JPH04160409A - Numerical controller for robot - Google Patents

Abstract

PURPOSE:To provide the maintenance of data to be saved even if a communication system becomes abnormal by transferring the parameters of a system from a volatile memory to a stand-by memory according to a saving instruction. CONSTITUTION:When the parameters regarding the robot system need not be saved, the parameter values are stored temporarily in the volatile memory 6 and when there is the instruction for saving the parameters from outside, the data in the memory 6 are transferred to the stand-by memory 5 through a write control circuit 14. Then a control circuit 14 is provided between a CPU 2 and a communication control circuit 9, and the memory 5 and its contents are not rewritten unless a specific procedure is performed when the parameter values of the system are written in the memory 5; and the parameter values which are characteristic to the robot 7 reside on the memory 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The numerical control device for a robot according to the present invention will be explained in detail according to the following items.

A. Industrial field of application B1 Overview of the invention C1 Prior art [Figure 5] a. General background Conventional example [Figure 5] D8 Problem to be solved by the invention [Figure 5] E1 Solving the problem Means F, Example [Figs. 1 to 4] a. Configuration [Fig. 1] b. Write control circuit [Figs. 2 and 3] c. Measures against accidents regarding LAN [Fig. 4] ] G1 Effects of the Invention (A, Industrial Application Field) The present invention relates to a new robot numerical control device. Specifically, the present invention aims to provide a new robot numerical control device that guarantees the preservation of operating programs and parameter values related to the robot system even when the CPU runs out of control or when the communication system malfunctions.

(B. Summary of the Invention) The numerical control device for the robot of the present invention includes a CPU (central processing unit) that interprets and executes the robot's operation program, a volatile memory connected to the CPU, and external equipment. A communication connection circuit provided for communication, an electrically erasable nonvolatile save memory provided for storing robot operation programs and/or parameter values related to the robot system, and a CPU bus. and the save memory, and outputs a command according to a predetermined write procedure to the save memory when data is written to the save memory from the CPU or communication connection circuit. When there is no need to save parameters related to the robot system, parameter values are temporarily stored in volatile memory, and data in the volatile memory is controlled to be written when an external command is given to save parameters. It is designed to be transferred to the save memory via a circuit, and by using nonvolatile memory to save the robot system parameters, it is possible to preserve the data when the power is cut off, and also to save it when εjU goes out of control. It is designed to prevent the contents of the memory for the device from being easily rewritten, and is also equipped with a communication status monitoring circuit that monitors the quality of the communication status with external equipment, and the communication status monitoring circuit detects an abnormality in the communication status. By transferring the contents of the volatile memory to the save memory, it is a complete measure to ensure that the data to be saved can be preserved even in the event of an abnormality in the communication system.

(C, Prior Art) [Figure 5] (a, General Background) In recent years, robots have been increasingly used as working units in production lines.

In such a case, each robot is connected to a network within the premises (so-called rLocalArea Network, hereinafter referred to as rLANJ for short), and mutual synchronization adjustment and information transmission regarding programs, work types, etc. are carried out through the LAN. is realized. In a production line built with LAN as the backbone, a host computer (hereinafter simply referred to as "host") is installed, and the status of all robots can be managed by this host. It has become.

In other words, the host can store parameters that are used only inside the robot, such as constants for software servo circuits, parameters for generating acceleration/deceleration patterns, and constants for returning to the origin. This allows the host to manage the status of all robots.

However, if the host manages all of the robot's parameters, it is assumed that the host and LAN are in operation when the robot is operated.

In other words, when making individual adjustments to robots or when the production line is stopped, if you want to operate a certain robot, you have to start up the LAN including the host each time, so you can avoid the hassle of making adjustments. do not have.

Furthermore, the constants of the servo circuit are parameters unique to each robot, and once the workpiece to be machined has been determined, there is no need to change them frequently thereafter.

Therefore, it is desirable that the parameters specific to each robot be always visible to the host (that is, readable at all times) while the LAN is operating, and that the robot itself also have these parameters. .

(b. Conventional example) [Fig. 5] Therefore, the one shown in Fig. 5 is known as m numerical control devices a that are capable of registering parameters unique to a robot.

In the figure, s is a bus, and CPLI (
central processing unit) C is a memory, that is, ROM (Re
ad 0nly Memory) d, E E P
ROM (Electrically Erasable)
and Programmable ROM)
e, RAM (Random 8cc
In addition to accessing the ess Memory) f, it also exchanges information with a servo control section provided for controlling the motion of the robot g.

