JP2016194761A - Servo motor control device and collision detecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a servo motor control device with high collision detection accuracy.SOLUTION: A position command speed dimension signal output unit 110a of a servo motor control unit 10a outputs a speed dimension signal corresponding to a position command. A servo motor speed dimension signal output unit 120 outputs a speed dimension signal of a servo motor 20. A first collision detecting unit 130 detects an absolute value of speed deviation between the speed dimension signal output by the position command speed dimension signal output unit and the speed dimension signal output by the servo motor speed dimension signal output unit as a collision when the absolute value becomes a specific value or higher. A position command acceleration dimension conversion unit 140a converts the speed dimension signal related to the position command to an acceleration dimension signal and outputs it. A servo motor acceleration dimension conversion unit 150 outputs an acceleration dimension signal of the servo motor 20. A second collision detecting unit 160 detects an absolute value of acceleration deviation as a collision when the absolute value becomes a specific value or higher. A selecting unit 180 selects the first collision detecting unit 130 and the second collision detection unit 160 according to detecting method selection setting 191 of a parameter setting unit 190.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a servo motor control apparatus and a collision detection method, and more particularly to a servo motor control apparatus and a collision detection method including a servo motor that operates an operation target.

2. Description of the Related Art Conventionally, there is a technique for detecting a collision of an operation target such as a robot arm in a servo motor control apparatus.
For example, Patent Document 1 describes an actuator control device that controls an actuator having a moving body. The apparatus of Patent Document 1 includes a current detection unit that detects a value of a current flowing through a motor in an actuator while the actuator is being driven and the moving body moves from the end of acceleration to the start of deceleration, and a current detection unit. And a collision detecting means for detecting a collision of the moving body when the current value detected by the above exceeds a predetermined threshold value. That is, in the technique of Patent Document 1, a collision detection signal is output when the torque command value exceeds a threshold value.

JP 2014-87235 A

  However, the technique disclosed in Patent Document 1 has a problem that a collision cannot be detected when an unbalanced load is applied or during acceleration / deceleration. For this reason, the detection accuracy of the collision detection is not sufficient.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a servo motor control device that solves the above-described problems and increases the accuracy of collision detection.

The servo motor control device of the present invention is a servo motor control device including a servo motor that operates an operation target and a servo motor control unit that controls the servo motor according to a position command, and the servo motor control unit includes: Output by a position command speed dimension signal output unit that outputs a speed dimension signal corresponding to the position command, a servo motor speed dimension signal output unit that outputs a speed dimension signal of the servo motor, and a position command speed dimension signal output unit First collision detection that detects a collision when the absolute value of the speed deviation, which is a difference value between the speed dimension signal thus generated and the speed dimension signal output by the servo motor speed dimension signal output unit, exceeds a specific value And position command acceleration output by converting the speed dimension signal output from the position command speed dimension signal output unit into an acceleration dimension signal. An original conversion unit, a servo motor acceleration dimension conversion unit that converts the speed dimension signal output by the servo motor speed dimension signal output unit into an acceleration dimension signal, and the acceleration output by the position command acceleration dimension conversion unit A second collision detection unit that detects a collision when an absolute value of an acceleration deviation that is a difference value between the dimension signal and the acceleration dimension signal output by the servo motor acceleration dimension conversion unit is a specific value or more; A selection unit that selects the first collision detection unit and the second collision detection unit according to a specific parameter is provided.
With this configuration, in the position control, the first collision detection unit and the second collision detection unit can be appropriately selected in accordance with the application application and the like, and the accuracy of collision detection can be improved.

The servo motor control device of the present invention is a servo motor control device including a servo motor that operates an operation target and a servo motor control unit that controls the servo motor according to a speed command, and the servo motor control unit includes: A speed command speed dimension signal output unit that outputs a speed dimension signal corresponding to the speed command, a servo motor speed dimension signal output unit that outputs a speed dimension signal of the servo motor, and output by the speed command speed dimension signal output unit First collision detection that detects a collision when the absolute value of the speed deviation, which is a difference value between the speed dimension signal thus generated and the speed dimension signal output by the servo motor speed dimension signal output unit, exceeds a specific value And a speed command acceleration output by converting the speed dimension signal output by the speed command speed dimension signal output unit into an acceleration dimension signal. An original conversion unit, a servo motor acceleration dimension conversion unit that converts the speed dimension signal output by the servo motor speed dimension signal output unit into an acceleration dimension signal, and an acceleration output by the speed command acceleration dimension conversion unit A second collision detection unit that detects a collision when an absolute value of an acceleration deviation that is a difference value between the dimension signal and the acceleration dimension signal output by the servo motor acceleration dimension conversion unit is a specific value or more; A selection unit that selects the first collision detection unit and the second collision detection unit according to a specific parameter is provided.
With this configuration, in the speed control, the first collision detection unit and the second collision detection unit can be appropriately selected in accordance with the application application and the like, and the accuracy of collision detection can be improved.

In the servo motor control device of the present invention, the servo motor control unit detects a third collision as a collision when the absolute value of the acceleration dimension signal output by the servo motor acceleration dimension conversion unit exceeds a specific value. The selection unit also selects the third collision detection unit according to the specific parameter.
With this configuration, in a situation where acceleration / deceleration is slow, the accuracy of collision detection can be increased by comparing the acceleration dimension signal itself with a specific value.

