JP2010193541A - Device for controlling electric motor for use in driving construction machine arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance safety and workability with respect to a speed command by which the swiveling direction of an arm is abruptly changed in a method for driving and controlling the movement of the arm with an arm driving motor and an inverter. <P>SOLUTION: In a construction machine having an arm, the arm driving motor 6 as power for moving the arm is controlled with the inverter 7. When a control signal for operating the arm is input to the inverter 7, an acceleration and deceleration decision unit 2 determines whether the control signal is a command to accelerate the arm driving motor 6 or a deceleration command. According to the decision by the acceleration and deceleration decision unit 2, a filter constant for a filter unit 4 is set and the arm driving motor 6 is controlled based on the set filter constant. When a speed command value different in swiveling direction is input to the inverter 7, the acceleration and deceleration decision unit 2 decelerates the arm driving motor 6 and determines that the command is for acceleration after the speed of the arm driving motor 6 is zeroed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a speed control device that moves an arm in a system that uses an electric motor as a power for moving the arm and uses an inverter to drive the electric motor.

  Currently, the power for moving the arm of a construction machine having an arm, such as a shovel car, in the left-right direction is a hydraulic motor, and this motor is driven by a high pressure and a large amount of oil generated by a diesel engine and a hydraulic pump. The turning direction and speed are controlled by adjusting the direction and flow rate with a control valve provided between the hydraulic pump and the hydraulic motor. Disadvantages are inefficiency, high pressure, and the use of a large amount of oil, which necessitates maintenance in consideration of environmental and safety such as oil leakage and fire.

  In order to solve these matters, in recent years, the emergence of small, highly efficient and powerful motors and the small and high performance inverters that drive these motors, the power to move the arm in the turning direction, Combinations of electric motors and inverters have begun to be used.

  As shown in FIG. 12, the operating method of the arm driven by this electric motor is as follows. The operation lever 1 is set to 0 when the lever is in the center. A signal is output. In this way, the turning direction and speed are adjusted by tilting the operating lever 1, but play is provided as a dead zone area near the center, and the turning direction is commanded in the direction in which the operating lever 1 is tilted left and right. The degree of turning speed is adjusted by the tilt of the lever.

  FIG. 13 shows a configuration diagram of the arm control inverter. The operation is performed so that the movement intended by the operator can be realized by the operation lever 1, and a command signal from the operation lever 1 is output to the filter unit 4. The filter unit 4 is provided for removing noise due to mechanical vibration generated by the vibration of the construction machine itself and shaking the operation lever 1 and adjusting the response speed. The filter unit 4 outputs a turn direction and speed command signal to be realized by the inverter 7 to the control unit 5, and the control unit 5 drives the arm driving motor 6 and moves the arm in accordance with the output. Since the filter unit 4 is used for both acceleration and deceleration, the response speed is the same during acceleration and deceleration.

  Patent Documents 1 and 2 are publicly known as arm control for construction machines. Patent Document 1 describes that an inverter is used to control an electric motor, and a control signal from a lever is input to a controller of the inverter to control the electric motor. Further, Patent Document 2 describes that the electric motor is controlled so that the response speed varies depending on the rise and fall of the lever signal.

JP 2001-226077 A International Publication No. 2006/054541 Pamphlet

Arm turning speed, which is considered good for safety, workability and environmental friendliness and ergonomics, is a slow response when accelerating, a fast response when decelerating, and no rapid acceleration / deceleration. That is. At present, the response speed is the same for both acceleration and deceleration, and the response speed is often set faster in response to the deceleration. There is a problem of lowering and poor workability. In addition, when the vehicle is suddenly decelerated from sudden acceleration, there is a problem that an excessive force due to time differentiation of the speed is applied to the arm, and vibration and noise are generated to deteriorate environmental conditions.

