JPH10235581A - Control module and control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily add or eliminate a force control function by providing a control module with a function replacing a control mode with a control mode which is different from this control mode when the module is connected to a controller. SOLUTION: A robot controller 13 takes in positional data from an encoder mounted on the tip part of a manipulator 11 of an industrial robot 10, drives the servo motor of each joint of the manipulator 11 based on a difference of this positional data and a target location and performs a positional control for the manipulator 11, when the controller 13 independently performs a control operation. When a force control module 1 is connected to the robot controller 13, the force control module 1 transmits a force control mode signal to the robot controller 13 and transmits s force control program stored in a program memory 2-1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control module provided with a force control function for an industrial robot to perform work processing such as assembling and processing of products using force control, and a control module using the control module. About the system.

[0002]

2. Description of the Related Art At present, industrial robots are mainly driven by position control using a servo controller. Many of the position control controllers include an input / output interface for exchanging with externally connected devices such as a solenoid valve and a limit switch, and a communication interface represented by RS232C.

[0003] As a control method of an industrial robot, besides position control, there is a control method called force control for controlling a contact force generated at the time of assembling and processing a product or the like. Normal,
In this force control method, a force sensor is attached to a robot list to detect a contact force with a product, and this detection data is sent to a robot controller, subjected to necessary arithmetic processing, and used for control.

On the other hand, a commercially available servo controller has a problem that it cannot perform force control because there is no interface function for the force sensor as described above. In contrast,
The force control robot uses a dedicated robot controller capable of performing force control. Such a dedicated robot controller includes an analog / digital conversion unit for taking in detection data measured by a force sensor and an input / output interface.

However, in a dedicated robot controller, force control requires a larger amount of calculation than position control. Therefore, when high-speed processing is required, the central processing unit needs to perform operations that do not require force control. Sometimes some functions of expensive controllers are wasted without being executed.

[0006] From such a situation, it is described in, for example, the 11th Robotics Society of Japan Academic Lecture (Study of Robot Controllers Emphasizing Modularity (1)-(3), November 12-14, 1993). As described above, technical research is being conducted to block some of the controllers so that each module can be used as a component.

That is, in this technique, for example, the function of a controller is separated into a motion control block, a path generation block, a sensor processing block, and the like, and a processor is mounted on each of these processing systems.

However, this controller uses a VM
A research controller that requires an E-bus and network, and cannot be used immediately as an industrial controller. In addition, since the force control is included in, for example, a motion control system, only the force control function cannot be handled as a module.

[0009]

As described above, the force control of the dedicated robot controller requires a large amount of computation as compared with the position control. Therefore, when high-speed processing is required, the force control is not required. Sometimes some functions of expensive controllers are wasted.

[0010] Under such circumstances, even if the functions of the controller are separated into, for example, a motion control block, a path generation block, and a sensor processing block, the research controller cannot be used immediately as an industrial controller.

An object of the present invention is to provide a control module which can easily add or remove a force control function. Another object of the present invention is to provide a control system capable of easily adding or deleting a force control function by connecting or disconnecting a position control controller.

[0012]

According to the first aspect of the present invention, when a control target is connectable to and disconnectable from a controller controlled by a first control mode and is connected to the controller, the first control is performed. The control module has a function of replacing a mode with a second control mode different from the first control mode.

With such a control module, the controller normally controls the control target in the first control mode. When a control module is connected to the controller, the control module replaces the first control mode with a second control mode different from the first control mode, and controls the control target through the controller according to the second control mode.

According to a second aspect, in the control module according to the first aspect, the control module replaces the position control mode with the force control mode. According to a third aspect, in the control module according to the first aspect, data measured by a force sensor attached to a control target is captured,
2. A process for generating a trajectory of a control object using this data is replaced from a position control mode to a force control mode.
It is a control module of description.

According to a fourth aspect of the present invention, in a control system for controlling the position of a controlled object by a controller for position control, a force sensor attached to the controlled object can be connected to and disconnected from the controller, and can be connected to and disconnected from the controller. And a control module that captures data measured by the force sensor and replaces a process of generating a trajectory of a control target using the data from the position control mode to the force control mode. .

With such a control system, usually,
The controller controls the control target in the position control mode. When a control module is connected to the controller, the control module replaces the position control mode with the force control mode, and controls the control target through the controller according to the force control mode.

