JP2001322078A - Robot control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily realize hardware constitution corresponding to a desired application, at a low cost only by changing the program of an FPGA 26 according to a purpose. SOLUTION: This control device 10 is provided with a voltage driving circuit 38 for driving by applying driving voltage to a motor 32 for actuating the operating parts of a robot; a first programmable device 26 (such as an FPGA) for supplying the voltage driving circuit 38 with a control signal; and a sensor interface 36 for feeding a detection signal from the motor 32 back to the first programmable device 26. The control device 10 is further provided with a microcontroller 16 for reloading the program of the first FPGA 26; a communication interface 20 for incorporating external data into the controller 16 via a communication terminal 18; and a second FPGA 22 for executing an application program in cooperation with the first FPGA 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot controller, and more particularly to a robot controller which provides a hardware configuration according to a desired motion or application by using a programmable device capable of repeatedly changing a hardware logic circuit. About.

[0002]

2. Description of the Related Art For example, a desired operation (work, action, gesture,
For example, a controller of a personal robot that realizes a facial expression or the like requires a specific controller, a sensor interface, an actuator drive circuit, and the like corresponding to the intended operation.

Therefore, if the operation of the robot to be realized is greatly changed, a controller for controlling the operation becomes incompatible, and the intended operation cannot be realized unless almost all the components are changed.

[0004]

Therefore, in order to make the controller of the robot versatile, all control modes required for the actuator drive circuit, such as torque control, speed control, and position control, are to be supported.
This drive circuit becomes large-scale and is costly. In order to realize software servo in order to avoid such a hardware problem, if the number of actuators to be controlled is increased, the computing power of a higher-order processor is required, which increases the cost. Therefore, a high-speed arithmetic processor is required.

An object of the present invention is to provide a robot control apparatus which can easily configure hardware corresponding to a target motion or application at a low cost in order to solve the above-mentioned problems.

[0006]

According to the present invention, a motor provided in an operating portion of a robot, a driver for applying a drive voltage to the motor, and a hardware configuration for providing a control signal to the driver can be changed by a program. A control device for a robot including a first programmable controller.

[0007]

The driver of the motor that operates the operation part of the robot can easily set the voltage control and the current control by changing the program of the first programmable controller. As a result, the motor torque control and the motor control can be performed according to the purpose. Changes in speed control and the like become easy.

[0008]

According to the present invention, for example, a motor for driving an actuator of a robot is required for the actuator only by changing the hardware configuration of the programmable controller without using a large-scale circuit or a high-speed arithmetic processor. It can be controlled by the control method or mode performed.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the accompanying drawings.

[0010]

FIG. 1 is a circuit block diagram showing a hardware configuration of a control device 10 of a general-purpose personal robot according to an embodiment of the present invention.

In FIG. 1, the control device 10 includes a main control board 12 having a higher-level computing capability and a plurality of external connection boards 14, 14,...

The main control board 12 includes a microcontroller 16 including a microcomputer, a communication interface 20 for enabling connection with an external device such as a personal computer, a network or a personal communication terminal 18 such as a mobile phone, and a plurality of external connection boards 14. A programmable device 22 which is connected to a bus and whose internal logical operation circuit can be rewritten by a configuration from the microcontroller 16 and a memory 24 connected to the microcontroller 16 are mounted.

The programmable device 22 is, for example, an FPGA whose internal architecture has an SRAM structure.
(Field Programmable Gate Array) and other products are available from ALTERA and XILINX.

A memory 24 stores a nonvolatile memory section such as a flash memory for storing a program of the microcontroller 16 and data necessary for the configuration of the FPGA 22, and stores data used when the microcontroller 16 executes the program. R to do
And an AM unit.

Each external connection board 14 bus-connected to the main control board 12 has an FPGA 26 as a programmable device mounted thereon.
The internal logical operation circuit of A26 is configured according to the configuration data sent from the dedicated control signal bus.

A connection bus 30 interconnecting the FPGAs 22 and 26 mounted on the main control board 12 and the external connection boards 14 includes data, control signals and power supply lines.

The external connection board 14 has a displacement at the final stage via an encoder 34 connected to the motors 32, 32, 32, and a speed reducer, etc., which operate respective operation parts of a general-purpose personal robot (not shown). A general-purpose sensor interface 36 capable of capturing a digital pulse or an analog voltage signal, such as a potentiometer for measuring the force, a force sensor, or the like, is mounted. A control signal is captured by the FPGA 26 from the sensor interface 36.

Between each motor 32 and the FPGA 26, voltage driving circuits (drivers) 38, 3 for controlling a voltage applied to each motor 32 according to a command value from the FPGA 26.
8, 38 are connected respectively. This voltage drive circuit 38
Is a predetermined frequency (16 kHz) from the FPGA 26, for example.
Switching is repeated at about z) and the duty within one cycle (ON state where voltage is applied and OF where voltage is not applied)
PWM control for controlling the F state ratio) is used.