  An object of the present invention is to improve workability, safety, and environmental performance in a construction machine having an arm that uses an electric motor as power for moving the arm and uses an inverter to drive the electric motor. Therefore, the response speed at the time of acceleration and deceleration of the arm operation can be adjusted separately at each time. In particular, in the system described above, the response speed at the time of acceleration and deceleration of the arm driving motor can be adjusted separately for each command in response to a command to change the turning direction of the arm abruptly.

  A control device for an arm drive motor of a construction machine according to the present invention that achieves the above object is an inverter that controls an electric motor that moves the arm in a construction machine having an arm, and commands the turning direction and speed of the arm. When a speed command value, which is an output signal of the operation lever, is detected at a predetermined fixed interval and a change amount of the speed command value is larger than a predetermined determination value, An acceleration / deceleration determination processing unit that determines whether the input signal is a command value for accelerating or decelerating the arm, a time constant for acceleration state, and a time constant for deceleration state are set separately, and the acceleration / deceleration Based on the time constant for acceleration state time constant and the time constant for deceleration state that select any one of the time constants according to the determination processing signal of the determination processing unit, and the time constant signal selected based on the selected time constant signal. The acceleration / deceleration determination processing unit has a change amount smaller than the determination value and a sign of the filter output value has changed. In this case, it is determined that the arm is accelerated, and it is determined that the arm is decelerated when a speed command value having a different turning direction of the arm is input at the predetermined fixed interval.

  Also, the control device for the arm drive motor of the construction equipment according to the present invention that achieves the above object is an inverter that controls the motor that moves the arm in the construction machine having the arm, and the turning direction and speed of the arm A command input device for commanding a pulse signal and a speed command value that is an output signal of the command input device are detected, and it is determined whether the input signal of the command input device is a command value for accelerating or decelerating the arm. Acceleration / deceleration determination processing unit, acceleration state time constant and deceleration state time constant are set separately, and one of the time constants is selected according to the determination processing signal of the acceleration / deceleration determination processing unit Based on the time constant for acceleration state time constant and the time constant for deceleration state to be selected and the selected time constant signal, a filter that outputs a command value for the turning direction and speed of the motor as a filter output value. The acceleration / deceleration determination processing unit determines that the arm is accelerated when the command from the command input device does not change and the sign of the filter output value changes, from the command input device, When a speed command value having a different turning direction of the arm is input, it may be determined that the arm is decelerated.

  The time constant may be set so that the response speed during acceleration is slower than the response speed during deceleration.

  Therefore, according to the above invention, safety and workability are improved in the system in which the operation of the arm is driven and controlled by the electric motor and the inverter.

The block diagram which shows 1st Embodiment of this invention. FIG. 3 is a determination flowchart of the first embodiment. The block diagram which shows the example of control of the electric motor for arm drive. FIG. 4 is a determination flow diagram of an example of control of an arm driving motor. The block diagram which shows 2nd Embodiment of this invention. FIG. 10 is a determination flowchart of the second embodiment. Filter input / output waveform diagram. Filter output waveform diagram when the time constant for acceleration state is selected during deceleration. The filter output waveform figure at the time of selecting the time constant for the deceleration state at the time of acceleration. The relationship diagram of the speed command value and control cycle which are input. The required filter output waveform diagram. Operation lever actual state diagram and input / output relationship diagram. FIG.

  In the present invention, the arm operation is driven and controlled by an arm drive motor and an inverter. In order to improve safety and workability, each filter is used for arm drive by using a dedicated filter constant during acceleration and deceleration. It adjusts the responsiveness of the motor separately. In particular, when a command to change the turning direction of the arm suddenly is input, when the arm drive motor decelerates, the filter constant for deceleration (time constant for deceleration state) is selected, and the rotation speed of the arm drive motor After the value becomes zero, the arm driving motor is controlled so as to switch to the filter constant during acceleration (time constant for acceleration state).

  Prior to the present invention, the inventors have invented an arm drive motor control device. The configuration is shown in FIG.