According to a fifth aspect of the present invention, in the control module according to the fourth aspect, there is provided a function of storing a process for generating the replaced trajectory so that the controller can return to the position control mode.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of the force control module. This force control module 1 has a CP
A U board 2 is provided, and an AD converter 4 is connected to the CPU board 2 via an I / O board 3.

The CPU board 2 includes a plurality of interfaces (I / Fs) 5-1 to 5-n which can be freely connected to and disconnected from an external robot controller and communicate with the external robot controller. It is connected.

The A / D converter 4 can be connected to and disconnected from an external force sensor (or torque sensor).
An interface (I / F) 6 for taking in an analog detection signal output from the force sensor is connected.

The CPU board 2 has a function of performing arithmetic processing and external communication. The CPU board 2 is provided with a program memory 2-1 for storing a force control program for performing force control. ing.

When connected to a robot controller, the CPU board 2 transmits a force control mode signal and a force control program to the robot controller,
In addition, the robot controller captures detection signals from force sensors attached to industrial robots that assemble or process products, and uses this detection signal to generate the trajectory of the industrial robot using the position control mode. Has a function of replacing the control mode with the force control mode.
That is, the CPU board 2 calculates the following control formula for generating a trajectory in the position control mode in the robot controller.

[0023]

(Equation 1) Control formula for trajectory generation by force control mode

[0024]

(Equation 2) Has the function of replacing However,

[0025]

(Equation 3) It is.

Here, the CPU board 2 has a function for calculating the control equation (2) for generating a trajectory in the force control mode by calculation, or a term K for a force error in the control equation (2).
_v * e _f only has a function of obtaining and processing.

When replacing the process of generating the trajectory of the industrial robot from the position control mode to the force control mode, the CPU board 2 reads the value from the encoder of each joint in the industrial robot. It has a function that does not change processes other than trajectory generation, such as processes for performing servo control of each servomotor.

The power control module 1 is provided with a DC power supply 7 for supplying power to each of the boards 1 to 6. Next, a control system to which the force control module is applied will be described.

FIG. 2 is a configuration diagram of such a control system. The industrial robot 10 performs, for example, assembly and processing of a product, and includes an articulated manipulator 11.

The list section of the industrial robot 10 includes:
A force sensor 12 is attached. This force sensor 12
Has a function of measuring the contact force and outputting a detection signal when assembling or processing a product by the industrial robot 10.

The robot controller 13 takes in the position data of the tip of the manipulator from an encoder attached to the industrial robot 10, and controls a servo motor for driving each joint of the manipulator 11 based on the difference between the position data and the target position. It has the function of servo control.

The robot controller 13 has an interface (I / F) 13-1 that can be connected to and disconnected from the force control module 1, and receives a force control mode signal from the force control module 1. The control mode is shifted to the control mode, and the control program of the process for generating the trajectory of the industrial robot 10 in the force control mode determined by the calculation process of the force control module 1 and the force control program transmitted from the force control module 1 (expression) (2)) or receiving section K _v * e _f error of the force in the same controlled, a manipulator 1 on the basis of such these force control program and the controlled
1 has a function of servo-controlling the servomotor of each joint in the force control mode.

The force control module 1 and the robot controller 13 are connected via a cable. Next, the operation of the control system to which the force control module configured as described above is applied will be described.

If the robot controller 13 operates independently, the robot controller 13 of the industrial robot 10
The position data is fetched from an encoder attached to the tip of the manipulator, and the servomotors of the respective joints of the manipulator 11 are driven based on the difference between the position data and the target position to control the position of the manipulator 11.

On the other hand, when the force control module 1 is connected to the robot controller 13, the force control module 1
A force control mode signal is transmitted to the robot controller 13 and a force control program stored in the program memory 2-1 is transmitted.

When the robot controller 13 receives the force control mode signal, the robot controller 13 shifts to the force control mode, and executes the process for generating the trajectory of the industrial robot 10 from the position control mode in the force control program to be executed. Replace with mode.

Subsequently, after connection with the robot controller 13, the force control module 1
An operation of receiving an encoder signal, a link parameter (length of each link), and matrix data (a coordinate transformation matrix of the industrial robot 10 and physical parameters such as mass of the industrial robot 10) from an encoder attached to the tip of the manipulator 11 from 3. Run.

Thereafter, the force control module 1 receives an encoder signal from an encoder attached to the tip of the manipulator 11 through the robot controller 13 at every control sampling time.

The force control module 1 takes in a contact force detection signal measured by the force sensor 12 when assembling or processing a product through the interface 6, and converts the detection signal into a digital signal by the A / D board 14. Then, the data is taken into the CPU board 2 through the I / O board 3.

