JPH11134016A - Controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the whole controller small-sized by simplifying the device constitution when the controller is structured by making good use of a general computer. SOLUTION: The robot controller equipped with an inverter circuit 12 which controls motors 2 for the respective axes of a robot, a driving control part 14 which drives and controls the motor 2 through the inverter circuit 12, and a host control part 16 which outputs command values to the driving control part 14 uses a card type general computer (card PC) 40 as its host CPU which controls the host control part 16, and the driving control part 14 and host control part 16 are built on the same substrate (main board 24). Further, the host control part 16 is provided with a flash ROM 42 stored with a control program for the card PC 40. Consequently, the general computer which has wide expansibility is usable for the host control part 16 without making the device large in size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a controlled object having a plurality of actuators, such as a robot in which each axis is positioned and controlled by a plurality of motors.

[0002]

2. Description of the Related Art Conventionally, in this type of control device, the behavior of the entire control system including the control target is integrated while individually controlling a plurality of actuators provided in the control target. Need to be controlled
The drive system controls each actuator individually via a drive unit (drive circuit for energizing the actuator, etc.), and sets the control amount of each actuator based on the behavior of the control target and external commands. Therefore, it is considered that the drive control unit is divided into two systems, that is, a higher control unit that gives a control command corresponding to the control amount to the drive control unit. In order to separate the control system in this way, the CPU that controls the control operation in each control unit may be configured in a host / slave configuration.

In a control device such as an industrial robot control device, the operation (behavior) of an object to be controlled needs to be appropriately changed according to the type of a workpiece, machining conditions, and the like.
The user can change the control program of the host controller,
Because it is necessary to confirm
A function of a man-machine interface provided in a general-purpose computer is also required.

[0004] Recently, with the development of computer technology, general-purpose computers having advanced arithmetic capabilities have been provided at low cost as so-called personal computers. In order to provide a host CPU, using a commercially available general-purpose computer may be more advantageous in terms of development period or manufacturing cost than developing a dedicated host CPU.

However, since a general-purpose computer such as a personal computer has a single device configuration, a general-purpose computer must be configured as a control device that drives and controls a plurality of actuators as shown in FIG.
As shown in (a), on a motherboard of a general-purpose computer (a main board in which various interfaces for connecting a keyboard, a mouse, a display, a printer, etc. in addition to a CPU, a ROM, and a RAM) to function as a higher-level control unit are provided. It is necessary to connect a number of functional expansion boards (so-called expansion boards) in which slave CPUs and drive circuits for realizing the functions of the drive control section and the drive section are assembled. Separately, there is a problem that a device for function expansion as a control device must be manufactured and externally attached to a general-purpose computer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has an object to construct a control device using a general-purpose computer, thereby simplifying the device configuration and reducing the size of the entire control device. I do.

[0007]

According to a first aspect of the present invention, there is provided a control apparatus comprising: a driving unit;
A drive control unit having a slave CPU, and a host control unit having a host CPU;
U is a card-type general-purpose computer to which computer peripheral devices can be connected, and a higher-level control unit stores a program for causing the card-type general-purpose computer to execute arithmetic processing for actuator control. Is provided, and the host control unit including the memory and the card-type general-purpose computer and the drive control unit are:
Formed on the same substrate.

Therefore, according to the control device of the present invention, by using a card-type general-purpose computer (hereinafter, also referred to as a card PC) for the host CPU of the host control unit, the host control unit (specifically, the card PC) can use the computer. Although the function as a man-machine interface can be easily realized by connecting peripheral devices, the upper control unit and the drive control unit are formed on the same substrate, simplifying the device configuration and The size can be reduced.

Note that the computer peripheral devices connectable to the card PC are input / output devices generally commercially available as computer peripheral devices, such as a keyboard, a mouse, a display, and a printer. Various interfaces for connecting peripheral devices are incorporated. That is, the card PC has at least the same function as the motherboard of a general-purpose computer. And as such a card PC,
For example, IBM PC / AT (IBM Corporation, August 1984)
"CARD-PC" (trade name: SCE86437, manufactured by Epson) having the function of a personal computer announced in January
SCE86435) is known.

