JP3003197B2 - Robot numerical controller - Google Patents

Description

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

A. Industrial applications B. Summary of the invention C. Prior art [Fig. 5] a. General background b. Conventional example [Fig. 5] D. Problems to be solved by the invention [Fig. 5] E Means for Solving the Problems F. Embodiment [FIGS. 1 to 4] a. Basic Configuration [FIG. 1] b. Write Control Circuit [FIGS. 2 and 3] c. Anti-accident measures [Fig. 4] G. Effects of the invention (A. Industrial application field) The present invention relates to a novel numerical controller for a robot. More specifically, an object of the present invention is to provide a novel robot numerical controller that guarantees the preservation of operation programs and parameter values for a robot system when a communication system is abnormal.

(B. Summary of the Invention) The numerical control device of the robot of the present invention is a CPU (Central Processing Unit) that interprets and executes the operation program of the robot.
A volatile memory connected to the CPU, a communication connection circuit provided for performing communication with an external device, a communication state monitoring circuit for monitoring a communication state of the communication connection circuit, and a robot operation program. And / or an electrically erasable non-volatile evacuation memory provided for storing parameter values related to the robot system and a CPU or communication connection provided between the CPU bus and the evacuation memory. A write control circuit that outputs a command in accordance with a predetermined write procedure to the evacuation memory when data in the evacuation memory is written from the circuit, and when the communication status monitoring circuit detects an abnormality in the communication status, The contents of the volatile memory are transferred to the evacuation memory via the write control circuit, thereby preserving the data to be saved even when the communication system becomes abnormal. It was subjected to safety measures so as to be able to achieve.

(C. Prior Art) [FIG. 5] (a. General Background) Regarding the usage of robots in recent years, robots are increasingly operating as work units in one production line.

In such a case, each robot is connected to a premises network (a so-called “Local Area Network”, hereinafter abbreviated as “LAN”).
Call. ) To realize mutual synchronization adjustment and information transmission about programs, types of work, etc., via LAN. In a production line constructed on the basis of a LAN, one host computer (hereinafter simply referred to as "host") is provided, and the state of all robots can be managed by this host. .

That is, parameters used only inside the robot,
For example, the host can hold the constants of the software servo circuit, the parameters for generating the acceleration / deceleration pattern, and the constants at the time of origin return, so that the host can manage the state of all robots. Becomes

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

In other words, when making individual adjustments to the robot or when the production line is stopped, if you want to operate a certain robot, you must start up the LAN including the host each time. Absent.

In particular, the constant of the servo circuit is a parameter unique to each robot, and once the work to be processed is determined, it is not necessary to change it frequently thereafter.

Therefore, it is desirable that the parameters unique to each robot are always visible from the host during the operation of the LAN (that is, always readable), and that the robot itself has these parameters.

(B. Conventional example) [FIG. 5] As an example a of a numerical control device capable of registering parameters unique to a robot, the one shown in FIG. 5 is known.

In the figure, b is a bus, and a CPU (Central Processing Unit) c is a memory, that is, a ROM (Read Only Memory) through the bus b.
ory) d, EEPROM (Electrically Erasable and Program
In addition to accessing a mable ROM e and a random access memory (RAM) f, information is exchanged with a servo control unit h provided for controlling the operation of the robot g.

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

The RAMf normally works as a work area (work area) of the CPUc, but is also a part where the operation program and servo parameters of the robot g are temporarily saved.

The EEPROMe is an electrically erasable and non-volatile memory, and has the property that its contents are not erased even if the power is turned off. Therefore, information that is frequently used among the servo parameters and the robot program and does not need to be changed for a relatively long time or information that needs to be saved when the power is turned off is stored in the EEPROM.

Then, EEPROMe connected to CPUc through bus b
Having the necessary parameters inside the device is desirable in that the data can be retained even after the power is turned off, and that the robot can operate alone even when the LAN is not operating. Conceivable. For example, see JP-A-63-285607 and JP-A-63-285608.

(D. Problems to be Solved by the Invention) [FIG. 5] By the way, data can be saved when the power is turned off by providing the above-mentioned nonvolatile memory. When a LAN accident occurs, there is a problem that data preservation is not always guaranteed.