In the servo motor control device of the present invention, the servo motor speed dimension signal output unit outputs a signal obtained by differentiating the position signal detected by a position detection sensor that detects the position of the servo motor as a speed dimension signal. It is characterized by.
By comprising in this way, a speed dimension signal can be easily obtained with a differentiator, and a structure can be simplified.

In the servo motor control device of the present invention, the servo motor speed dimension signal output unit outputs a speed estimation signal calculated by a speed observer that estimates a speed from an input signal to a model control target and an output signal of the control target. And output as a velocity dimension signal.
With this configuration, collision detection can be performed even in a configuration using an observer.

The servo motor control device according to the present invention includes a feedback loop for calculating a deviation between a signal obtained by multiplying a value of the position command by a proportional gain and a signal obtained by differentiating the position signal detected by the position detection sensor by a differential filter. The servo motor speed dimension signal output unit outputs the output signal of the differential filter arranged in the feedback loop as a speed dimension signal.
By comprising in this way, a calculation can be simplified and a structure can be simplified.

In the servo motor control device of the present invention, the first collision detection unit differentiates, instead of the speed deviation, a signal obtained by multiplying a value of the position command by a proportional gain and a position signal detected by the position detection sensor. A difference value from the received signal is calculated as a pseudo speed deviation, and when the absolute value of the pseudo speed deviation exceeds a specific value, it is detected as a collision.
By comprising in this way, a calculation can be simplified and a structure can be simplified.

In the servo motor control device of the present invention, the second collision detection unit calculates, as a pseudo acceleration deviation, a signal obtained by differentiating the pseudo speed deviation instead of the acceleration deviation, and the absolute value of the pseudo acceleration deviation is a specific value. When it becomes above, it detects as a collision, It is characterized by the above-mentioned.
By comprising in this way, a calculation can be simplified and a structure can be simplified.

In the servo motor control device of the present invention, the selection unit selects one of the first collision detection unit, the second collision detection unit, and the third collision detection unit, depending on the parameter set from the outside. It is characterized by selecting.
With such a configuration, a circuit suitable for collision detection from the outside can be set as needed, and the load for changing the circuit can be reduced and changed easily.

In the servo motor control device of the present invention, the selection unit is set from the outside with the specific value of the first collision detection unit, the specific value of the second collision detection unit, and the specific value of the third collision detection unit. It is characterized by that.
By configuring in this way, a specific value can be set as needed from the outside, and can be easily changed with little change load.

The servo motor control device according to the present invention is characterized in that the velocity dimension signal is a filter signal including an element having 1 / (τs + 1) as a transfer function as a control system model.
With this configuration, it is possible to include the elements of the control model in the filter, and it is possible to obtain a signal that is close to an actual signal in a pseudo manner.

The servo motor control device according to the present invention is characterized in that a cutoff frequency of the filter is set from the outside.
With this configuration, the change load is reduced, and the cut-off frequency can be selected easily and appropriately.

The collision detection method of the present invention is a collision detection method executed by a servo motor control device including a servo motor that operates an operation target and a servo motor control unit that controls the servo motor by a position command, A speed dimension signal corresponding to the position command is output, a speed dimension signal of the servo motor is output, and a difference between the output speed dimension signal corresponding to the position command and the output speed dimension signal of the servo motor A velocity deviation which is a value is calculated, an acceleration dimension signal corresponding to the position command is output, an acceleration dimension signal of the servo motor is output, and an acceleration dimension signal corresponding to the output position command is output. An acceleration deviation which is a difference value from the acceleration dimension signal of the servomotor is calculated, and the speed deviation and acceleration deviation selected by a specific parameter are calculated. If the absolute value of one is equal to or greater than a specific value, and detecting as a collision.
With this configuration, it is possible to appropriately select a collision detection method in accordance with the application purpose and the like, and to improve the accuracy of collision detection.

  According to the present invention, it is possible to provide a servo motor control device with high collision detection detection accuracy by selecting collision detection based on speed deviation and collision detection based on acceleration deviation based on specific parameters.

1 is a system configuration diagram of a servo motor control device according to an embodiment of the present invention. It is a block diagram which shows the control structure in case the servomotor control part shown in FIG. 1 performs position control. It is a block diagram which shows the control structure in case the servomotor control part shown in FIG. 1 performs speed control. It is a block diagram which shows the control structure containing the control system shown in FIG. 1 or FIG.

<Embodiment>
[Configuration of control system X]
With reference to FIG. 1, the structure of the control system X which concerns on embodiment of this invention is demonstrated. The control system X is a system for performing control in various devices such as a robot, a machine tool, a vehicle, a ship, an aircraft, and a factory plant.

  In addition, the control system X of the present embodiment includes a servo motor control device 1, an operation object 2, and a host device 3.

The servo motor control device 1 is a device that controls the servo motor 20 while adjusting the control amount in accordance with the position command or the speed command, and operates the operation target 2. In addition, the servo motor control device 1 detects a collision of the operation object 2.
As the collision detection, the servo motor control device 1 detects that the robot arm or the like has stopped due to contact with an obstacle or the like when performing position control based on a position command. Further, the servomotor control device 1 detects that the rotation has been stopped due to a missing tooth of a rotating member of a machine tool, a bearing failure, or the like when performing speed control based on a speed command.
The servo motor control device 1 is a hardware resource for executing the collision detection method according to the present embodiment.

  The motion object 2 is a member that is subject to motion control by the servo motor control device 1. The operation target 2 is, for example, an arm of an industrial robot, a rotating member of a machine tool, a vehicle wheel or gear or belt, a ship shaft, an aircraft propeller, a factory plant actuator, or the like.