The ROMd is provided to describe the operation of the CPUc, and stores therein a procedure for interpreting the robot language, a procedure for transferring necessary information to the servo control section, and the like.

RAMf is usually the work area of the CPUc.
However, it is also a part where the operation program, servo parameters, etc. of the robot g are temporarily saved.

EEPROMe can be electrically erased, and
It is a nonvolatile memory, and its contents are not erased even when the power is cut off. Therefore,
Of the servo parameters and robot programs, information that is frequently used and does not require modification for a relatively long time, and information that needs to be saved when the power is cut off, is stored in the EEFROMe.

Therefore, EEP connected to CPU c through bus b
It is desirable to have the necessary parameters inside the ROMe so that the data can be retained even after the power is cut off, and the robot can be operated on the vehicle body even when the LAN is not connected. It is believed that there is. For example, please refer to JP-A-63-285607 and JP-A-63-285608.

(D. Problems to be Solved by the Invention) [Figure 5] By the way, data can be saved when the power is cut off by providing a nonvolatile memory as described above, but other abnormal conditions, such as CPU runaway and L
There is a problem in that data preservation is not necessarily guaranteed in the event of an AN accident or the like.

In other words, in a configuration in which CPLlc and EEPROMe are directly connected via bus b, the EEF
Since the sequence for accessing ROMe may be preceded, there is a risk that data may be erroneously rewritten.

In addition, when the LAN operation stops due to some kind of failure, or when the connection between the robot and the LAN is severed due to the operator's carelessness, the operation to maintain the parameters is not performed consciously. Because there is no
There is a risk that necessary parameters may be erased without being transferred to the EEFROM.

Also, during teaching operations using a teaching pendant, etc.
There is an inconvenience that data cannot be guaranteed in the event that the teaching pendant becomes detached from the main body of the numerical control device.

Furthermore, in the numerical control device configured as described above, dual management of information in the EEFROM and information in the RAM is required, which causes a new problem of complicated management. For this purpose, for example, as disclosed in Japanese Patent Laid-Open No. 63-285608, a user terminal i is provided, and this is connected to a bus b via a user interface j (see FIG. 5).
When there is information that is not registered in the EEFROM, the operator is prompted to confirm whether or not to transfer this information to the EEFROM, and the operator, based on the display, instructs the device whether or not to register the information. Examples of methods include:

However, if this method is used, the robot numerical control device will
In the case of connecting to N, the amount of information in the packet increases to display unregistered information one after another, increasing the load on the LAN, and an emergency situation such as an emergency stop occurs. Next, there is a risk that the flow of packet communication will be obstructed.

(E. Means for Solving the Problems) Therefore, in order to solve the above-mentioned problems, the numerical control device for the robot of the present invention first sets out the robot operation program in order to maintain the parameters of the robot system when the CPU runs out of control. CPU that interprets and executes (
A central processing unit), a volatile memory connected to the CPU, a communication connection circuit provided for communicating with external equipment, and storage of robot operation programs and/or parameter values related to the robot system. an electrically erasable nonvolatile save memory provided for the purpose of the transfer, and an electrically erasable nonvolatile save memory provided between the CPU bus and the save memory, and in which data is not written to the save memory from the CPU or the communication connection circuit. and a write control circuit that outputs a command according to a predetermined writing procedure to the save memory when saving the parameters related to the robot system, and when the parameters related to the robot system do not need to be saved, the parameter values are temporarily stored in the volatile memory. The data in the volatile memory is transferred to the save memory via the write control circuit when a parameter save command is issued from the outside.

Therefore, according to this, a write control circuit is provided between the CPU or communication connection circuit and the save memory, and unless a prescribed procedure is followed when writing parameter values for the robot system to the save memory, The contents are not easily rewritten, and even if the CPU goes out of control, the probability that the predetermined write procedure will be executed accidentally is very low. Since parameter values unique to the robot will reside in the evacuation memory by the evacuation operation, there is no particular need for dual management of data, and information not registered in the evacuation memory will be displayed. etc. are unnecessary, so there is no burden on communication processing.

Regarding network accident countermeasures, in addition to the above-mentioned components, we also provide a communication status monitoring circuit that monitors the quality of the communication status with external devices, and when the communication status monitoring circuit detects an abnormality in the communication status. Second, the contents of the volatile memory are transferred to the save memory.