In other words, when the operation of the LAN is stopped due to some kind of failure, or when the connection between the robot and the LAN is disconnected due to carelessness of the operator, the operation for retaining the parameters is performed consciously. Because there is no
There is a possibility that necessary parameters are deleted without being transferred to the EEPROM.

In addition, during teaching operation using a teaching pendant or the like, there is an inconvenience that data cannot be guaranteed when the teaching pendant is detached from the numerical controller main body.

Furthermore, in the numerical control device having the above-described configuration, double management of the information in the EEPROM and the information in the RAM is required, which causes a new problem that management becomes complicated. Therefore, for this purpose, for example, as disclosed in JP-A-63-285608, a user terminal i is provided and connected to a bus b via a user interface j (see FIG. 5). , EEPR
If there is any information that is not registered in the OM, the operator is prompted to transfer this information to the EEPROM, and the display is displayed to instruct the device whether the operator should register. Can be

However, if this method is used, the robot numerical controller
In the case of connecting to N, the amount of packet information increases to sequentially display unregistered information, increasing the load on the LAN, and also requiring emergency during emergency stop Sometimes, the flow of packet communication may be hindered.

(E. Means for Solving the Problems) In order to solve the above-described problems, the robot numerical control device of the present invention includes a CPU (Central Processing Unit) that interprets and executes the operation program of the robot. A volatile memory connected to the CPU, a communication connection circuit provided for performing communication with an external device, a communication state monitoring circuit for monitoring a communication state of the communication connection circuit, an operation program of the robot, and / or An electrically erasable non-volatile evacuation memory provided for storing parameter values related to the robot system and an evacuation memory provided between the CPU bus and evacuation memory, and evacuation from the CPU or communication connection circuit A write control circuit that outputs a command according to a predetermined write procedure to the evacuation memory when data is written to the evacuation memory. Upon detection of a normal one in which the content of the volatile memory is to be transferred via the write control circuit in the save memory.

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

(F. Embodiment) [FIGS. 1 to 4] In the following, details of a numerical control device for a robot according to the present invention will be described with reference to an illustrated embodiment.

(A. Basic configuration) [Fig. 1] Fig. 1 shows a numerical controller 1 for a robot connected to a LAN.
Is shown.

For the numerical controller 1, the CPU 2 uses the ROM via the bus 3
4. Access the EEPROM 5 and the RAM 6, and exchange information with the servo control unit 8 for the robot 7.

The numerical controller 1 is connected to the LAN via a LAN interface 9 so that an external instruction can be received via a trunk line 10 of the constituent network. With this configuration, the host 11 connected to the main line 10 can directly access the servo control unit 8.

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

In such a configuration, since the host 11 often controls the robot 7 through the LAN, the evacuation instruction for evacuation of data such as servo parameters to the EEPROM 5 is issued by the operator through the user terminal 12. It is easier to do this by the host 11 than instructing the host 11, and the timing of this evacuation is considered to be more appropriate in that the host 11 should determine it.

(B. Write Control Circuit) [FIGS. 2 and 3] 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 for the following reasons.

In other words, when writing data to EEPROM 5,
This is because, when the ROM 5 is used as an evacuation memory, if data is easily written into the evacuation memory, data stored in the EEPROM 5 may be destroyed when the CPU 2 runs away. In particular, DMA (Direct Memory Acc
ess) If the circuit is used in the LAN interface 9, the danger is even higher.

Therefore, in order to protect the stored information in EEPROM5, EEPRO
A write control circuit 14 for restricting the writing of data to M5 is provided, and data is written to EEPROM 5 via this, thereby preventing the above-described data destruction.

That is, the write control circuit 14 is only activated when the CUP2 or DMA circuit sends an intentional write command according to a predetermined procedure.
Since the data in the EEPROM 5 is not rewritten, data cannot be written to the EEPROM 5 by a direct write pulse from the CPU 2 or the DMA circuit. A predetermined signal must be generated.

For example, the easiest method is to use parallel interfaces (which are abbreviated as "PIO") 15 and 15 'as shown in FIG.