  The host device 3 is an external device for controlling and managing various devices. Specifically, the host device 3 is, for example, a PLC (Programmable Logic Controller), an FC (Factory Computer), a server (Server), a PC (Personal Computer), or the like. The host device 3 executes an application (Application Program) for controlling and managing the servo motor control device 1. Accordingly, the host device 3 transmits a position command or a speed command to the servo motor control device 1 and receives various information from the servo motor control device 1. In addition, the host device 3 can acquire a user instruction and set various setting values in a parameter setting unit 190 (FIGS. 2 and 3) described later.

  The servo motor control device 1 includes a servo motor control unit 10, a servo motor 20, and a detection unit 30.

The servo motor control unit 10 controls the servo motor 20 according to a position command or a speed command from the host device 3. Specifically, the servo motor control unit 10 includes, for example, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a digital signal processor (DSP), a central processing unit (CPU), and a micro processing unit (MPU). And an analog or digital driver unit (amplifier) for supplying power to the servomotor 20 to drive it.
Here, as will be described later, the servo motor control unit 10 can change the configuration when performing position control based on a position command and when performing speed control based on a speed command by an application of the host device 3. Is possible.

  The servo motor 20 is an AC servo motor 20, a DC servo motor 20, a linear actuator, or the like. The servo motor 20 operates the operation target 2.

The detection unit 30 detects the position of the shaft or the like of the servo motor 20. Specifically, the detection unit 30 includes a position detection sensor that detects and outputs the position of the servo motor 20. This position detection sensor is, for example, a magnetic or optical encoder.
The output signal of the detection unit 30 is input to the servo motor control unit 10 and used for feedback control of position control and speed control.

In addition, each part mentioned later implement | achieved by the control calculating means of the servomotor control part 10 may be comprised with a specific digital circuit. In addition to the digital circuit, the circuit may be configured by an analog circuit, and the software is a hardware resource by developing a control program stored in a ROM (Read Only Memory) in a RAM (Random Access Memory) and executing it. It may be configured as a circuit executed in the above.
Further, a configuration in which a pseudo-differentiator is not used to obtain a motor speed dimension signal is also possible. In this case, as will be described later, control is performed by estimating the speed of the servo motor 20 based on the motion model of the motion object 2 by the observer 300 (FIG. 4).

[Configuration of Servo Motor Control Unit 10]
Next, a detailed control configuration of the servo motor control unit 10 of FIG. 1 will be described with reference to FIGS.
FIG. 2 shows a configuration of the servo motor control unit 10a in the case where position control of the position of the servo motor 20 is input and position control of the position of the servo motor 20 is executed to detect collision.

  The servo motor control unit 10a includes a position command speed dimension signal output unit 110a, a servo motor speed dimension signal output unit 120, a first collision detection unit 130, a position command acceleration dimension conversion unit 140a, a servo motor acceleration dimension conversion unit 150, a second A collision detection unit 160, a third collision detection unit 170, a selection unit 180, and a parameter setting unit 190 are included.

  The control system 100 includes a model of the operation target 2 and shows the entire control system 100 that performs control by feedback.

  The position command speed dimension signal output unit 110a receives a position command from the host device 3 or the like, and outputs a speed dimension signal corresponding to the position command.

Further, the position command speed dimension signal output unit 110 a includes a differentiator 111 and a filter 112.
The differentiator 111 is a pseudo-differentiator or the like that differentiates a position command and converts it into a velocity dimension.
The filter 112 is, for example, a primary IIR filter (Infinite Impulse Response Filter). Thereby, the filter 112 outputs a signal delayed in time. The filter 112 includes an element having 1 / (τs + 1) as a transfer function as the control system 100 model. Here, τ is a time constant, and s is a Laplace operator. Parameters such as the cut-off frequency of the filter 112 can be set from the outside, and specifically, set by the cut-off setting 193 of the parameter setting unit 190.
In this cutoff setting 193, the cutoff frequency of the filter may be calculated from the set value of the servo gain.
In addition, various filters other than the primary filter can be used as the filter 112.

The servo motor speed dimension signal output unit 120 outputs a speed dimension signal of the servo motor 20.
As an example, the servo motor speed dimension signal output unit 120 acquires the position signal of the servo motor 20 detected by the position detection sensor of the detection unit 30, differentiates it with a differentiator, and outputs it as a speed dimension signal. In this case, the servo motor speed dimension signal output unit 120 calculates a speed feedback value that is a differential value of the position feedback value obtained from the actual control system 100.
The servo motor speed dimension signal output unit 120 can calculate the speed dimension signal by other methods. A method for acquiring and calculating the velocity dimension signal will be described later.

  The first collision detection unit 130 receives a speed deviation that is a difference value between the speed dimension signal output from the position command speed dimension signal output unit 110a and the speed dimension signal output from the servo motor speed dimension signal output unit 120. Is done. The first collision detection unit 130 detects a collision when the input absolute value of the speed deviation exceeds a specific value. The first collision detection unit 130 outputs a collision detection signal when a collision is detected.

  The position command acceleration dimension conversion unit 140a converts the speed dimension signal output from the position command speed dimension signal output unit 110a into an acceleration dimension signal and outputs the acceleration dimension signal. Specifically, the position command acceleration dimension conversion unit 140a further differentiates the velocity dimension signal related to the input position command with a differentiator to convert it into an acceleration dimension, and outputs this as an acceleration dimension signal.