If the detection signal output from the force sensor 12 is digital, the I / O
It is taken into the CPU board 2 through the board 3. And
The CPU board 2 replaces the process of generating the trajectory of the industrial robot 10 using the detection signal of the force sensor 12 from the position control mode to the force control mode, and performs coordinate transformation and gravity compensation using a coordinate transformation matrix and physical parameters. performed such, it can be processed executables, for example, the error of the force in the above formula (2) of the robot controller 13 K _v
* Performs arithmetic processing up to _f .

On the other hand, the robot controller 13, the force control module transmitted force control program 1, the error term K _v * e _f force in the force control mode determined by the calculation of the force control module 1 The servomotor of each joint of the manipulator 11 is servo-controlled in the force control mode based on the received power control program and the control formulas.

At this time, the robot controller 13
When replacing the process of generating the trajectory of the industrial robot 10 from the position control mode to the force control mode, the process of reading a value from the encoder of each joint in the industrial robot 10 and the servo control of each servo motor in the industrial robot 10 are performed. Processes other than trajectory generation, such as the process to be performed, are not changed.

The CPU board 2 or the robot controller 13 executes a process for generating the replaced trajectory.
It is stored so that the robot controller 13 can return to the position control mode.

Thereafter, when eliminating the force control mode, the force control module 1 is disconnected from the robot controller 13. Accordingly, when the robot controller 13 detects that the force control module 1 has been disconnected, the robot controller 13 returns to the position control trajectory generation process that has been retracted.

As described above, in the first embodiment, when the force control module 1 is connected to the robot controller 13, the process of generating the trajectory of the industrial robot 1 by the force control module 1 is performed in the position control mode. To the force control mode, the data measured by the force sensor 12 is taken in, and the industrial robot 1 is controlled based on this data.
Connect the force control module 1 as necessary to
Force control mode can be added or deleted.

Even when the robot controller 13 does not have a force control program, the force control is realized by transmitting the force control program stored in the program memory 2-1 of the force control module 1 to the robot controller 13. it can.

Further, the force sensor 1 in the force control module 1
2, the robot controller 13 can execute the processing as it is, for example, the above equation
Because performs arithmetic processing up section K _v * e _f error of the force in (2), it is possible to reduce the load of the robot controller 13 side.

A plurality of interfaces 5-1 to 5-n
, A plurality of robot controllers can be connected, and a single force control module 1 can drive and control a plurality of industrial robots in a force control mode. (2) Next, a second embodiment of the present invention will be described.
The same parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 3 is a configuration diagram of a control system to which the force control module 1 is applied. This control system has a configuration in which a force sensor 12 is attached to a work fixing jig 20.

With this configuration, when the force control module 1 is connected to the robot controller 13, the force control module 1 transmits a force control mode signal to the The force control program stored in the memory 2-1 is transmitted.

When the robot controller 13 receives the force control mode signal, the robot controller 13 shifts to the force control mode, and executes the process for generating the trajectory of the industrial robot 10 from the position control mode in the force control program to be executed. Replace with mode.

The force control module 1 includes a work fixing jig 2
The pressure on the work measured by the force sensor 12 mounted on the sensor board 0 is detected, the detection signal is taken in through the interface 6, converted to digital by the A / D board 14, and sent to the CPU board 2 through the I / O board 3. take in.

The CPU board 2 includes a force sensor 12
The process of generating the trajectory of the industrial robot 10 using the detection signals of the above is replaced from the position control mode to the force control mode, and coordinate conversion and gravity compensation are performed using a coordinate conversion matrix and physical parameters. format that can be executed directly process, for example, performs arithmetic processing up section K _v * e _f error of the force in the above formula (2).

On the other hand, the robot controller 13, the force control module 1 transmitted force control program from the force in the force control mode determined by the calculation of the force control module 1 to the section K _v * e _f error The servomotor of each joint of the manipulator 11 is servo-controlled in the force control mode based on the received power control program and the control formulas.

As described above, according to the second embodiment, the force sensor 12 is attached to the work fixing jig 20, and it goes without saying that the same effect as that of the first embodiment can be obtained. . (3) Next, a third embodiment of the present invention will be described.
The same parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4 is a configuration diagram of a control system to which the force control module 1 is applied. This control system includes a John Stick 21 for remotely controlling the industrial robot 10.
To which a force sensor 12 is attached.

