electric motor in both plus and minus directions by setting the operation direction variable in plus and minus directions in addition to the operation amount, and the operation detection means comprises the operation amount and plus of the operation end. A negative operating direction is to be detected, and when the operating amount of the operating end is in the neutral range including zero, or when the operating direction of the operating end and the rotational direction of the electric motor are in the opposite direction. The absolute value of the regenerative torque is set to a value within the range where the absolute value of the rotational speed of the motor is close to zero. 4. A control device of a motor according to any one of claims 1 to 3, wherein an algorithm for increasing the magnitude according to the magnitude of the absolute value is incorporated.

[5] The computing means divides the target torque into a driving torque for driving the inertial body by the motor and a driven torque for driving the motor by the inertial body according to an arithmetic algorithm stored in advance. In the calculation algorithm, the absolute value of the drive torque increases as the absolute value of the operation amount of the operation end increases, and the operation amount of the operation end increases. Even if it is constant, the drive torque calculation algorithm decreases as the absolute value of the rotation speed of the motor increases, and the absolute value of the drive torque increases as the absolute value of the operation amount of the operating terminal decreases. Even if the operation amount of the cutting edge is constant, a smaller one of the driven torque calculation algorithm becomes smaller as the absolute value of the rotational speed of the motor becomes smaller. The motor controller according to any one of Kutomo claims 1 to 4 incorporating the driving torque calculation algorithm.

[6] The calculation of the resistance torque for reducing the target torque is added to the calculation algorithm, and the absolute value of the resistance torque becomes larger as the absolute value of the rotation speed of the motor increases. The control device for a motor according to claim 5, wherein one or both of an algorithm to reduce and an algorithm to increase the absolute value of the driven torque are incorporated.

[7] The control device for a motor according to any one of claims 1 to 6, wherein the inertia body operated by the electric motor is an inertia body operated by a turning operation or a traveling operation of a construction machine.