  The servo motor acceleration dimension conversion unit 150 converts the speed dimension signal of the servo motor 20 into an acceleration dimension signal and outputs the acceleration dimension signal. Specifically, as an example, the servo motor acceleration dimension conversion unit 150 further differentiates the speed dimension signal output from the servo motor speed dimension signal output unit 120 with a differentiator to convert it into an acceleration dimension, and converts the acceleration dimension signal into an acceleration dimension. Output as a dimension signal.

  The second collision detection unit 160 receives an acceleration deviation which is a difference value between the acceleration dimension signal output from the position command acceleration dimension conversion unit 140a and the acceleration dimension signal output from the servo motor acceleration dimension conversion unit 150. . Then, the second collision detection unit 160 detects a collision when the absolute value of the acceleration deviation exceeds a specific value. The second collision detection unit 160 outputs a collision detection signal when a collision is detected.

  The third collision detection unit 170 detects a collision when the absolute value of the acceleration dimension signal output by the servo motor acceleration dimension conversion unit 150 exceeds a specific value. The third collision detection unit 170 outputs a collision detection signal when a collision is detected.

  The selection unit 180 selects which of the first collision detection unit 130, the second collision detection unit 160, and the third collision detection unit 170 is used for collision determination by the detection method selection setting 191 of the parameter setting unit 190. The selection unit 180 outputs the collision detection signal of the selected unit to the host device 3 or the like.

  The parameter setting unit 190 mainly sets various settings and stores them in a non-temporary recording medium such as a RAM or an EEPROM. Each setting value of the parameter setting unit 190 can be set by an external device such as the host device 3. Each set value may be set with a dip switch or the like.

The parameter setting unit 190 includes a detection method selection setting 191, a specific value setting 192, and a cutoff setting 193.
The detection method selection setting 191 is a specific parameter setting that specifies whether the selection unit 180 sets collision detection by the first collision detection unit 130, the second collision detection unit 160, or the third collision detection unit 170. Information. In the application in which the servo motor 20 is operated at a normal speed, it is preferable that the first collision detection unit 130 using the speed deviation is selected as the specific parameter. In addition, as for the specific parameter, it is preferable to select the second collision detection unit 160 using the acceleration deviation in an application where acceleration / deceleration is fast. In addition, as the specific parameter, it is preferable to select the third collision detection unit 170 using acceleration feedback in an application where acceleration / deceleration is moderate.
Note that this specific parameter may be specified in a function format such as a specific mathematical model, a fuzzy function, or an artificial neural network, rather than just a numerical value.

  The specific value setting 192 is a specific value of the first collision detection unit 130, a specific value of the second collision detection unit 160, and a specific value of the third collision detection unit 170. As this specific value setting 192, a single value may be prepared and used by switching for each application. The specific value of the specific value setting 192 may be prepared for each of the first collision detection unit 130, the second collision detection unit 160, and the third collision detection unit 170.

  The cutoff setting 193 is a setting of the cutoff frequency of the filter 112. Since this cutoff frequency can be calculated from the set value of the servo gain, the cutoff frequency may be set by changing and setting the servo gain by the cutoff setting 193.

The first collision detection unit 130, the second collision detection unit 160, and the third collision detection unit 170 can also perform collision detection by other methods. Other collision detection methods will be described later.
A configuration in which the third collision detection unit 170 does not exist is also possible.

  Next, the configuration of the servo motor control unit 10b in the case of executing the speed control in which the speed command of the servo motor 20 is input and the speed of the servo motor 20 is output will be described with reference to FIG. In FIG. 2 and FIG. 3, the same code | symbol is attached | subjected to the same component.

  The servo motor control unit 10b includes a speed command speed dimension signal output unit 110b and a speed command acceleration dimension conversion unit 140b.

The speed command speed dimension signal output unit 110b receives a speed command from the host device 3 or the like, and outputs a speed dimension signal corresponding to the speed command.
At this time, the speed command speed dimension signal output unit 110b is not differentiated because the speed command is a value of the speed dimension, and is input to the filter 112 similar to that included in the position command speed dimension signal output unit 110a.

  The speed command acceleration dimension conversion unit 140b converts the speed dimension signal output from the speed command speed dimension signal output unit 110b into an acceleration dimension signal and outputs the acceleration dimension signal. This process is the same as that of the position command acceleration dimension conversion unit 140a.

[Configuration of Control System 100 Model]
Next, with reference to FIG. 4, the details when acquiring the velocity dimension signal, the acceleration dimension signal, and the like in the control system 100, other collision detection methods, and the like will be described using a model based on a state space representation in consideration of the internal state. .

The control system 100 performs model matching control in accordance with a desired transfer function (model) that is a transfer function having desired characteristics for appropriately controlling the servo motor 20 corresponding to the operation object 2.
This model can be expressed as m0 / (s ² + m1s + m0) where the Laplace operator is s. This model can be modified as follows, for example.

m0 / (s ² + m1s + m0) = ω1ω2 / (s + ω1) (s + ω2)

Here, ω1 and ω2 are the cut-off frequencies of the model, and the following relationship is established.

m0 = ω1ω2, m1 = ω1 + ω2 (1)

Note that desired control response characteristics can be obtained by setting ω1 and ω2 in accordance with the characteristics of the operation object 2 and the servo motor 20 and the purpose of control.