As described above, according to the present invention, since the card PC is used as the host CPU of the higher-level control unit, not only can the function as the man-machine interface of the card PC be utilized, but it will be incorporated in the card PC in the future. Even if the functions of the CPU and the interface are improved, by replacing the card PC incorporated in the board of the control device with the card PC having the improved function, the higher-level control unit has the arithmetic processing capability of the control amount and the higher-level control unit. The function as a man-machine interface can be enhanced very easily.

[0011] Further, since a memory in which a control program for operating the card PC for actuator control is stored in the upper control unit, the control program itself is rewritten by rewriting the control program written in the memory. By changing the function, the function as the control device can be enhanced.

Since the card PC is a general-purpose computer, the card PC is more susceptible to noise and the like than when a host CPU is developed exclusively for the control device, and the reliability of control may be reduced. Therefore, in order to prevent such a situation, as described in claim 2, the drive control unit includes a determination unit that determines whether the higher-level control unit is operating normally, and a determination unit that determines whether the higher-order control unit is operating normally. It is preferable to provide a driving stop unit that stops driving of the actuator by the driving unit when it is determined that the host control unit is operating abnormally.

In other words, even if the CPU incorporated in the card PC runs out of control and an abnormal command value is output from the higher-level control unit, the drive control unit will
Since the drive of the actuator can be stopped by determining that fact, the reliability of the control device can be ensured.

The determination of the abnormality of the higher-level control unit by the determination means is performed by periodically transmitting data for determining an abnormality from the card PC of the higher-level control unit to the drive control unit and determining whether the data is normal. However, for example, when the amount of change in the command value from the higher-level control unit is equal to or greater than a preset abnormality determination value, an abnormality in the higher-level control unit is determined. In this case, the abnormality determination can be performed without imposing a burden on the processing operation of the card PC.

The determination means and the drive stop means may be constituted by dedicated circuits. However, since the drive control section is provided with a slave CPU, the drive control section has the following features. The program executed by the slave CPU may realize the functions of the determination unit and the drive stop unit. In this way, a highly reliable control device can be realized without increasing the number of components of the drive control unit, and the control device can be simplified.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating a configuration of an entire robot control device according to an embodiment to which the present invention is applied.

The robot controller of this embodiment drives a plurality of AC servomotors (permanent magnet synchronous motors; hereinafter simply referred to as motors) 2 provided on each axis of an industrial robot to position each axis. And an inverter circuit 12 (only one inverter circuit 12 for one motor 2 is shown in the figure) as a drive unit for driving the motors 2 of the respective axes.
Control unit 14 that controls the motor 2 by controlling the motor (PWM control), and a higher-level control unit 16 that exchanges various data for motor control including the above-described command value with the drive control unit 14. Prepare. The inverter circuit 12
Is one board (power board) for each motor 2 of each axis
22, the drive control unit 14 and the host control unit 1
6 is mounted on the same board (main board) 24.

The robot controller is provided with an expansion board (communication board or the like for connecting to a network) 26 to which a function expansion circuit for expanding the function of the upper control unit 16 is attached, and the robot 2. An I / O board 28 to which an input / output circuit for taking in a signal from a sensor and outputting a control signal for driving another actuator, and a connector, and a power supply circuit for supplying power to the above-described units are included. An assembled power board 30 is also provided.

The extension board 26 and the I / O board 28 are directly connected to the main board 24 via connectors C1 and C2 for connecting their wiring patterns to the bus lines of the upper control unit 16, respectively. . In addition, the power supply board 30 is connected via a pair of connectors C3 and a power supply line.
While being connected to the main board 24, connectors C4 and
It is connected to the power board 22 via a power supply line and a connector C5 on the power board 22 side, and supplies power to the above-described units.