With such a configuration, when the force control module 1 is connected to the robot controller 13, the force control module 1 transmits a force control mode signal to the The force control program stored in the memory 2-1 is transmitted. Thereby, the robot controller 13
Shifts to the force control mode, and replaces the process of generating the trajectory of the industrial robot 10 from the position control mode to the force control mode in the executed force control program.

The force control module 1 includes a joystick 2
1, the pressure measured by the force sensor 12 attached to the sensor 1 is detected, the detected signal is taken in through the interface 6, and the digital signal is converted by the A / D board 14,
It is taken into the CPU board 2 through the / O board 3.

The CPU board 2 includes a force sensor 12
The process of generating the trajectory of the industrial robot 10 using the detection signals of the above is replaced from the position control mode to the force control mode, and coordinate conversion and gravity compensation are performed using a coordinate conversion matrix and physical parameters. format that can be executed directly process, for example, performs arithmetic processing up section K _v * e _f error of the force in the above formula (2).

[0060] The robot controller 13 receives a term K _v * e _f error of the force in the transmitted force control program, obtained by the arithmetic processing of the force control module 1 Power control mode from the force control module 1 , The manipulator 1 based on the force control program and the control formula thereof.
The servo motor of each joint 1 is servo-controlled in the force control mode.

As described above, according to the third embodiment, it goes without saying that the same effects as those of the first embodiment can be obtained. (4) Next, a fourth embodiment of the present invention will be described.
The same parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 5 is a configuration diagram of a control system to which the force control module 1 is applied. In this control system, two industrial robots 10 and 22 are installed. These industrial robots 10 and 22 include manipulators 11 and 23, respectively, and perform operations such as processing on the work 23 on the work fixing jig 20.

Further, these industrial robots 10 and 22
The servo control is performed by the robot controllers 13 and 24, respectively. These robot controllers 13, 2
Reference numeral 2 denotes a servo motor which takes in position data of the tip of the manipulator from each encoder attached to the industrial robots 10 and 22, and drives each joint of the manipulators 11 and 23 based on a difference between the position data and a target position. Has the function of servo-controlling.

The robot controllers 13, 2
4 includes interfaces 13-1 and 24-1 that can be freely connected to and disconnected from the force control module 1, respectively, and when a force control mode signal from the force control module 1 is received, the mode shifts to the force control mode, and the force control mode is changed. The force control program transmitted from the module 1, the control formula (formula (2)) of the process for generating the trajectory of the industrial robot 10 in the force control mode determined by the arithmetic processing of the force control module 1, or the same control formula receives the section K _v * e _f of error of forces in,
It has a function of servo-controlling the servomotors of the joints of the manipulators 11 and 23 in the force control mode based on these force control programs and control formulas.

With such a configuration, when the force control module 1 is connected to the two robot controllers 13 and 24, the force control module 1 sends a force control mode signal to the robot controllers 13 and 24. At the same time, it transmits the force control program stored in the program memory 2-1.

As a result, the robot controllers 13 shift to the force control mode, and the two industrial robots 10 and 2 are included in the force control program to be executed.
The process of generating the second trajectory is replaced from the position control mode to the force control mode.

The force control module 1 includes a work fixing jig 2
The pressure on the work measured by the force sensor 12 mounted on the sensor board 0 is detected, the detection signal is taken in through the interface 6, converted to digital by the A / D board 14, and sent to the CPU board 2 through the I / O board 3. take in.

The CPU board 2 includes a force sensor 12
The process of generating the trajectories of the two industrial robots 10 and 22 using the detection signals of the above is replaced from the position control mode to the force control mode, and the coordinate conversion and gravity compensation are performed using the coordinate conversion matrix and physical parameters. A format in which the processing can be directly executed in each of the robot controllers 13 and 24,
For example performs arithmetic processing up section K _v * e _f error of the force of the above formula (2).

Two robot controllers 13 and 24
They are each force is force control program transmitted from the control module 1 receives the term K _v * e _f error of the force in the force control mode determined by the calculation of the force control module 1, for these force control The servomotors of the joints of the two manipulators 11 and 23 are servo-controlled in a force control mode based on a program and a control formula.

As described above, according to the fourth embodiment, the same effect as that of the first embodiment can be obtained, and a plurality of industrial robots 10 can be controlled by one force control module 1. , 22 can be driven and controlled by the force control mode.