  The control system 100 includes a proportional gain element 200, an integral filter element 210, a motor gain element 220, a control target element 230 including a servo motor and an operation target, a differential filter element 240, a forward path 250, and a first feedback path 260. , And a second return path 270.

Here, a specific value including a specific gain of an amplifier (not shown) that supplies power to the servo motor 20 and a torque constant of the servo motor 20 is used as a value of the inertial moment of the operation object 2 and the servo motor 20 ( A value (gain) divided by inertia (inertia) is defined as K.
Further, a gain that is a value obtained by dividing a term related to the viscosity of the operation target 2 and the servo motor 20 by the inertia of the operation target 2 and the servo motor 20 is defined as p.
In this case, each element is represented as follows:

The proportional gain element 200 is m0.
The integral filter element 210 is a transfer function represented by (s ² + q1s + q0) / (s ² + a1s).
The motor gain element 220 is 1 / K.
A control target element 230 including a servo motor and an operation target indicates a control target and is a transfer function represented by K / (s ² + ps).
The differential filter element 240 is a transfer function represented by (b2s ² + b1s) / (s ² + q1s + q0).
The forward path 250 is a path from the input of the control system 100 to the output.
The first feedback path 260 is a first feedback loop from the output unit of the control system 100 toward the input side.
The second feedback path 270 is a second feedback loop from the output unit of the control system 100 toward the input side. Here, the second feedback path 270 calculates a deviation of a signal obtained by multiplying the value of the position command by a proportional gain. That is, the second feedback path 270 is a feedback loop that calculates a deviation between a signal obtained by multiplying the value of the position command by a proportional gain and a signal obtained by differentiating the position signal detected by the position detection sensor by the differential filter element 240. is there.

A1, b1, and b2 satisfy the following relationship.

a1 = q1 + m1-p (2)
b1 = q0 × m1 (3)
b2 = (q1-p) × (m1-p) + q0 (4)

Also, q0 and q1 described above are values that are arbitrarily set in order to appropriately control the operation target 2 and the servo motor 20.

  With such a configuration, the servo motor speed dimension signal output unit 120 selects any one of speed feedback (a), speed feedback (b), and speed feedback (c) shown in FIG. 4 as the speed dimension signal. It can be used to calculate and output the velocity dimension signal.

  As described above, the speed feedback (a) is a speed feedback value calculated by applying a position signal (position feedback value) of the servo motor 20 detected by the position detection sensor or the like of the detection unit 30 to the differentiator.

The speed feedback (b) is a speed estimation signal estimated by the observer 300. The observer 300 is a speed observer that estimates a speed based on an input signal to the controlled object of the model and an output signal of the controlled object. Specifically, the observer 300 estimates the gain K and p based on the input to the control target element 230 and the output from the control target element 230. At this time, the observer 300 may be configured to estimate the gain K by, for example, the least square method. In this case, if the gain K or p is known, the observer 300 can use the value. Further, when these values are unknown, the gains K and p are sequentially estimated at specific time intervals.
In addition, when not using speed feedback (b), the structure which does not use the observer 300 is also possible.

  Speed feedback (c) is an output signal of the differential filter element 240 of the second feedback path 270. That is, the velocity feedback (c) outputs the output signal of the differential filter arranged in the second feedback loop as a velocity dimension signal.

  Note that which speed feedback value the servo motor speed dimension signal output unit 120 uses can be set in the parameter setting unit 190.

  In addition, the first collision detection unit 130 simulates a difference value between a signal obtained by multiplying the position command value by a proportional gain and a signal obtained by differentiating the position signal detected by the position detection sensor, instead of the above speed deviation. It is also possible to calculate a speed deviation and use this instead of the speed deviation to detect a collision. That is, the first collision detection unit 130 calculates a pseudo speed deviation that is a difference value between the output value of the proportional gain element 200 and the output value of the differential filter element 240 of the second feedback path 270. In this case, the first collision detection unit 130 detects a collision when the calculated absolute value of the pseudo speed deviation exceeds a specific value.

  Similarly, the second collision detection unit 160 can also calculate, as a pseudo acceleration deviation, a signal obtained by differentiating the pseudo speed deviation with the differentiator 310 instead of the acceleration deviation. In this case, when the calculated absolute value of the pseudo acceleration deviation exceeds a specific value, it is detected as a collision. The third collision detection unit 170 can also perform collision detection using the pseudo acceleration deviation value.