Therefore, according to this, even if an abnormality occurs in the communication state due to an accident in the communication line (including communication via the teaching device), it is possible to maintain the robot operation program and the parameters of the robot system.

(F. Implementation/Example) [Figures 1 to 4] The details of the numerical control device for the robot of the present invention will be described below according to the illustrated embodiment.

(a, configuration) [Figure 1] Figure 1 shows a robot numerical control device 1 connected to a LAN.
It shows.

Regarding the numerical control device 1, the CPU 2 connects to R via the bus 3.
It accesses the OM4, EEPROM5, and RAM6, and also exchanges information with the servo control unit 8 regarding the robot 7.

The numerical control device 1 is connected to the LAN via the LAN interface 9, and instructions from the outside can be received via the main line 10 of the constituent network. This configuration allows the host 11 connected to the trunk line 10 to directly access the servo control unit 8.

A user terminal 12 is connected to the bus 3 via a user interface 13.

In such a configuration, the host 11 often controls the robot 7 through the LAN, so the operator must take the trouble to send the evacuation command to the EEFROM 5 to save data such as servo parameters to the robot 7 via the user terminal 12. It is easier for the host 11 to do this than to instruct the host 11 to do so, and it is considered appropriate that the host 11 should rather decide on the timing of this evacuation.

(b. Write Control Circuit) [FIGS. 2 and 3] Incidentally, in this embodiment, the EEPROM 5 is not directly connected to the bus 3, but is connected to the bus 3 via the write control circuit 14.

This is due to the following reasons.

In other words, regarding writing data to the EEPROM 5, if the EEPROM 5 is used as a save memory, if the data is easily written to it, there is a risk that the data stored in the EEPROM will be destroyed when the CPU 2 goes out of control. This is because it invites trouble. In particular, DMA (Direct Memory Acc) allows direct access to memory from a LAN.
If the ess) circuit is used within the LAN interface 9, the risk is even higher.

Therefore, in order to protect the stored information in the EEPROMS, a write control circuit 14 is provided to limit the writing of data to the EEPROM 5, and data is written to the EEFROM 5 via this circuit. This prevents such data from being destroyed.

That is, the write control circuit 14 is configured such that the data in the EEPROMS can only be rewritten when the CPU 2 or the DMA circuit sends an intentional write command according to a predetermined procedure. It is not possible to write data to the EEFROM 5 using a write pulse, and for this purpose the CPU 2
A DMA circuit must generate a predetermined signal for writing.

For example, the easiest method is to use a parallel interface (abbreviated as rP I OJ) 15.15' as the write control circuit 14 as shown in FIG.
is to use.

In the figure, 15 is the write control terminal of EEPROM 5 (rF
), HA extension control input terminal (Tllr), PIO interposed between the address input terminal (ADDRESS) and bus 3, and 15' is the data input/output terminal (DATA) of EEPROM 5 and bus 3. This is the PIO interposed between.

In this way, bus 3 and EEPROM 5 are not directly connected, Plot 5.15' is provided between them, and writing to EEPROM 5 and reading pulses are sent through PjO15, 15'. . In other words,
EEPR can only be activated by a signal according to a predetermined writing procedure.
CPI because it is not easy to write data in OMS
It is very unlikely that such a write procedure will be executed by chance when J2 goes out of control. Therefore, EEPROM
The possibility of accidental access to the EEFROM 5 is low in situations other than when a write command to the EEFROM 5 is created by the program of the CPU 2, and it is possible to obtain considerable reliability regarding the preservation of internal data.

Incidentally, an unnecessary write operation may occur in the EEFROM 5 due to a pulse generated when the power is turned on or off, or an accidental pulse generated due to the initial setting of Plot 5.15'.

In order to prevent this, an example of a write control circuit 14A that does not generate a write pulse unless a certain sequence is obtained from the CPU 2 or DMA circuit is shown in FIG.
).

Signals are exchanged between the bus 3 and the EEPROM 5 via three PIOs 161, 162, and 163. Address data regarding EEFROM5 is PI016. The settings are made via the PIO 162, and data input/output is performed via the PIO 162.