The external connection board 14 has a bus configuration shown by a dotted line and a solid line in FIG. 1 so that a plurality of boards having the same configuration can be connected according to the number of motors 32 used in the application. . In this case, the ID for identifying the board can be set by providing a jumper pin on the board or directly writing the configuration data of the FPGA 26.

The external connection board 14 can be connected not only to a board having the same configuration for driving the motor, but also to an image input / output board, a sound input / output board, and the like as required by the application.

Next, the configuration of the hardware shown in FIG. 1 will be described with reference to the operation flowchart shown in FIG.

First, the operation is started after the power is turned on or by a reset. In step S1, the microcontroller 16 determines whether or not the hardware configuration on the memory 24 mounted on the main control board 12 needs to be changed. . If a change is required in "YES", the update data is downloaded to the memory 24 from the communication terminal 18 via the microcontroller 16 via the various communication interfaces 20 in step S3. This data is downloaded to a non-volatile memory unit such as the above-mentioned flash memory, so that the configuration of the FPGA 22 can be performed without downloading if no hardware change is required at the next power-on (step S1). And “NO”).

Then, in step S3, when the download is completed or when the preparation for the configuration of the FPGA 22 is completed by the data previously stored in the nonvolatile memory unit, the main control board 12
Configuration is performed using the dedicated control signal bus 28 in order from the upper FPGA 22.

When the configuration is completed in step S5 and the hardware configuration is determined, in step S7 initialization of the software part depending on the hardware is performed in the same manner as in a normal microcomputer device, and then in step S9, the initialization is performed according to the hardware. Execute the application software program.

The configuration data for the FPGA need not always be one, and a plurality of configuration data can be stored in the non-volatile memory unit. Can also be used.

The hardware can be changed even when the application software program is executed. For example, if there is a request for change on the application in step S11, the flow returns to step S3 to download another data, Configure with different data from above.

An operation flowchart for configuring hardware in the FPGA 26 mounted on the external connection board 14 is the same as that in FIG. 2 and the description thereof is omitted.

Next, different embodiments of the specific hardware configuration will be described with reference to FIGS. This embodiment relates to a control mode of the motor. This motor is used, for example, to operate a plurality of operating parts of a general-purpose personal robot. 1) The application using the motor 32 is the motor 3
In the case of torque control using the torque output from the motor 2: In this case, the output torque of the motor 32 can be simply calculated as a value proportional to the motor current using the torque constant of the motor 32. At this time, the hardware of each motor shaft can be configured on the external connection board 14 as shown in FIG.

That is, the motor 3
2 normally outputs a voltage value proportional to the current value.
By sampling as a digital discrete value by the D converter 42, it can be input to the configured logic operation circuit of the FPGA 26.

The current sensor 40 and the AD converter 42
It is mounted on the external connection board 14 in advance as a general-purpose sensor interface 36 necessary for motor control.

The FPGA 26 has a reference value register 44 for setting a required torque (a current value calculated based on a torque constant) at each time calculated by a host controller mounted on the main control board 12. Reference value provided from register 44 and AD converter 42
From a current value output from the arithmetic circuit 46 and a proportional gain unit 48 for multiplying a calculation result from the arithmetic circuit 46 by a preset proportional gain. The value multiplied by the output proportional gain is input to the voltage drive circuit 38 of the motor 32 as a voltage command value.

The voltage command value outputs a PWM signal as described above. These series of calculations are executed for each control cycle. Assuming that the control cycle can be executed at, for example, about 10 kHz, the proportional gain to be multiplied by the proportional gain unit 48 is set to be sufficiently large to control the current (torque).

In this application,
The FPGA 26 on the external connection board 14 may be configured as a logical operation circuit having the configuration shown in FIG. 2) When the control of the motor 32 required for the application is speed control: In this case as well, the motor 3
In order to improve the controllability of the circuit 2, the circuit configuration enclosed by the dashed line in FIG. 3 is used as it is for the current drive circuit 50. The configuration of the FPGA 26 is further changed as shown in FIG. Is added.

The sensor interface 36 of the external connection board 14 is provided with a port capable of connecting an encoder signal. In this application, an encoder counter 52 capable of counting a rotation angle from the signal into a pulse count value is configured in the FPGA 26. .

The rotational angle of the motor 32 at the time when the differentiator 54 differentiates the time with respect to time is defined as the rotational speed. Specifically, the rotation speed can be calculated from the count value changed during the speed control cycle and the known resolution and control cycle of the encoder 34. And the FPGA 26
The reference value register 56 stores the rotation speed required for the motor 32 at each time calculated by the upper controller mounted on the main control board 12, the reference value from this register 56 and the current value obtained from the differentiator 54. And a PI (proportional-integral) controller 6 which receives the error output value as an input and outputs the operation result as a reference current value to the current drive circuit 50.
0 is further included.