  As shown in FIG. 3, the arm (not shown) is driven and controlled by the inverter 7 driving and controlling the arm driving motor 6 based on the input of the operation lever 1.

  The arm control lever 1 sets two conditions of the arm turning direction and speed. In other words, the turning direction is instructed in the direction in which the operation lever 1 is tilted left and right, and the degree of turning speed is adjusted by the inclination of the lever. For example, the turning speed signal is output with a positive signal when tilted to the right and a negative signal when tilted to the left. In this way, the turning direction and speed are adjusted by tilting the operation lever 1. In the vicinity of the center, play is provided as a dead zone region.

  The inverter 7 includes an acceleration / deceleration determination processing unit 2, an acceleration state time constant, a deceleration state time constant selection unit 3 (hereinafter referred to as a time constant selection unit 3), a filter unit 4, a control unit 5, and a filter difference. It is comprised from the calculating part 9 (henceforth the calculating part 9).

  As shown in FIG. 7, the arithmetic unit 9 suppresses the rapid acceleration change of the arm driving motor 6 when the rapid command is issued from the sudden acceleration as the speed command in the transition from the acceleration state to the deceleration state. Provided to improve safety.

  In FIG. 7, the solid line indicates the speed command value when sudden acceleration is issued from sudden acceleration as the speed command. On the other hand, the dotted line indicates the filter output value (dotted line) when the speed command value indicated by the solid line is input.

  The calculation unit 9 obtains a difference (filter difference) between the speed command value from the operation lever 1 and the filter output value from the filter unit 4. This calculation result is used for time constant setting of the time constant setting unit 8.

  The time constant setting unit 8 includes an acceleration / deceleration determination processing unit 2 and a time constant selection unit 3, and sets a filter constant for the filter unit 4.

  The acceleration / deceleration determination processing unit 2 receives signals from the calculation unit 9 and the operation lever 1 and determines whether the command is an acceleration state command or a deceleration state command.

  That is, based on the sign of the speed command value and the sign of the filter difference, the acceleration / deceleration determination processing unit 2 switches from the acceleration state to the deceleration state.

  The time constant selection unit 3 stores a time constant for acceleration and a time constant for deceleration. Then, the acceleration / deceleration determination processing unit 2 outputs an acceleration / deceleration determination to the time constant selection unit 3, and the time constant selection unit 3 selects either the acceleration or deceleration time constant to select the filter constant of the filter unit 4. Set up.

  Therefore, the arm driving electric motor 6 can be switched from smooth acceleration to deceleration, and an excessive force is prevented from being applied to the arm.

  The control unit 5 outputs a control signal to the arm driving motor 6 when a filter output value that is a turning direction and a speed instruction is input from the filter unit 4.

  Thus, the arm driving motor 6 is driven and controlled by the inverter 7. The arm is driven and controlled by driving and controlling the arm driving motor 6. With the configuration as described above, the operation will be described with reference to the flowchart of FIG.

  In step S1, it is determined whether the arm speed command is an acceleration state or a deceleration state. This determination is made from the amount of change in the speed command value from the operation lever 1. That is, a signal including two conditions of a turning direction and a speed command value is periodically transmitted from the operation lever 1 to the acceleration / deceleration determination processing unit 2.

  Since the acceleration / deceleration determination processing unit 2 extracts only information related to the speed from the speed command value, the positive / negative polarity instructing the turning direction is removed by the absolute value calculation, and then the amount of change in the speed command value is calculated by Expression (1) .

Amount of change = | current speed command value |-| previous speed command value | (1)
Further, the speed command value generated by the operation lever 1 includes, as an error, a vibration width caused by mechanical vibration that the operation lever 1 itself receives. Therefore, about 1.5 to 2 times the amplitude is appropriately set as the determination value. If the change amount of the speed command value calculated from the equation (1) is larger than the set value, it can be determined that the acceleration or deceleration speed command has been made. Become more certain. The determination value is calculated by equation (2).