The inverter circuit 12 includes three switching elements Tr including power transistors and the like between a power supply line 12a and a power supply line 12b to which a DC high voltage (for example, 280 V) for driving a motor is supplied from a power supply board 30. It has a well-known configuration in which a feedback diode Df is connected in parallel with each switching element Tr, and its three output lines 12o (only one phase is shown in the figure) are connected via connectors C5, respectively. And U of motor 2
It is connected to V and W phase windings. The output line 12o is provided with a current sensor Si for detecting a current flowing through the motor 2, and a noise suppression coil (not shown) is also inserted.

The power board 22 has a connector C
6, connected to the main board 24 (specifically, the drive control unit 14) via the signal line and the connector C7 on the main board 24 side, and a drive signal (PWM signal) for each phase output from the drive control unit 14 is provided. While being input to the inverter circuit 12, the detection signal from the current sensor Si
Output to the 4 side. And on the power board 22 side,
The drive signal from the drive control unit 14 is amplified by the amplifier 12 c and input to the inverter circuit 12. In the main board 24, the host control unit 16 and the drive control unit 14
Are independently formed, and the ground line of the drive control unit 14 is set to have the same potential as the ground line of the inverter circuit 12.

The motor 2 is provided with an encoder 4 for detecting its position and speed, and a detection signal from the encoder 4 is also input to the drive control unit 14 via the connector C7. Next, the drive control unit 14 includes a slave CPU 32, a dual port RAM 34, a current control unit 36, an encoder interface (IF) 38 to which a detection signal from the encoder 4 is input, and a signal A to which a detection signal from the current sensor Si is input. A / D conversion unit 39 is provided.
The slave CPU 32 receives a command value indicating a control target of each motor 2 from the higher-level control unit 16, and receives a current command for each phase of the motor 2 based on the command value and detection signals from the encoder 4 and the current sensor Si. A value is obtained, and a drive signal corresponding to the current command value is output from the current control unit 36, thereby turning on and off each switching element Tr on the inverter circuit 12 side.
Is subjected to PWM control.

On the other hand, the higher-level control unit 16 is for performing trajectory generation of the robot and controlling man-machine relations other than motor control, and includes the aforementioned card PC 40 which is a general-purpose computer as a host CPU. A flash ROM (memory described in the claims) 42 storing a control program for operating the card PC 40, a backup RAM 44, and a dual port RAM 46. These components are connected to each other via a bus line, and the expansion board 26 and the I / O board 28 are also connected.

The dual port RAMs 34 and 46 provided in the drive control unit 14 and the high-order control unit 16 are for temporarily storing data transmitted and received between these units, such as command values for motor control. Not only data is read and written by the slave CPU 32 and the card PC 40, but also internal data is bidirectionally transmitted and received via the pair of photocouplers 48. This is to completely separate the power supply (ground line) between the upper control unit 16 and the drive control unit 14 in order to reduce noise. Therefore, the slave CPU 32 and the card PC 40 can exchange data without being affected by noise.

The drive control unit 14 performs motor control according to the command value written in the dual port RAM 34 as described above, and when there is an abnormality in the command value, rotation of the motor 2, and the like, the drive of the motor 2 is performed. Stop and give an alarm. That is, as shown in FIG. 2, when the drive control unit 14 (more specifically, the slave CPU 32) performs the motor control, first, in S110 (S represents a step), the upper control unit 16 written in the dual port RAM 34 is used. The command value from the side is read, and in S120, a change amount of the command value is obtained from a deviation between the read command value and the previously read command value, and the change amount is set to a predetermined threshold value (abnormality determination). Value), it is determined whether the command value is normal or not, and the processing as the determination means is executed.

If it is determined that the variation of the command value is smaller than the threshold value and the command value read this time is normal, the detection signals (sensor signals) from the current sensor Si and the encoder 4 are determined in S130. Read, followed by S140
Then, based on the read sensor signal, it is determined whether the motor current or the rotation state of the motor 2 is normal.
When it is determined in S140 that the motor 2 is operating normally, the process proceeds to S150, in which a current command value for the motor 2 is obtained, a drive signal is output from the current control unit 36, and motor control is performed. Execute.