This reference current value is set in the reference value register 44 of the current drive circuit 50 surrounded by the dotted line shown in FIG.

The above-described series of calculations and updating of the current reference value based on the calculation results are executed for each control cycle. The control cycle is, for example, about 4 kHz, and stable speed control is possible.

When the operation by the main control board 12 as the upper controller is relatively simple,
In order to distribute the load of the logic operation circuit in the FPGA 26, the FPGA 26 on the external connection board 14 is kept in the configuration of FIG.
The current drive circuit 50 and the encoder counter 52 shown in FIG.
May be configured. 3) The application shown in FIG. 5 is for controlling the position of the motor 32 (rotation angle control of the motor), and will be described below.

In this case, the FPG on the external connection board 14
The configuration in A26 is the same as that in FIG. Host controller, that is, FPGA of main control board 12
22 is an encoder counter 5 on the external connection board 14
The counter value measured in step 2 is updated via the connection bus 30 to obtain the rotation angle of the motor 32.

The PFGA 22 has a rotation angle reference value register 62 for storing a rotation angle reference value calculated by the microcontroller 16 of the main control board 12 by an application program.
And a proportional operation controller 66 for multiplying an error value output from the operation circuit 64 by a proportional gain, Each speed reference value of each motor 32 is calculated.

The above calculation and updating of each speed reference value are performed for each position control cycle. The position control cycle is, for example, 50
It may be set to about 0 Hz. 4) The application shown in FIG. 6 shows the configuration of the position control of the motor 32 as in FIG. 5, but the position detector is provided on the final output shaft decelerated from the motor rotation shaft via the speed reducer 68. The potentiometer 70 is used.

As the output of the potentiometer 70, a voltage value corresponding to the rotation angle of the final stage is obtained and input to the AD converter 42 of the sensor interface 36. This conversion value is
It is input to the FPGA 26 as a digital value. Note that F
The logic operation circuit of the PGA 26 has the same configuration as the speed control of the motor 32 shown in FIG.

Here, the external connection board 14 can be equipped with a plurality of axes of the above configuration on one card, and a combination thereof can be selected.

The FPGA 22 on the host controller (main control board) 12 executes a series of fixed arithmetic operations which are repeated every control cycle according to the application in order to execute the program in the microcontroller 16 at high speed. It is also a device for hardware. In addition, for a plurality of external connection boards 14 connected via the external connection bus 30, the update of the sensor value and the update of the reference value are performed at regular intervals independently of the microcontroller 16.

As described above, according to the present invention, as the hardware, for example, the general-purpose configuration shown in FIG. 1 is used, and according to the motor control mode required for the application, that is, the torque control and the speed control, etc. By changing the program of the FPGA, a hardware configuration specialized for a target application can be easily realized.

The present invention is not limited to the above-described embodiment, and various modifications can be made without changing the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram illustrating a hardware configuration of a control device for a personal robot according to an embodiment of the present invention.

FIG. 2 is an operation flowchart for performing configuration of the hardware shown in FIG. 1;

FIG. 3 is a circuit block diagram for performing torque control of a motor that operates an operation part of the personal robot.

FIG. 4 is a circuit block diagram for controlling the speed of a motor that operates an operation part of the personal robot.

FIG. 5 is a circuit block diagram for performing position control (rotation angle control) of a motor that operates an operation part of the personal robot.

FIG. 6 is a circuit block diagram showing another embodiment for performing position control of the motor corresponding to FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Robot control device 12 ... Main control board 14 ... External connection board 16 ... Microcontroller 18 ... Communication terminal 20 ... Communication interface 22, 26 ... Programmable device (FPGA) 24 ... Memory 28, 30 ... Connection bus 32 ... Motor 36 … Sensor interface 38… Voltage drive circuit (driver)

Claims (5)

[Claims] 1. A motor provided in an operation part of a robot, a driver for applying a drive voltage to the motor, and a first programmable controller capable of changing a hardware configuration for providing a control signal to the driver by a program. Robot control device. 2. The control device for a robot according to claim 1, further comprising rewriting means for rewriting a program of said first programmable controller based on configuration data. 3. The control device for a robot according to claim 2, wherein said rewriting means is connected to means for taking in external data. 4. The robot controller according to claim 2, further comprising a second programmable controller that executes the application program rewritten by the rewriting means in cooperation with the first programmable controller. 5. The sensor according to claim 1, wherein said first programmable controller further comprises a sensor interface means for adjusting the control signal by feeding back a detection signal based on torque, speed or position of said operating part driven by said motor. 5. The control device for a robot according to any one of items 4 to 4.