Judgment value = (noise due to mechanical vibration of the lever) × about 1.5 to 2 (2)
In step S2, the current speed command value is held. The speed command value held in step S2 is input as the previous speed command value at the time of calculating the next change amount (formula (1)).

  In step S <b> 3, a difference between the speed command value from the operation lever 1 and the filter output value from the filter unit 4 (hereinafter, referred to as a filter difference) is calculated by the calculation unit 9 using Equation (3).

Filter difference = | Speed command value |-| Filter output value | (3)
The calculated filter difference is output to the acceleration / deceleration determination processing unit 2. As shown in FIG. 7, when the filter difference changes from positive to negative (point P), it is possible to realize smooth switching between acceleration and deceleration of the arm driving motor 6 by determining the acceleration state to the deceleration state.

  In step S4, the acceleration / deceleration determination processing unit 2 compares the absolute value of the speed command value change amount (calculated from equation (1)) and the determination value (calculated from equation (2)) calculated in step S1. Do. When the absolute value is larger than the determination value (in the case of Y), the process proceeds to step S5 to determine whether the speed command value is a command for accelerating or decelerating the arm driving motor 6. On the other hand, if the absolute value is smaller than the determination value (N), the current time constant is set in step S10.

  In step S5, the acceleration / deceleration determination processing unit 2 adds the filter difference condition calculated in step S3 to the change amount sign condition calculated in step S1, and determines the acceleration state in equation (4). Based on.

Change amount> 0 and filter difference> 0 (4)
When Expression (4) is satisfied (in the case of Y), in step S6, the time constant selection unit 3 selects a time constant for acceleration state. On the other hand, when Expression (4) is not satisfied (in the case of N), the process proceeds to step S7.

  In step S7, the acceleration / deceleration determination processing unit 2 determines the deceleration state based on the equation (5).

Change amount <0 and filter difference <0 (5)
When the expression (5) is satisfied (in the case of Y), in step S8, the time constant selection unit 3 selects the time constant for the deceleration state. On the other hand, when Expression (5) is not satisfied (in the case of N), the process proceeds to step S9, and the time constant currently set by the time constant selection unit 3 is selected.

  In step S11, the time constant selected in any one of steps S6, S8, S9, and S10 is set as the filter constant of the filter unit 4.

  Based on the set filter constant, the turning direction and the speed signal are input from the filter unit 4 to the control unit 5, and the response speeds in the acceleration state and the deceleration state of the arm driving motor 6 are controlled separately.

  The series of operations (S1 to S11) is set as a control cycle, and the control of the arm driving motor 6 is performed by repeating this control cycle. Therefore, workability and safety of the arm are improved.

  A specific example of the control method of the arm driving electric motor having the above-described configuration is shown below. In the specific example, the right turn direction is positive.

For example, when the current speed command value is 3000 rpm and the previous speed command value is 2000 rpm, it is required to accelerate the arm drive motor 6 so that the right rotational speed is increased by 1000 rpm. When this is controlled by the inverter 7, each value is substituted into the equation (1),
Change amount = | 3000 | − | 2000 | = 1000
Thus, since the amount of change is> 0, it is determined that acceleration.

Similarly, when the current speed command value is −3000 rpm and the previous speed command value is −2000 rpm, it is required to accelerate the arm drive motor 6 so that the left rotation speed is increased by 1000 rpm. When this is controlled by the inverter 7, the respective values are substituted into the equation (1),
Change amount = | −3000 | − | −2000 | = 1000
Thus, since the amount of change is> 0, it is determined that acceleration.

  As described above, the inverter 7 can appropriately control the arm driving motor 6 with respect to a command in which the turning direction does not change between the previous command and the current command.

  However, in the control method of the arm driving electric motor 6 having the above-described configuration, there is a possibility that the acceleration and deceleration are erroneously determined in response to a command in which the turning direction changes rapidly.

