Method and system for operating a cyclic production machine in coordination with a loader or unloader machine

• US 8,423,159 B2
• Filed: 06/06/2007
• Issued: 04/16/2013
• Est. Priority Date: 02/06/2006
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: ABB Research Ltd. (ABB Limited)
• Inventors: Bosga, Sjoerd
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): Booker, Kelvin
• Application Number:
  US12/303,881
• Publication Number:
  US 20100234974A1
• Time in Patent Office: 2,141 Days
• Field of Search: 700/19, 901/15, 901/50, 901/6
• US Class Current: 700/19
• CPC Class Codes: B21D 43/02 Advancing work in relation to the stroke of the die or tool
• CPC Class Codes: B30B 1/266 Drive systems for the cam, eccentric or crank axis
• CPC Class Codes: B30B 15/14 Control arrangements for mechanically-driven presses
• CPC Class Codes: B30B 15/146 for synchronising a line of presses
• CPC Class Codes: B30B 15/148 Electrical control arrangements
• CPC Class Codes: G05B 19/41815 characterised by the cooperation between machine tools, manipulators and conveyor or other workpiece supply system, workcell
• CPC Class Codes: G05B 2219/39105 Manipulator cooperates with moving machine, like press brake
• CPC Class Codes: G05B 2219/45142 Press-line
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method for synchronizing a first machine of a manufacturing process section arranged to carry out a production cycle including a working part and a non-working part. The first machine is operated in conjunction with at least one second machine. The first machine carries out a process during the working part of the cycle on a workpiece that is loaded into and/or unloaded out of the first machine by the at least one second machine during the non-working part of each process cycle. Also, a system for carrying out the method and a computer program.

Claims

1. A method for operating a first machine of a manufacturing process section arranged to carry out a production cycle, said production cycle comprising a pressing part and a non-pressing part, which said first machine is operated in conjunction with at least one second machine and which said first machine carries out a process during a working part of the production cycle on a workpiece which is loaded into and/or unloaded out of said first machine by said at least one second machine during a non-working part of each process cycle, the method comprising:

synchronizing said first machine to said second machine dependent on a speed or position of said second machine by adaptively controlling a speed of said first machine to decelerate said first machine at a point before a start point after which unloading is permitted; and

synchronizing the speed of said first machine to said second machine by controlling the speed of said first machine and by decelerating said first machine at a start point before an estimated time at which said first machine shall reach the beginning of the unloading point stage towards zero speed and accelerating said first machine to reach an end point of a loading stage at a highest possible speed.

2. The method according to claim 1, further comprising:

synchronizing the speed of said first machine to said second machine by controlling the speed of said first machine and accelerating or decelerating the speed of the first machine according to an estimated time for said second machine to reach a beginning point or an end point of an unloading or loading stage of the production cycle.

3. The method according to claim 2, further comprising:

reversing said first machine after reaching a zero speed and subsequently accelerating said first machine in the forward direction so that the first machine reaches a zero speed for a second time such that said first machine is running at a highest possible speed when the first machine reaches the end point of the loading stage.

4. The method according to claim 2, further comprising:

upon detecting, after changing direction to the forward direction, that the loading stage shall be delayed, by holding said first machine at zero speed for a period of time before changing to positive torque and accelerating in the forward direction to full forward speed.

5. The method according to claim 2, further comprising:

upon detecting that the loading stage shall be delayed at a time before the deceleration time before unloading begins, by delaying the change in torque and start of deceleration to a later time point.

6. The method according to claim 2, further comprising:

upon detecting that the loading stage may begin early at a time after the deceleration has begun and before said first machine has changed to the forward direction, by reversing over a narrower angle and changing from negative torque to positive torque at an earlier point in time than planned,

or, upon detecting that the loading stage may begin early at a time before the deceleration time before unloading begins, by reversing over a still narrower angle and changing from negative torque to positive torque at a still earlier point in time than planned, before driving the press in the forward direction.

7. The method according to claim 2, further comprising:

upon detecting that the loading stage may begin early at a time after before the start of deceleration time before unloading, by starting deceleration at an earlier point in time, and earlier begins, by reversing said first machine after reaching a zero speed and subsequently accelerating in a forward direction so that the unloading-loading time is reduced.