[Effect of this embodiment]
With the configuration described above, the following effects can be obtained.
Conventionally, in the method of performing collision detection using torque as described in Patent Document 1, sufficient accuracy of collision detection cannot be obtained.
A servo motor control apparatus 1 according to an embodiment of the present invention is a servo motor control apparatus 1 including a servo motor 20 that operates an operation target and a servo motor control unit 10a that controls the servo motor 20 by a position command. The servo motor control unit 10a includes a position command speed dimension signal output unit 110a that outputs a speed dimension signal corresponding to the position command, a servo motor speed dimension signal output unit 120 that outputs a speed dimension signal of the servo motor 20, The absolute value of the speed deviation, which is the difference between the speed dimension signal output by the position command speed dimension signal output unit 110a and the speed dimension signal output by the servo motor speed dimension signal output unit 120, is equal to or greater than a specific value. The first collision detection unit 130 that detects the collision and the speed output by the position command speed dimension signal output unit 110a. A position command acceleration dimension conversion unit 140a that converts the dimension signal into an acceleration dimension signal and outputs the acceleration dimension signal; and a servo motor acceleration dimension that converts the speed dimension signal output by the servo motor speed dimension signal output unit 120 into an acceleration dimension signal and outputs the acceleration dimension signal. The absolute value of the acceleration deviation, which is the difference value between the acceleration dimension signal output by the conversion unit 150 and the position command acceleration dimension conversion unit 140a, and the acceleration dimension signal output by the servo motor acceleration dimension conversion unit 150 is greater than or equal to a specific value. The second collision detection unit 160 that detects a collision, the first collision detection unit 130, and the second collision detection unit 160 are selected by the detection method selection setting 191 of the parameter setting unit 190; It is characterized by providing.
By configuring in this way, the first collision detection unit 130 and the second collision detection unit 160 can be appropriately selected and used in accordance with the application purpose and the like. Here, the first collision detection unit 130 can detect the collision with higher accuracy than the case of using the position deviation or the torque. Further, the second collision detection unit 160 can detect the collision with higher accuracy in a situation where the acceleration / deceleration of the servo motor 20 is fast. For this reason, the detection accuracy of collision detection can be improved by making these selectable by a specific parameter corresponding to the application.
Further, in the technique of Patent Document 1, a collision could not be detected at the time of acceleration / deceleration. However, this can be achieved by selecting the second collision detection unit 160.

The servo motor control device 1 according to the embodiment of the present invention includes a servo motor 20 that operates an operation target and a servo motor control unit 10b that controls the servo motor 20 according to a speed command. The servo motor control unit 10b includes a speed command speed dimension signal output unit 110b that outputs a speed dimension signal corresponding to the speed command, and a servo motor speed dimension signal output unit 120 that outputs a speed dimension signal of the servo motor 20. The absolute value of the speed deviation, which is the difference between the speed dimension signal output by the speed command speed dimension signal output unit 110b and the speed dimension signal output by the servo motor speed dimension signal output unit 120, is greater than or equal to a specific value. The first collision detection unit 130 that detects a collision and the speed command speed dimension signal output unit 110b. A speed command acceleration dimension conversion unit 140b that converts the converted speed dimension signal into an acceleration dimension signal and outputs the acceleration dimension signal; and a servo motor that converts the speed dimension signal output by the servo motor speed dimension signal output unit 120 into an acceleration dimension signal and outputs the acceleration dimension signal The absolute value of the acceleration deviation, which is the difference value between the acceleration dimension signal output by the acceleration dimension conversion unit 150 and the speed command acceleration dimension conversion unit 140b, and the acceleration dimension signal output by the servo motor acceleration dimension conversion unit 150 is specified. A selection unit that selects the second collision detection unit 160 to detect as a collision, the first collision detection unit 130, and the second collision detection unit 160 by the detection method selection setting 191 of the parameter setting unit 190 when the value exceeds the value. 180.
By configuring in this way, it is possible to improve the accuracy of collision detection as with the servo motor control unit 10a described above. Moreover, since the differential element can be reduced if the speed command is used, the portion can be simplified.
Conventionally, a technique for detecting a collision only with a position command cannot detect a collision during speed control. In contrast, the servo motor control unit 10b of the present embodiment can detect a collision with high accuracy even during speed control.

In addition, the servo motor control unit 10 according to the embodiment of the present invention detects the third collision as a collision when the absolute value of the acceleration dimension signal output from the servo motor acceleration dimension conversion unit 150 exceeds a specific value. The detection unit 170 is further provided, and the selection unit 180 selects the third collision detection unit 170 according to a specific parameter.
With this configuration, it is possible to compare the dimension signal itself, which is the acceleration value, with the specific value, and to improve the accuracy of collision detection in a situation where acceleration / deceleration is moderate.

In the servo motor control device 1 according to the embodiment of the present invention, the servo motor speed dimension signal output unit 120 outputs a signal obtained by differentiating the position signal detected by the position detection sensor that detects the position of the servo motor 20. And output as a velocity dimension signal.
By comprising in this way, a speed dimension signal can be easily obtained with a differentiator. For this reason, a structure can be simplified and cost can be reduced.

In the servo motor control device 1 according to the embodiment of the present invention, the servo motor speed dimension signal output unit 120 is an observer 300 that estimates the speed based on the input signal to the control target of the model and the output signal of the control target. The calculated speed estimation signal is output as a speed dimension signal.
With this configuration, even in a configuration using the observer 300 instead of the servo motor speed dimension signal output circuit 120, collision detection can be performed.

In addition, the servo motor control device 1 according to the embodiment of the present invention includes a signal obtained by multiplying the value of the position command by a proportional gain, a signal obtained by differentiating the position signal detected by the position detection sensor by the differential filter element 240, and The servo motor speed dimension signal output unit 120 outputs the output signal of the differential filter element 240 arranged in the second feedback path 270 as a speed dimension signal. It is characterized by doing.
With this configuration, the output in the feedback can be used as a speed dimension signal as it is, so that the calculation can be simplified, the configuration can be simplified, and the cost can be reduced.

In the servo motor control device 1 according to the embodiment of the present invention, the first collision detection unit 130 is detected by the position detection sensor and a signal obtained by multiplying the position command value by a proportional gain instead of the speed deviation. A difference value from the signal obtained by differentiating the position signal is calculated as a pseudo speed deviation, and when the absolute value of the pseudo speed deviation exceeds a specific value, it is detected as a collision.
With this configuration, the pseudo speed deviation, which is a value during the calculation of the transfer function, can be used as a speed dimension signal as it is, so that the calculation can be simplified, the configuration can be simplified, and the cost can be reduced.