In the figure, 15 is a write control terminal (▲ ▼) of EEPROM5,
A read control input terminal (▲ ▼), a PIO interposed between the address input terminal (ADDRESS) and the bus 3, and 15 ′ between the data input / output terminal (DATA) of the EEPROM 5 and the bus 3 It is an intervening PIO.

Thus, the bus 3 and the EEPROM 5 are not directly connected,
IO15 and 15 'are provided between them, and writing and reading pulses are transmitted to and from the EEPROM 5 through the PIOs 15 and 15'. That is, since data can be written in the EEPROM 5 only by a signal in accordance with a predetermined write procedure, it is extremely unlikely that such a write procedure is accidentally executed when the CPU 2 runs away. Therefore,
Access to the EEPROM 5 is unlikely to occur accidentally in situations other than when the write command to the EEPROM 5 is created by the program of the CPU 2, and considerable reliability can be obtained with respect to the preservation of internal data.

By the way, an unnecessary write operation to the EEPROM 5 may be caused by a pulse generated when the power is turned on or off or an accidental pulse generated by initial setting of the PIOs 15 and 15 '.

To prevent this, FIG. 3A shows an example 14A of a write control circuit in which a write pulse is not generated unless a certain sequence is obtained from the CPU 2 or the DMA circuit.

The exchange of signals between the bus 3 and the EEPROM 5 consists of three PIOs
16 ₁ , 16 ₂ , and 16 ₃ . E
Address data relating EPROM5 is set via the PIO16 _1, data input and output is performed via the PIO16 _2.

PIO16 ₃ is related to writing and reading control for the EEPROM 5, the output signal (these S _a, S _b,
Notated as S _c and S _d . S _a of) is sent to the input terminal of the D input terminals and a subsequent stage of the AND gate 18 of the D-type flip-flop 17, the signal S _b is a clock input terminal for a clock input terminal and the shift register 19 of the D-type flip-flop 17 To be sent.

The signal _Sa 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 (this is referred to as “S ₁₈ ”) is sent to the shift register 19.

Output signals of the output S ₁₈ and the shift register 19 of the AND gate 18 (this referred to as "S _19".) Is sent to the AND gate 20, the
The output signal of the AND gate 20 (this is referred to as “S ₂₀ ”) is sent to the write control input terminal (WRITE) of the EEPROM 5 as a write control signal.

The signal _Sc is used as a signal for setting the D-type flip-flop 17 and resetting the shift register 19,
Signal S _d is designed to be sent to the read control input of EEPROM5 as a read control signal (READ).

Thus, generation of the write control signal by the circuit 14A, as is apparent from the time chart of FIG. 3 (B), a wave is generated in only the signal S ₁₈ at the rising edge of the signal S _a, which is in the shift register 19 S _b is the clock
Going to shift to the "S _19" from the first shift signal "S ₁₉ ^0" in accordance with the timing of.

The rising pulse signal S ₁₈ is input to the AND gate 20 while the pulse signal S ₁₉ after the shifting of a predetermined number were made are output (i.e., signal S _a is output at a predetermined timing In this case, a write control pulse is obtained only in such a case. In other cases, such a pulse is not obtained.

With the above circuit, limited physician signal according to a series of sequences from CPU2 or DMA circuit is not sent to the PIO16 ₃
It is impossible to write data to the EEPROM 5, so if there is no logical error in the program, the data in the EEPROM 5 will not be rewritten when the CPU 2 runs away, and the existing data will be protected.

Incidentally, it is needless to say that the effect of preventing unnecessary writing to EEPROM5 accidental pulse just using simple signal S ₁₈ without providing the shift register 19 in the above-mentioned circuit as a write control signal.

(C. Measures against accidents concerning LAN) [Fig. 4] For production lines, accidents in the campus 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 in which measures are taken against such a LAN accident.

In addition to the components described in FIG.
An N state detection unit 21 has been added.