8. The method according to claim 1, further comprising:

reversing said first machine after reaching a zero speed and subsequently accelerating in a forward direction so that said first machine is running at a highest possible speed when the first machine reaches an end point of a loading stage.

9. The method according to claim 1, further comprising:

upon detecting that the loading stage is being delayed, before the deceleration time at point has begun before beginning of unloading,

by subsequently changing from positive torque to negative torque and accelerating said first machine in a forward direction from an increased reverse angle or

after the deceleration has begun and before said first machine has changed from negative to positive torque to move in the forward direction, by instead continuing on negative torque and reversing over a greater angle and changing to positive torque at a later point in time than planned, and accelerating subsequently in the forward direction

so that said first machine reaches the end of the loading stage in the shortest possible time.

10. The method according to claim 1, further comprising:

reversing said first machine after reaching a zero speed and upon detecting before the deceleration time before unloading begins that the loading stage shall be delayed, by subsequently changing from negative torque to positive torque at a later point in time and thus accelerating said first machine in a forward direction so that the press reaches the end of the loading stage in the shortest possible time.

11. The method according to claim 10, further comprising:

utilizing in the calculation of start of deceleration point data describing the motion of said first machine during a finite or infinite number of previous cycles.

12. The method according to claim 1, further comprising:

estimating a time at which said second machine shall reach the beginning of the unloading point stage, and

calculating from the estimate a time at which said first machine shall reach the end point of the loading stage.

13. The method according to claim 12, further comprising:

determining a point in time at which to start reducing the speed of a forward motion of said second machine towards zero.

14. The method according to claim 1, further comprising:

calculating a point at which drive torque is changed from maximum negative to maximum positive such that the end point of the loading stage is reached at a desired time instant with as high speed as possible.

15. The method according to claim 14, further comprising:

calculating the desired time instant based on the actual position and/or speed of said second machine.

16. The method according to claim 15, further comprising:

calculating the desired time instant additionally utilizing data describing the motion of said second machine collected during a finite or infinite number of previous cycles.

17. The method according to claim 16, further comprising:

constraining the calculation of point R, or the calculation of start of deceleration point by that the motion of the first machine should not interfere with the motion of said second or other machine.

18. The method according to claim 1, further comprising:

calculating a point at which deceleration of said first machine is to be started such that the speed of said first machine at the start of the unloading phase and at the end of the loading phase is as high as possible, wherein the end of the loading phase point is reached at the moment loading is completed.

19. The method according to claim 1, further comprising:

operating said first machine and optimizing the speed of said first machine such that said first machine obtains the highest possible speed at the beginning of unloading of the non-pressing part of the process cycle, while at the same time minimizing the time difference between exit of the loader from the press and the end point of the loading stage.

20. The method according to claim 1, further comprising:

operating said first machine and optimizing the speed of said first machine such that said first machine obtains the highest possible speed at the beginning of unloading of the non-pressing part of the process cycle, while at the same time reaching a maximum speed at the end point of the loading stage.

21. The method according to claim 1, further comprising:

reversing either of said first machine or said at least one second machine during the loading/unloading part of the cycle.

22. The method according to claim 1, wherein said first machine is a mechanical press carrying out a pressing operation on the workpiece during the working or pressing part of the process cycle.

23. The method according to claim 1, wherein said second machine is a robot loader and/or unloader loading the workpiece into and/or out of said first machine during the loading/unloading part, the non-pressing part, of the process cycle.

24. A method for operating a first machine of a manufacturing process section arranged to carry out a production cycle, said production cycle comprising a pressing part and a non-pressing part, which said first machine is operated in conjunction with at least one second machine and which said first machine carries out a process during a working part of the production cycle on a workpiece which is loaded into and/or unloaded out of said first machine by said at least one second machine during a non-working part of each process cycle, the method comprising:

synchronizing said first machine to said second machine dependent on a speed or position of said second machine by adaptively controlling a speed of said first machine to decelerate said first machine at a point before a start point after which unloading is permitted

recovering energy from the first machine with regenerative braking;

recovering energy from the press and storing it in an energy recovery unit; and

smoothing electrical power consumption of a press.