Further, in the servo motor control device 1 according to the embodiment of the present invention, the second collision detection unit 160 calculates a signal obtained by differentiating the pseudo speed deviation as the pseudo acceleration deviation instead of the acceleration deviation, and calculates the pseudo acceleration deviation. When the absolute value exceeds a specific value, it is detected as a collision.
With this configuration, the pseudo acceleration deviation can be used as an acceleration dimension signal as it is simply by differentiating the value in the middle of the transfer function calculation, simplifying the calculation, simplifying the configuration, and reducing the cost. Can be reduced.

In the servo motor control device 1 according to the embodiment of the present invention, the selection unit 180 selects which of the first collision detection unit 130, the second collision detection unit 160, and the third collision detection unit 170, The selection is made by parameters set from the outside.
By configuring in this way, it is possible to set at any time from the outside which circuit is suitable for detecting a collision. For this reason, there is little change load, and the collision detection method can be easily changed.

Further, in the servo motor control device 1 according to the embodiment of the present invention, the selection unit 180 has the specific value of the first collision detection unit 130, the specific value of the second collision detection unit 160, and the specification of the third collision detection unit 170. The value is set from the outside.
With this configuration, the specific value can be set from outside as needed. For this reason, it is possible to change the specific value as a collision detection threshold with a small change load.

In the servo motor control device 1 according to the embodiment of the present invention, the velocity dimension signal is a signal of the filter 112 including an element having 1 / (τs + 1) as a transfer function as a model of the control system 100. And
With this configuration, the filter 112 can include elements of the control model, and the position command value or the speed command value can be used as input to the actual control target. As a result, it is possible to obtain a pseudo signal close to an actual signal, and to detect a collision with higher accuracy than in the past.

Further, the servo motor control device 1 according to the embodiment of the present invention is characterized in that the filter 112 has a cutoff frequency set from the outside.
By configuring in this way, the cut-off frequency can be set from time to time, so that the change load is reduced. Further, the cut-off frequency can be easily selected as appropriate in accordance with the servo motor 20. As described above, this cutoff frequency may be calculated from the servo gain setting value.

In addition, the collision detection method according to the embodiment of the present invention includes a servo motor control device 1 including a servo motor 20 that operates an operation target and a servo motor control unit 10 that controls the servo motor 20 according to a position command. A collision detection method to be executed, wherein a speed dimension signal corresponding to the position command is output, a speed dimension signal of the servo motor 20 is output, and a speed dimension signal corresponding to the output position command is output. A speed deviation which is a difference value from the speed dimension signal of the servo motor 20 is calculated, an acceleration dimension signal corresponding to the position command is output, an acceleration dimension signal of the servo motor 20 is output, and output An acceleration deviation which is a difference value between the acceleration dimension signal corresponding to the position command and the output acceleration dimension signal of the servo motor 20 is calculated and specified. When the absolute value of either the speed deviation or acceleration deviation selected by the parameter exceeds a specific value, it is detected as a collision. The collision detection method can be appropriately selected and used. For this reason, the accuracy of collision detection can be increased.

[Other Embodiments]
In the above-described embodiment, the example in which the collision of the servo motor 20 is detected has been described.
However, the collision detection method of the present invention can also be used for applications such as detecting a state in which the control system 100 becomes unstable and causes vibrations. As a result, the control of the servo motor 20 can be stabilized against disturbances and the like.

In the above-described embodiment, the first collision detection unit 130, the second collision detection unit 160, and the third collision detection unit 170 obtain the absolute value of the speed deviation, the absolute value of the acceleration deviation, and the absolute value of the acceleration dimension signal. It was described that collision was detected in comparison with a specific value.
However, after inputting the absolute value of the speed deviation, the absolute value of the acceleration deviation, or the absolute value of the acceleration dimension signal to the selection circuit 180 and selecting which absolute value to use by the detection method selection setting 191, A configuration may be adopted in which a collision is detected by a comparator or the like when the value exceeds a specific value set in the specific value setting 192 of the parameter setting unit 190.
With this configuration, the output of collision detection can be processed with one comparator, the circuit scale can be reduced, and the cost can be reduced.

  Note that the configuration and operation of the above-described embodiment are examples, and it is needless to say that the configuration and operation can be appropriately changed and executed without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Servo motor control apparatus 2 Operation | movement object 3 Host apparatus 10, 10a, 10b Servo motor control part 20 Servo motor 30 Detection part 100 Control system 110a Position command speed dimension signal output part 110b Speed command speed dimension signal output part 111,310 Differentiation 112 Filter 120 Servo motor speed dimension signal output unit 130 First collision detection unit 140a Position command acceleration dimension conversion unit 140b Speed command acceleration dimension conversion unit 150 Servo motor acceleration dimension conversion unit 160 Second collision detection unit 170 Third collision detection unit 180 selection unit 190 parameter setting unit 191 detection method selection setting 192 specific value setting 193 cut-off setting 200 proportional gain element 210 integral filter element 220 motor gain element 230 control target element 240 differential filter element 250 forward path 260 first feedback path 270 Second feedback path 300 observer X control system

Claims (13)