In the fourth embodiment, the case where the robot controllers 13 and 24 are respectively connected to the interfaces 5-1 to 5-n of the force control module 1 has been described. As shown in (1), an external device 25, for example, a general processing device or a work monitoring device may be connected to the interfaces 5-1 to 5-n. (5) Next, a fifth embodiment of the present invention will be described.
The same parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 7 is a configuration diagram of a control system to which the force control module 1 is applied. In this control system, the communication means between the force control module 1 and the robot controller 13 is wireless communication using infrared rays or the like, and wireless force interfaces 26 and 27 are provided on the force control module 1 side and the robot controller 13 side, respectively. It has a connected configuration.

With such a configuration, when force control is required, a force control mode signal is transmitted from the force control module 1 to the robot controller 13 by wireless communication and stored in the program memory 2-1. The transmitted force control program is transmitted.

When the robot controller 13 receives the force control mode signal, the robot controller 13 shifts to the force control mode, and executes the process of generating the trajectory of the industrial robot 10 from the position control mode in the force control program to be executed. Replace with mode.

The force control module 1 includes a work fixing jig 2
A detection signal of the pressure on the work measured by the force sensor 12 mounted on the sensor 0 is received through wireless communication, and the detection signal is converted into a digital signal from the interface 6 by the A / D board 14 and transmitted through the I / O board 3. CPU
Take in board 2.

Then, the CPU board 2 includes the force sensor 12
The process of generating the trajectory of the industrial robot 10 using the detection signals of the above is replaced from the position control mode to the force control mode, and coordinate conversion and gravity compensation are performed using a coordinate conversion matrix and physical parameters. format that can be executed directly process, for example, performs arithmetic processing up section K _v * e _f error of the force in the above formula (2).

On the other hand, the robot controller 13 includes a force control program received by wireless communication from the force control module 1, and a term K _v * e of a force error term in the force control mode obtained by the arithmetic processing of the force control module 1. _f , and servo-controls the servomotors of the respective joints of the manipulator 11 in the force control mode based on the force control program and the control formula.

When data and the like are transmitted between the force control module 1 and the robot controller 13 by wireless communication as described above, the force control module 1 can be replaced with the force control mode without having to be connected to the robot controller 13.

[0079]

As described in detail above, claims 1 to 5 of the present invention.
According to (3), a control module capable of easily adding or removing a force control function can be provided. Further, according to the fourth and fifth aspects of the present invention, it is possible to provide a control system capable of easily adding or deleting a force control function by connecting and disconnecting to and from a position control controller.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a control module according to the present invention.

FIG. 2 is a configuration diagram of a control system to which the same force control module is applied.

FIG. 3 shows a second embodiment to which the control module according to the present invention is applied.
FIG. 1 is a configuration diagram illustrating a control system according to an embodiment.

FIG. 4 is a diagram illustrating a third example to which the control module according to the present invention is applied;
FIG. 1 is a configuration diagram illustrating a control system according to an embodiment.

FIG. 5 is a fourth diagram to which the control module according to the present invention is applied;
FIG. 1 is a configuration diagram illustrating a control system according to an embodiment.

FIG. 6 is a diagram showing an example of an external device connected to a control module.

FIG. 7 is a fifth diagram to which the control module according to the present invention is applied;
FIG. 1 is a configuration diagram illustrating a control system according to an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Force control module, 2 ... CPU board, 3 ... I / O board, 4 ... AD converter, 5-1-5-n, 6 ... Interface (I / F), 10 ... Industrial robot, 11 ... Multi joint , 12 ... force sensor, 13 ... robot controller.

Claims (5)

[Claims] When a control target is connected to and disconnected from a controller that controls a control object in a first control mode, and when the control target is connected to the controller, the first control mode is changed to the first control mode. A control module characterized by having a function of replacing with a different second control mode. 2. The control module according to claim 1, wherein the position control mode is replaced with a force control mode. 3. A process for taking in data measured by a force sensor attached to the control target and replacing a process of generating a trajectory of the control target using the data from a position control mode to a force control mode. The control module according to claim 1, wherein: 4. A control system for controlling the position of a controlled object by a controller for position control, wherein the force sensor attached to the controlled object is connectable to and detachable from the controller and connected to the controller. In this case, a control module that captures data measured by the force sensor and replaces the process of generating the trajectory of the controlled object using the data from the position control mode to the force control mode. Control system. 5. A process for generating a replaced trajectory, comprising:
The control system according to claim 4, wherein the controller has a function of saving the position control mode so that the controller can return to the position control mode.