That is, the LAN interface 9 is connected to the trunk line 10 to find out and process packets related to the robot 7, but when an accident occurs on the LAN, the carrier stops or the packet flow is poor. This phenomenon is observed as a phenomenon that the impedance of the signal line changes more than necessary, and the LAN state detection unit 21 constantly monitors such a change. If information about whether the LAN is operating normally or not can be included in the packet, such information may of course be used.

Then, when the LAN state detection unit 21 detects the occurrence of an accident, it treats this as an emergency and notifies the CPU 2 of the interruption by writing an interrupt ("INTR").

When the CPU 2 receives this INTR command, if no other priority tasks are being executed, the parameters and the like in the servo control unit 8 and the robot programs and the like in the RAM 6 are executed in accordance with the procedure described in advance in the ROM 4. Data about parameters and the like is transferred to the EEPROM 5 and saved.

As a result, even if control of each robot cannot be performed due to a LAN accident, data on the internal state of the robot at that time is guaranteed.

The concept similar to that of the LAN state detection unit 21 can be applied to a state detection circuit for monitoring the connection state between the teaching pendant and the numerical controller.

(G. Effects of the Invention) As is clear from the above description, the present invention provides a CPU that interprets and executes a robot operation program.
(Central processing unit), a volatile memory connected to the CPU, a communication connection circuit provided for performing communication with an external device, and a communication state monitoring circuit for monitoring a communication state of the communication connection circuit And an electrically erasable non-volatile evacuation memory provided for storing a robot operation program and / or parameter values related to the robot system, and provided between the CPU bus and the evacuation memory, A write control circuit that outputs a command according to a predetermined write procedure to the evacuation memory when data in the evacuation memory is written from the CPU or the communication connection circuit; and When an abnormality is detected, the contents of the volatile memory are transferred to the save memory via the write control circuit.

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

It should be noted that the above-described embodiment is merely an example of the numerical control device of the robot of the present invention, and the technical scope of the present invention should not be construed as being narrow only by this. For example,
In the above embodiment, the EEPROM is shown as the save memory.
Not limited to EEPROM devices using the avalanche effect,
RAM supported by battery backup circuit
It goes without saying that a non-volatile memory in a broad sense equivalent to an EEPROM can be used in its function, and all the embodiments without departing from the spirit of the present invention fall within the technical scope of the present invention. included.

[Brief description of the drawings]

1 to 4 show an embodiment of a numerical control device for a robot according to the present invention. FIG. 1 is a block diagram showing a numerical control device and a robot connected to a network, and FIG. FIG. 3 is a block diagram illustrating an example of a write control circuit, and FIG. 3 illustrates another example of the write control circuit.
(A) is a circuit block diagram, (B) is a schematic time chart diagram, FIG. 4 is a block diagram for explaining measures against network accidents, and FIG. 5 shows an example of a conventional robot numerical control device. It is a block diagram. DESCRIPTION OF SYMBOLS 1... Numerical control device of robot 2... CPU 3... Bus 5... Evacuation memory 6... Volatile memory 7... Robot 9. ... write control circuit, 15, 15 '... write control circuit, 14A ... write control circuit, 16 ₃ ... control output circuit, 17 ... delay circuit, 18 ... AND circuit, 16 ₃ , 17, 18 ... ... Control output circuit, 19 ... Delay circuit, 20 ... AND circuit, 21 ... Communication state monitoring circuit

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadanori Harada 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-63-285608 (JP, A) JP-A Sho 62-120504 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G05B 19/18

Claims (1)

(57) [Claims] A CPU (Central Processing Unit) for interpreting and executing an operation program of a robot, a volatile memory connected to the CPU, and a communication connection circuit provided for communicating with an external device. A communication state monitoring circuit for monitoring a communication state of the communication connection circuit; and an electrically erasable non-volatile evacuation memory provided for storing a robot operation program and / or parameter values related to the robot system. Between the CPU bus and the evacuation memory, and
A write control circuit that outputs a command according to a predetermined write procedure to the evacuation memory when data in the evacuation memory is written from the communication connection circuit, wherein the communication state monitoring circuit detects an abnormality in the communication state. A numerical controller for a robot, wherein when detected, the contents of a volatile memory are transferred to a save memory via a write control circuit.