For example, when the current speed command value is 3000 rpm (right turn is positive) and the previous speed command value is −2000 rpm, the arm drive motor 6 decelerates the right turn direction and the arm drive motor 6 After the rotation speed becomes zero, acceleration in the left turn direction is required. When this is controlled by the inverter 7, the respective values are substituted into the equation (1),
Change amount = | 3000 | − | −2000 | = 1000
Thus, since the amount of change is> 0, it is determined that acceleration. Therefore, as shown in FIG. 8, the inverter 7 is uniformly determined to accelerate.

Similarly, when the current speed command value is 2000 rpm (right turn is positive) and the previous speed command value is −3000 rpm, the required movement of the arm driving motor 6 is reduced in the right turn direction. Then, after the rotational speed of the arm drive motor 6 becomes zero, it is accelerated in the left turning direction. When this is controlled by the inverter 7, the respective values are substituted into the equation (1),
Change amount = | 2000 | − | −3000 | = −1000
Since the change amount is less than 0, it is determined that the vehicle is decelerating. Therefore, as shown in FIG. 9, the inverter 7 is uniformly determined to decelerate.

  That is, since a uniform time constant is selected based on the difference between the absolute value of the current speed command value and the previous speed command value, the time constant is switched after the rotational speed of the arm driving motor 6 becomes zero. I can't.

  Such a problem is not so serious in the case of input by lever operation. This is because, as shown in FIG. 10, the operation of the lever is much slower than the control cycle sampled by the inverter 7, and therefore, as shown by the arrow B in FIG. This is because there is little to be done.

  However, even in a system that uses lever operation, the speed control cycle becomes slow for the convenience of the system, and the above-mentioned problem occurs when a command for suddenly changing the turning direction within the control cycle is input. In addition, in a device (command input device) in which the left and right turn command button signals (such as hoist operation buttons) have only strong and weak commands (for example, high-speed commands or low-speed commands), they are pulse-like. Since a signal is input, the above-described problem is likely to occur.

  In consideration of the above problems, the present invention uses the time constant for deceleration state when the rotational speed of the arm driving motor 6 approaches 0 as shown in FIG. When the speed increases, the arm driving motor 6 is controlled to use the time constant for the acceleration state. Hereinafter, specific embodiments will be described in detail.

(Embodiment 1)
FIG. 1 shows a block diagram for realizing the arm driving motor control method according to the first embodiment of the present invention. The arm (not shown) is driven and controlled when the inverter 7 drives and controls the arm driving motor 6 based on the input of the operation lever 1. The same components as those for realizing the control method of the arm driving motor 6 in FIG. 3 are denoted by the same reference numerals and detailed description thereof is omitted.

  The present invention has a function of detecting that an instruction having a different turning direction is input within the control cycle in the configuration for realizing the control of the arm driving motor 6 shown in FIG. It is characterized by that. Hereinafter, the function of the acceleration / deceleration determination processing unit 2 will be described in detail.

  The acceleration / deceleration determination processing unit 2 calculates the product (sign determination value) of the current speed command value and the previous speed command value, and determines whether the calculated value is positive or negative. That is, the acceleration / deceleration determination processing unit 2 detects that a speed command value having a different turning direction is input from the operation lever 1 between the previous speed command value and the current speed command value.

  For example, if the sign of the right turn speed command value is positive, the sign of the left turn speed command value is negative. Therefore, when a speed command value having a different turning direction is input between the previous speed command value and the current speed command value, the sign of the sign determination value is always negative. Therefore, by detecting the sign of the sign determination value, it is possible to detect that a speed command value having a different turning direction is input between the previous speed command value and the current speed command value.