The PIO 163 is related to write and read control for the EEPRoM5, and among its output signals (these are expressed as Ss, sb, sCs, and sd), S is the D input terminal of the D-type flip-flop 17 and the subsequent AND gate. 18 input terminals, and the signal S
b is sent to the clock input terminal of the D-type flip-flop 17 and the clock input terminal of the shift register 19.

The signal S and the output of the D-type flip-flop 17 are input to the AND gate 18, and the output of the AND gate 18 (denoted as ' S +aJ) is sent to the shift register 19.

The output S18 of the AND gate 18 and the output signal of the shift register 19 (this is written as 'S+9J) are sent to the AND gate 20, and the output signal of the AND gate 20 (this is written as 'rS2°') is written. E as a control signal
It is sent to the write control input terminal (WRITE) of the EPROM 5.

Further, the signal Se is used as a signal for setting the D-type clip-flop 17 and resetting the shift register 19, and the signal Sd is used as a read control signal for the EEFROM 5.
The data is sent to the read control input terminal (READ) of the .

Therefore, in the generation of the write control signal by the circuit 14A, as is clear from the time chart of FIG. According to the timing of Sb, the first shift signal "S
19°' to 'S + eJ.

After a predetermined number of stages have been shifted, the rising pulse of the signal SI6 is input to the AND gate 20 while the pulse of the signal s+9 is being output (that is, the signal S
This means that 1 is output at a predetermined timing. ), a write control pulse is obtained, and such a pulse is not obtained at other times.

With the above circuit, it is impossible to write data to the EEFROM 5 unless a signal according to a series of sequences is sent from the CPU 2 or the DMA circuit to the PIO 163. Therefore, unless there is a logical error in the program, it is impossible to write data to the EEFROM 5. Data in the EEPROMS is not rewritten when the CPU 2 goes out of control, and existing data is protected.

It goes without saying that simply using the signal S+8 as a write control signal without providing the shift register 19 in the circuit described above has the effect of preventing unnecessary writing to the EEFROM 5 due to accidental pulses.

(c. Accident countermeasures for LAN) [Figure 4] For production lines, accidents in the internal network should be assumed. Otherwise, data indicating the internal state of the robot may be lost due to a LAN accident.

FIG. 4 shows an example of measures taken against such LAN accidents.

In addition to the components explained in Fig. 1, the configuration includes LA
An N state detection section 21 is added.

That is, the LAN interface 9 is connected to the trunk line 10 and finds and processes packets related to the robot 7, but if an accident occurs with the LAN, the carrier may stop (or the packet flow may be poor). The LAN state detection unit 21 constantly monitors such changes, as these are observed as phenomena in which the impedance of the signal line changes more than necessary. In addition, if information about whether the LAN is working normally can be included in the packet,
Of course, such information may be used.

If the LAN state detection unit 21 detects the occurrence of an accident, it treats this as an emergency situation and notifies the CPU 2 of the occurrence by applying an interlabdo (rlNTRJ).

When the CPU 2 receives this I NTR command, if no other priority task is being executed, the CPU 2 updates the parameters etc. in the servo control section 8 and the robot program in the RAM 6 according to the procedure written in advance in the ROMJ. The data on parameters, etc. are transferred to the EEFROM 5 and saved therein.

As a result, even if it becomes impossible to control each robot due to a LAN accident, data regarding the internal state of the robot at that time is guaranteed.

Note that the same concept as that of the LAN state detection section 21 can also be applied to a state detection circuit for monitoring the connection state between the teaching pendant and the numerical control device.

(G. Effects of the Invention) As is clear from the above description, the first aspect of the present invention is a CPU (Central Processing Unit) that interprets and executes the robot's operation program, and a CPU that is connected to the CPU. an electrically erasable volatile memory provided for storing robot operation programs and/or parameter values related to the robot system; and a communication connection circuit provided for communicating with external equipment. It is provided between a non-volatile save memory, a CPU bus, and the save memory, and is configured to follow a predetermined writing procedure when writing data to the save memory from the CPU or communication connection circuit. It is equipped with a write control circuit that outputs commands to the save memory, and when it is not necessary to save parameters related to the robot system, the parameter values are temporarily stored in the volatile memory, and when a parameter save command is issued from outside. It is characterized in that data in the volatile memory is sometimes transferred to the save memory via the write control circuit.