A servo motor control device including a servo motor that operates an operation target and a servo motor control unit that controls the servo motor according to a position command,
The servo motor controller is
A position command speed dimension signal output unit that outputs a speed dimension signal corresponding to the position command;
A servo motor speed dimension signal output unit that outputs a speed dimension signal of the servo motor;
The absolute value of the speed deviation, which is the difference between the speed dimension signal output by the position command speed dimension signal output unit and the speed dimension signal output by the servo motor speed dimension signal output unit, is greater than or equal to a specific value. A first collision detection unit for detecting a collision;
A position command acceleration dimension converter that converts the speed dimension signal output by the position command speed dimension signal output unit into an acceleration dimension signal and outputs the acceleration dimension signal;
A servo motor acceleration dimension converter that converts the speed dimension signal output by the servo motor speed dimension signal output unit into an acceleration dimension signal and outputs the acceleration dimension signal;
When the absolute value of the acceleration deviation that is the difference value between the acceleration dimension signal output by the position command acceleration dimension conversion unit and the acceleration dimension signal output by the servo motor acceleration dimension conversion unit is equal to or greater than a specific value, A second collision detector for detecting as a collision;
A servo motor control device comprising: a selection unit that selects the first collision detection unit and the second collision detection unit according to a specific parameter. A servo motor control device including a servo motor that operates an operation target and a servo motor control unit that controls the servo motor according to a speed command,
The servo motor controller is
A speed command speed dimension signal output unit that outputs a speed dimension signal corresponding to the speed command;
A servo motor speed dimension signal output unit that outputs a speed dimension signal of the servo motor;
The absolute value of the speed deviation, which is the difference value between the speed dimension signal output by the speed command speed dimension signal output unit and the speed dimension signal output by the servo motor speed dimension signal output unit, is equal to or greater than a specific value. A first collision detection unit for detecting a collision;
A speed command acceleration dimension converter that converts the speed dimension signal output by the speed command speed dimension signal output unit into an acceleration dimension signal and outputs the acceleration dimension signal;
A servo motor acceleration dimension converter that converts the speed dimension signal output by the servo motor speed dimension signal output unit into an acceleration dimension signal and outputs the acceleration dimension signal;
When the absolute value of the acceleration deviation that is the difference value between the acceleration dimension signal output by the speed command acceleration dimension conversion unit and the acceleration dimension signal output by the servo motor acceleration dimension conversion unit is a specific value or more, A second collision detector for detecting as a collision;
A servo motor control device comprising: a selection unit that selects the first collision detection unit and the second collision detection unit according to a specific parameter. The servo motor controller is
When the absolute value of the acceleration dimension signal output by the servo motor acceleration dimension conversion unit is a specific value or more, further comprising a third collision detection unit for detecting as a collision,
The servo motor control device according to claim 1, wherein the selection unit also selects the third collision detection unit according to the specific parameter. The servo motor speed dimension signal output unit is
The servomotor according to any one of claims 1 to 3, wherein a signal obtained by differentiating a position signal detected by a position detection sensor that detects a position of the servomotor is output as a velocity dimension signal. Control device. The servo motor speed dimension signal output unit is
4. A speed estimation signal calculated by a speed observer that estimates a speed from an input signal to a model control target and an output signal of the control target is output as a speed dimension signal. 2. The servo motor control device according to claim 1. A feedback loop for calculating a deviation between a signal obtained by multiplying a value of the position command by a proportional gain and a signal obtained by differentiating the position signal detected by the position detection sensor by a differential filter;
The servo according to any one of claims 1 to 3, wherein the servo motor speed dimension signal output unit outputs an output signal of the differential filter disposed in the feedback loop as a speed dimension signal. Motor control device. The first collision detection unit
Instead of the speed deviation, a difference value between a signal obtained by multiplying the value of the position command by a proportional gain and a signal obtained by differentiating the position signal detected by the position detection sensor is calculated as a pseudo speed deviation. The servo motor control device according to claim 4, wherein a collision is detected when the absolute value of the speed deviation exceeds a specific value. The second collision detector is
A signal obtained by differentiating the pseudo speed deviation instead of the acceleration deviation is calculated as a pseudo acceleration deviation, and a collision is detected when the absolute value of the pseudo acceleration deviation exceeds a specific value. 8. The servo motor control device according to 7. The selection unit selects one of the first collision detection unit, the second collision detection unit, and the third collision detection unit according to the parameter set from the outside. The servo motor control device according to any one of 3 to 8. The specific value of the first collision detection unit, the specific value of the second collision detection unit, and the specific value of the third collision detection unit are set from the outside in the selection unit. 4. The servo motor control device according to claim 1. The servo motor control device according to any one of claims 1 to 10, wherein the velocity dimension signal is a signal of a filter including an element having 1 / (τs + 1) as a transfer function as a control system model. . The servo motor control device according to claim 11, wherein a cutoff frequency of the filter is set from the outside. A collision detection method executed by a servo motor control device including a servo motor that operates an operation target and a servo motor control unit that controls the servo motor according to a position command,
Output velocity dimension signal corresponding to the position command,
Output the servo motor speed dimension signal,
Calculating a speed deviation which is a difference value between the output speed dimension signal corresponding to the position command and the output speed dimension signal of the servo motor;
Output an acceleration dimension signal corresponding to the position command,
Output the acceleration dimension signal of the servo motor,
Calculating an acceleration deviation that is a difference value between the output acceleration dimension signal corresponding to the position command and the output acceleration dimension signal of the servo motor;
A collision detection method comprising: detecting a collision when an absolute value of any one of the speed deviation and the acceleration deviation selected by a specific parameter exceeds a specific value.

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