  The acceleration / deceleration determination processing unit 2 always determines “deceleration” when the sign determination value (product of the current speed command value and the previous speed command value) is negative. Thereafter, the sign of the filter output value is detected, and “acceleration” is determined when the sign of the filter output value changes (when the turning direction changes). Based on the determination of the acceleration / deceleration determination processing unit 2, the time constant selection unit 3 selects a time constant.

  A method for controlling the arm driving motor 6 having the above-described configuration will be described in detail with reference to the flowchart shown in FIG. The same steps as those in the flow shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In step S <b> 1, a signal including two conditions of the turning direction and speed from the operation lever 1 is periodically transmitted to the acceleration / deceleration determination processing unit 2. The acceleration / deceleration determination processing unit 2 calculates the change amount of the speed command value based on the equation (1).

  In step S2, the current speed command value is saved.

  In step S <b> 3, the calculation unit 9 calculates the filter difference based on the equation (3), and the calculated filter difference is output to the acceleration / deceleration determination processing unit 2.

  In step S4, the acceleration / deceleration determination processing unit 2 compares the absolute value of the speed command value change amount (calculated from equation (1)) and the determination value (calculated from equation (2)) calculated in step S1. Do.

  When the absolute value is larger than the determination value (in the case of Y), the process proceeds to step S12, and it is determined whether or not a command for suddenly turning the arm is input to the acceleration / deceleration determination processing unit 2. On the other hand, when the absolute value is smaller than the determination value (in the case of N), the process proceeds to step S14, and a sign change of the filter output value is detected.

  In step S12, the acceleration / deceleration determination processing unit 2 calculates a sign determination value using Equation (6).

Sign judgment value = (previous speed command value) × (current speed command value) (6)
In step S13, the sign determination value calculated in step S12 is detected. Here, “left turn speed command value (negative) × right turn speed command value (positive) = sign judgment value (negative)”, “right turn speed command value (positive) × left turn speed command” Since “value (negative) = sign determination value (negative)”, if the sign of the sign determination value is negative, it can be determined that the turning direction command is different between the previous speed command value and the current speed command value.

  If it is detected in step S13 that the sign determination value is negative (in the case of N), it is determined that the previous speed command value and the current speed command value are different in the turning direction command. In this case, since the rotational speed of the arm driving motor 6 is always “decelerated”, the time constant selecting unit 3 selects the time constant for the deceleration state through steps S7 and S8.

  On the other hand, if the sign of the sign determination value is positive (Y) in step S13, the process proceeds to step S5 in the same manner as the invention prior to the present invention shown in the flow of FIG. However, since it is determined whether the speed command from the operation lever 1 is a command for accelerating the arm driving motor 6 or a command for decelerating, the description is omitted here.

  In step S4, if the absolute value is smaller than the determination value (N), the sign of the filter output value is determined in step S14. If there is a change in the sign of the filter output value (in the case of N), the process proceeds to step S6 and the acceleration time constant is selected. On the other hand, when there is no sign change in the filter output value (in the case of Y), the time constant selection unit 3 selects the current time constant in step S10.

  In step S11, the time constant selected in any of steps S6, S8, S9, and S10 is set as the filter constant of the filter unit 4.

  The series of operations (S1 to S14) is set as a control cycle, and the control of the arm driving motor 6 is performed by repeating this control cycle.

  As described above, when a command with a different turning direction is input, the rotational speed of the arm drive motor 6 is set to “decelerate”, and after the rotational speed of the arm drive motor 6 becomes 0 in step S14, the arm drive is performed. The rotation speed of the motor 6 can be switched to “acceleration”.

(Embodiment 2)
The configuration of the second embodiment of the present invention is shown in FIG. As shown in FIG. 5, in the second embodiment of the present invention, the configuration of the inverter 7 is simplified in the configuration for realizing the control method of the arm driving motor 6 shown in FIG. 1. Therefore, even if a command for suddenly changing the turning direction is input, the acceleration time constant can be selected during acceleration and the deceleration time constant can be selected during deceleration to control the arm driving motor 6. .