Therefore, according to this, a write control circuit is provided between the CPU or communication connection circuit and the save memory,
When writing parameter values for a robot system to the save memory, the contents cannot be easily rewritten unless a prescribed procedure is followed.
Since the probability that a predetermined write procedure will be executed accidentally when U goes out of control is extremely low, the possibility that the contents of the save memory will be easily rewritten is low. Since parameter values unique to the robot will reside in the evacuation memory by the evacuation operation, there is no particular need for dual management of data, and information not registered in the evacuation memory will be displayed. etc. are unnecessary, so there is no burden on communication processing.

In addition to the above-mentioned components, the second aspect of the present invention is to provide a communication status monitoring circuit for monitoring the quality of the communication status with external equipment, and the communication status monitoring circuit detects abnormalities in the communication status. It is characterized in that the contents of the volatile memory are transferred to the save memory upon detection.

Therefore, according to this, even if an abnormality occurs in the communication state due to an accident in the communication line (including communication via the teaching device), it is possible to maintain the robot operation program and the parameters of the robot system.

Furthermore, the configuration of the write control circuit includes a control output circuit accessed by the CPU or a communication connection circuit, a delay circuit provided at a subsequent stage of the control output circuit, and an output of the control output circuit and an output of the delay circuit. It has an AND circuit that outputs an AND, and by sending the output signal of the AND circuit to the save memory as a write command, the control output circuit and the output of the delay circuit will not be in the same state at a predetermined timing. By imposing a procedure in which a write command is not generated for as long as possible, it is possible to reduce the risk that the contents of the save memory will be rewritten due to the accidental generation of a pulse.

It should be noted that the above-mentioned embodiment is only one embodiment of the numerical control device for the robot of the present invention, and the technical scope of the present invention should not be narrowly interpreted based on this alone. For example, although EEFROM is shown as a save memory in the above embodiment, it is not limited to EEPROM devices that utilize the avalanche effect, but also non-volatile devices in a broad sense that are equivalent to EEPROM in their functions, such as RAM supported by a battery backup circuit. It goes without saying that a memory can be used, and all embodiments that do not depart from the spirit of the present invention are included within the technical scope of the present invention.

[Brief explanation of the drawing]

1 to 4 show an example of the implementation of the numerical control device for the robot of the present invention. FIG. 1 is a block diagram showing the numerical control device and the robot connected to a network, and FIG. A block diagram showing an example of a write control circuit, FIG. 3 shows another example of a write control circuit, (
A) is a circuit block diagram, (B) is a schematic time chart diagram, Figure 4 is a block diagram for explaining network accident countermeasures, and Figure 5 is a block diagram showing an example of a conventional robot numerical control device. It is a diagram. Explanation of symbols 1... Robot numerical control device, 2... CPU, 3... Bus, 5... Save memory, 6... Volatile memory, 7... Robot, 9...
・Communication connection circuit, 14...Write control circuit, 15.15'...Write control circuit, 14A...Write control circuit, 163...Control output circuit, 17...Delay circuit , 18... AND circuit, 16!1, 17.18... Control output circuit, 19...
Delay circuit, 20...AND circuit, 21...Communication status monitoring circuit Applicant: Sony Corporation

Claims (3)

[Claims] (1) C that interprets and executes the robot's operation program
A PU (Central Processing Unit), a volatile memory connected to the CPU, a communication connection circuit provided for communicating with external equipment, and a robot operation program and/or a robot system-related parameter value. An electrically erasable non-volatile save memory provided for storage, provided between the CPU bus and the save memory, and
A write control circuit that outputs a command according to a predetermined writing procedure to the save memory when data is written to the save memory from the CPU or communication connection circuit, and when saving parameters related to the robot system is not required. Parameter values are temporarily stored in volatile memory, and when there is an external parameter save command, the data in the volatile memory is transferred to the save memory via the write control circuit. A robot numerical control device featuring (2) A communication status monitoring circuit is provided to monitor the quality of the communication status with external equipment, and when the communication status monitoring circuit detects an abnormality in the communication status, the contents of the volatile memory are transferred to the save memory. The numerical control device for a robot according to claim 1, characterized in that: (3) The write control circuit is a logical product of a control output circuit accessed by the CPU or a communication connection circuit, a delay circuit provided after the control output circuit, and the output of the control output circuit and the output of the delay circuit. 3. The numerical control device for a robot according to claim 1 or 2, comprising an AND circuit that outputs the AND circuit, and an output signal of the AND circuit is sent to the save memory as a write command.