On the other hand, in S120, it is determined that the command value from the higher-level control unit 16 is abnormal, or
At 0, when it is determined that the operation of the motor 2 is abnormal,
The process moves to S160. Then, in S160, the drive of the motor 2 is stopped by stopping the output of the drive signal from the current control unit 36 to the inverter circuit 12, and further,
A warning lamp or a buzzer (not shown) is driven to issue a warning to the user, and a process as a driving stop means is executed.

In the upper control unit 16, the card P
Since the C40 is provided with input / output ports for connecting a keyboard, a mouse, a display, a printer and the like, a wiring pattern for connecting these computer peripheral devices to the input / output ports is formed on the main board 24. The card PC 40 is connected to computer peripheral devices via this wiring pattern, and performs man-machine related control.

As described above, in the robot control device of the present embodiment, the card PC 40 is used as the host CPU that controls the upper control unit 16, and the upper control unit 16 and the drive control unit 14 use the same substrate ( That is, it is assembled on the main board 24) (see FIG. 3B). Therefore, when a general-purpose computer is used as the host CPU of the higher-level control unit 16, compared with the case where a general-purpose computer having a motherboard as shown in FIG. In addition, the device configuration can be simplified, and the control device can be downsized.

In this embodiment, when the slave CPU 32 of the drive control unit 14 controls the drive of the motor 2, the motor control process shown in FIG. An abnormality is determined, and if the command value is abnormal, the driving of the motor 2 is stopped. Accordingly, a general-purpose computer (card PC) is not used as a host CPU of the higher-level control unit 16 without using a CPU dedicated to the control device.
Although (40) is used, it is possible to prevent erroneous control caused by runaway of a computer or the like, and to secure reliability as a robot control device.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.
Various embodiments can be adopted. For example, in the above embodiment, the case where the present invention is applied to a robot control device that drives an AC servomotor by an inverter circuit has been described. However, other motors or an electromagnetic actuator using a solenoid can be electrically controlled. By applying the present invention to a device that controls a control target including a plurality of actuators, it is possible to obtain the same effects as those of the above embodiment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration of a robot control device according to an embodiment.

FIG. 2 is a flowchart illustrating a motor control process executed by a drive control unit.

FIG. 3 is an explanatory diagram showing a comparison between a case where a control system of a control device is assembled on a motherboard of a general-purpose computer and a case where a control system is configured using a card PC.

[Explanation of symbols]

2 ... motor, 4 ... encoder, 12 ... inverter circuit,
14: Drive control unit, 16: Host control unit, 22: Power board, 24: Main board, 40: Card PC, 42 ...
Flash memory.

Claims (4)

[Claims] A drive unit for driving each of a plurality of actuators provided in a control target; and a slave CPU for controlling each of the plurality of actuators via the drive unit according to a command value input from the outside. A higher-level control unit that includes a control unit and a host CPU, sets a control amount of each of the actuators for controlling the control target to a target state, and outputs a command value corresponding to the control amount to the drive control unit. And a host CPU of the higher-level control unit is configured by a card-type general-purpose computer to which a computer peripheral device can be connected. A memory for storing a program for executing arithmetic processing for control; and the memory and the card-type general-purpose computer. A control device, wherein the host control unit including a computer and the drive control unit are formed on the same substrate. 2. The drive control unit includes: a determination unit configured to determine whether the upper control unit is operating normally; and the determination unit determines that the upper control unit is operating abnormally. The control device according to claim 1, further comprising: a driving stop unit configured to stop driving of the actuator by the driving unit. 3. The method according to claim 2, wherein the determining unit determines an abnormal operation of the higher-level control unit when a change amount of a command value from the higher-level control unit is equal to or greater than a predetermined abnormality determination value. Item 3. The control device according to Item 2. 4. The control device according to claim 2, wherein said determination means and said drive stop means are realized by executing a program by said slave CPU.