  The arm (not shown) is driven and controlled by driving and controlling the arm driving motor 6 by the inverter 7 based on the input of the operation lever 1. The same components as those for realizing the control method of the arm driving motor 6 in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The inverter 7 includes an acceleration / deceleration determination processing unit 2, a time constant selection unit 3, a filter unit 4, and a control unit 5.

  In the control method according to the second embodiment, when the speed command value of the operation lever 1 is input, the acceleration / deceleration determination processing unit 2 outputs the input signal based on the sign change of the change amount of the speed command value. 6 is judged whether it is a signal for accelerating or decelerating. That is, it is determined that the acceleration state is satisfied when the expression (7) is satisfied, and the deceleration state is satisfied when the expression (8) is satisfied.

Change amount> 0 (7)
Amount of change <0 (8)
A control method of the arm driving motor 6 having the above-described configuration will be described in detail with reference to the flowchart shown in FIG. The same steps as those in the flow shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In step S <b> 1, a signal including two conditions of the turning direction and speed from the operation lever 1 is periodically transmitted to the acceleration / deceleration determination processing unit 2. The acceleration / deceleration determination processing unit 2 calculates the change amount of the speed command value based on the equation (1).

  Next, the current speed command value is saved in step S2.

  In step S4, the acceleration / deceleration determination processing unit 2 compares the absolute value of the speed command value change amount (calculated from equation (1)) and the determination value (calculated from equation (2)) calculated in step S1. Do. When the absolute value is larger than the determination value (in the case of Y), the process proceeds to step S12, and it is determined whether or not a command having a different turning direction between the previous speed command value and the current speed command value is input. On the other hand, when the absolute value is smaller than the determination value (in the case of N), the process proceeds to step S14, and a sign change of the filter output value is detected.

  In step S12, the acceleration / deceleration determination processing unit 2 calculates a sign determination value using Equation (6).

  In step S13, the sign judgment value calculated in step 12 is detected. When it is detected that the sign determination value is negative (in the case of N), it can be determined that the turning direction of the previous speed command value and the current speed command value are different. In this case, since the rotational speed of the arm drive motor 6 is always “decelerate”, the time constant selector 3 selects the time constant for the deceleration state in step S8. On the other hand, when the sign of the sign determination value is positive (in the case of Y), the acceleration / deceleration determination processing unit 2 determines the sign of the change amount of the speed command value in step S15. When the sign of the amount of change is positive (in the case of Y), in step S6, the time constant selection unit 3 selects an acceleration state time constant. If the sign of the amount of change is negative (N), the time constant selection unit 3 selects the time constant for deceleration state in step S8.

  In step S4, if the absolute value is smaller than the determination value (N), the sign of the filter output value is determined in step S14. If there is a change in the sign of the filter output value (in the case of N), the process proceeds to step S6 and the acceleration time constant is selected. On the other hand, when there is no sign change in the filter output value (in the case of Y), the time constant selection unit 3 selects the current time constant in step S10.

  The series of operations (S1 to S15) is set as a control cycle, and the control of the arm driving motor 6 is performed by repeating this control cycle.

  As described above, when a command with a different turning direction is input, the rotational speed of the arm drive motor 6 is set to “decelerate”, and after the rotational speed of the arm drive motor 6 becomes 0 in step S14, the arm drive is performed. The rotation speed of the motor 6 can be switched to “acceleration”.

  Therefore, according to the second embodiment, the arm driving motor 6 of the present invention can be controlled with a simpler configuration.

  As described above, according to the control method of the arm drive motor of the present invention shown in the first and second embodiments, it is possible to realize the control for separately adjusting the response speed of the inverter in the acceleration state and in the deceleration state. In particular, for a command to change the turning direction abruptly, the time constant for acceleration state is selected when the motor for driving the arm accelerates, and the time constant for deceleration state is selected when the motor for driving the arm decelerates. This improves the workability and safety of the arm.

