Real time control method for a robot controller

• US 6,301,634 B1
• Filed: 01/12/2000
• Issued: 10/09/2001
• Est. Priority Date: 07/05/1996
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group), Seiko Seiki COLK Limited
• Inventors: Gomi, Kazuhiro, Shioda, Toshimi, Yokoshima, Norio, Miyazawa, Hiroshi, Okuyama, Masayuki
• Primary Examiner(s): Beausoleil, Robert
• Assistant Examiner(s): PHAN, RAYMOND NGAN
• Application Number:
  US09/482,387
• Time in Patent Office: 636 Days
• Field of Search: 710/61, 710/104, 710/107, 710/126, 710/131, 710/129, 710/262, 710/267, 710/268, 710/269, 712/220, 712/228, 712/231, 712/232, 712/233, 712/235, 712/241, 712/247, 709/102, 709/106, 709/107, 709/108
• US Class Current: 710/267
• CPC Class Codes: B25J 9/161 Hardware, e.g. neural networks, fuzzy logic, interfaces, processor
• CPC Class Codes: G05B 2219/31293 Enter size measurements, store in data base, analyze and identify in size data group
• CPC Class Codes: G05B 2219/33095 External clock delivers interrupts for real time execution of programs
• CPC Class Codes: G05B 2219/34258 Real time system, qnx, works together with non real time system, windows nt
• CPC Class Codes: G05B 2219/34266 Windows-95
• CPC Class Codes: G05B 2219/34338 Execute control tasks, programs as well as user, application programs
• CPC Class Codes: G05B 2219/34383 Dynamic preemptive, special event register manages time slices for applications
• CPC Class Codes: G05B 2219/40389 Use robot control language also to write non robotic user, application programs

Abstract

A robot controller and its control method use a generic personal computer and a PC operating system. The controller 10 comprises the following: a task-switching unit 30 that switches tasks on a pre-emptive basis; an external interrupt generator 50 that uses an external timer to generate interrupts at specified fixed time intervals; an event drive unit 40 that performs event drive processing in synchronization with the interrupts generated by the external interrupt generator 50; an event registration unit 60 that registers the fact that the application program which performs processing in response to the occurrence of the event is waiting for the occurrence of the event; an event resource state storage unit 70 that stores event resource states in order to keep track of and recall the occurrence of events; an event resource state update unit 80 that updates the conditions of event resources stored in the event resource state storage unit 70; and a swap-out prevention unit 90 that prevents the swapping out of programs for which real time processing is required.

Claims

1. A real time control method for executing processing associated with occurrences of events in a robot controller utilizing a generic operating system having a pre-emptive multi-tasking function comprising:

using an external timer to generate interrupt signals on a regular basis at fixed time intervals sufficient for the execution of real time processing; and

detecting events in synchronization with said interrupt signals that are generated in said external interrupt generation step and performing event drive processing whereby said generic operating system is directed to switch to a task which executes processing associated with an event detected in said detecting step.

2. The control method of claim 1, further comprising:

registering an event, an occurrence of which is being waited for by a program that executes processing associated with said event occurrence;

detecting the occurrence of an event registered in said event registration step; and

directing said generic operating system to switch to a task which executes a program that is waiting for occurrence of said event registered in said event registration step.

3. The control method of claim 2 further comprising

preventing swapping out of a program by directing said generic operating system to start a program, on a regular basis at specified time intervals said program having registered the fact that it is waiting for the occurrence of an event.

4. The control method of claim 1, wherein

said detected events include at least one of a change in hardware resources of a robot controlled by said controller, a change in output data which enables a program for controlling manipulator actions, and a change in output data which enables peripheral devices to perform synchronization and communication.

5. The control method of claim 4, further comprising:

storing in a shared memory area that can be referenced and updated by multiple tasks, event resource states in order to keep track of said detected events;

updating said event resource states stored in said shared memory based upon changes in said detected events; and

updating a hardware resource based upon event resource states that have been updated in said event resource state update step.

6. A medium readable by a machine embodying a program of instructions executable by said machine to perform a real time control method for executing processing associated with occurrences of events in a robot controller utilizing a generic operating system having a pre-emptive multi-tasking function, said control method comprising the steps of:

using an external timer to generate interrupt signals on a regular basis at fixed time intervals sufficient for the execution of real time processing; and

detecting events in synchronization with said interrupt signals that are generated in said external interrupt generation step and performing event drive processing whereby said generic operating system is directed to switch to a task which executes processing associated with an event detected in said detecting step.

7. The medium of claim 6 wherein said control method further comprises:

registering an event, an occurrence of which is being waited for by a program that executes processing associated with said event occurrence;

detecting the occurrence of an event registered in said event registration step; and

directing said generic operating system to switch to a task which executes a program that is waiting for occurrence of said event registered in said event registration step.

8. The medium of claim 7 wherein in said control method:

said detected events include at least one of a change in hardware resources of a robot controlled by said controller, a change in output data which enables a program for controlling manipulator actions, and a change in output data which enables peripheral devices to perform synchronization and communication.

9. The medium of claim 8 wherein said control method further comprises:

storing in a shared memory area that can be referenced and updated by multiple tasks, event resource states in order to keep track of said detected events;

updating said event resource states stored in said shared memory based upon changes in said detected events; and

updating a hardware resource based upon event resource states that have been updated in said event resource state update step.

10. The medium of claim 7 wherein said control method of claim 9 further comprises:

preventing swapping out of a program by directing said generic operating system to start a program, on a regular basis at specified time intervals, said program having registered the fact that it is waiting for occurrence of an event.