DESCRIPTION OF SYMBOLS 1 ... Operation lever 2 ... Acceleration / deceleration judgment processing part 3 ... Time constant for acceleration state, time constant selection part for deceleration state (time constant selection part)
4 ... Filter unit 5 ... Control unit 6 ... Electric motor for arm drive (electric motor)
7 ... Inverter 8 ... Filter time constant setting unit 9 ... Filter difference calculation unit (calculation unit)

Claims (7)

In a construction machine having an arm, an inverter that controls an electric motor that moves the arm,
An operating lever for commanding the turning direction and speed of the arm;
When a speed command value, which is an output signal of the operation lever, is detected at a predetermined fixed interval, and the amount of change in the speed command value is greater than a predetermined determination value, the input signal of the operation lever is An acceleration / deceleration determination processing unit for determining whether the command value is for accelerating or decelerating,
A time constant for acceleration state and a time constant for deceleration state are set separately, and one of the time constants for acceleration state is selected according to the determination processing signal of the acceleration / deceleration determination processing unit, The time constant selection part for deceleration state,
Based on the selected time constant signal, a filter unit that outputs a command value of the turning direction and speed of the motor as a filter output value,
The acceleration / deceleration determination processing unit
When the change amount is smaller than the determination value and the sign of the filter output value changes, it is determined that the arm is accelerated,
A control device for an electric motor for driving an arm of construction equipment, wherein a speed command value having a different turning direction of the arm is inputted at a predetermined interval, and the arm is judged to decelerate. 2. The control apparatus for an arm drive motor of a construction equipment according to claim 1, wherein the time constant is set so that a response speed at the time of acceleration is slower than a response speed at the time of deceleration. The selection unit determines the sign of the change amount when the absolute value of the change amount by the operation of the operation lever is larger than the determination value,
When the amount of change is greater than 0, select a time constant for acceleration state; when the amount of change is less than 0, select a time constant for deceleration state;
3. The control device for an arm drive motor for a construction machine according to claim 1, wherein the current time constant is selected when the absolute value of the change amount is smaller than the determination value. The inverter includes a filter difference calculation unit that calculates a difference between the speed command value and the filter output value,
4. The construction equipment according to claim 1, wherein the calculated filter difference is input to the acceleration / deceleration determination processing unit and is used for determination at the time constant switching time. 5. Control device for arm drive motor. The selection unit selects an acceleration state time constant when the absolute value of the amount of change due to operation of the operation lever is greater than the determination value, and when the amount of change is greater than 0 and the filter difference is greater than 0.
5. The control device for a motor for driving an arm of construction equipment according to claim 4, wherein a time constant for deceleration state is selected when the change amount and the filter difference are smaller than zero.   The construction value according to any one of claims 1 to 5, wherein the determination value is in a range of 1.5 to 2.0 times noise due to mechanical vibration of the operation lever. Arm drive motor control device. In a construction machine having an arm, an inverter that controls an electric motor that moves the arm,
A command input device for commanding the turning direction and speed of the arm with a pulse signal;
Detecting a speed command value that is an output signal of the command input device,
An acceleration / deceleration determination processing unit for determining whether an input signal of the command input device is a command value for accelerating or decelerating the arm;
A time constant for acceleration state and a time constant for deceleration state are set separately, and the time constant for acceleration state is selected according to the determination processing signal of the acceleration / deceleration determination processing unit, The time constant selection part for deceleration state,
Based on the selected time constant signal, a filter unit that outputs a command value of the turning direction and speed of the motor as a filter output value,
The acceleration / deceleration determination processing unit
If the command from the command input device does not change and the sign of the filter output value changes, it is determined that the arm is accelerated,
A control device for an electric motor for driving an arm of construction equipment, wherein when a speed command value having a different turning direction of the arm is inputted from the command input device, the arm is judged to decelerate.

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