25. A system, comprising:

a manufacturing process section comprising a first machine arranged to carry out a production cycle comprising a working part and a non-working part, said first machine being operated in conjunction with at least one second machine, said first machine carrying out a process during the working part of the cycle on a workpiece that is loaded into and/or unloaded out of said first machine by said at least one second machine during the non-working part of each process cycle; and

at least one control device arranged for adaptively controlling said first machine to decelerate said first machine from a point before the start point after which unloading is permitted dependant on a speed or position of said second machine thereby synchronizing said first machine to said second machine by controlling the speed of said first machine, wherein said at least one control device comprises a speed control configured to decelerate said first machine from a point before an estimated time at which said first machine shall reach the beginning of the unloading point stage towards zero speed and accelerating said first machine after reaching a zero speed to reach the end point of the loading stage at the highest possible speed.

26. The system according to claim 25, wherein said at least one control device comprises hardware and/or software for estimating a time at which said second machine shall arrive at the beginning of the unloading point stage to unload said first machine.

27. The system according to claim 25, wherein said at least one control device comprises hardware and/or software for estimating a time at which said second machine will arrive at the end point of the loading stage.

28. The system according to claim 25, wherein said at least one control device comprises a module configured to change the speed and/or direction of at least one drive motor of said first machine.

29. The system according to claim 25, wherein said at least one control device comprises a module configured to change torque magnitude and/or sign of at least one drive motor of said first machine.

30. The system according to claim 25, wherein at least one said first machine comprises a mechanical press comprising at least one electric drive motor, a drive control configured to control the motor, a ram, a flywheel, a clutch and a member for translating rotational motion of said flywheel in a first rotation direction into a linear motion of said ram arranged to be lowered and raised along a linear path for operating said press to carry out a press production cycle including a pressing part and one or more non-pressing parts of said cycle.

31. The system according to claim 25, wherein the mechanical press comprises a second drive motor or actuator arranged connected to said ram and by providing a control output to a drive control of said second drive motor such that the speed of said second drive motor is varied during at least one part of a said press production cycle.

32. The system according to claim 25, wherein at least one said first machine comprises a mechanical press comprising at least one electric drive motor, a drive control means for controlling the motor, a ram, and a member for translating rotational motion into a linear motion of said ram arranged to be lowered and raised along a linear path for operating said press to carry out a press production cycle including a pressing part and one or more non-pressing parts of said cycle.

33. The system according to claim 25, wherein at least one said first machine comprises a mechanical press comprising at least one electric drive motor, a drive control means for controlling the motor, a ram, and a member for translating rotational motion of said flywheel in a first rotation direction into a linear motion of said ram arranged to be lowered and raised along a linear path for operating said press to carry out a press production cycle including a pressing part and one or more non-pressing parts of said cycle.

34. The system according to claim 25, wherein at least one said first machine comprises a mechanical press comprising at least one electric drive motor, a drive control means for controlling the motor, a ram, and a member for translating rotational motion of said flywheel in a first rotation direction into a linear motion of said ram arranged to be lowered and raised along a linear path for operating said press to carry out a press production cycle including a pressing part and one or more non-pressing parts of said cycle.

35. The system according to claim 25, wherein said second machine comprises a robot loader and/or unloader loading the workpiece into and/or out of the first machine during the loading/unloading part of the process cycle.

36. The system according to claim 25, wherein said second machine comprises a transfer device.

37. The system according to claim 25, wherein either said first machine or said at least one second machine may be reversed during the loading and/or unloading part of the cycle.

38. The system according to claim 25, wherein said at least one control device comprises hardware and/or software for determining a point in time or reversing angle or speed at which to change the speed of a forward motion or a reverse motion of said second machine by changing the sign of the torque.

39. The system according to claim 25, wherein the at least one control unit comprises one or more computer programs for controlling the speed or torque of at least one drive motor of said first machine.

40. A computer program product, comprising:

a non-transitory computer readable medium; and

computer program instructions recorded on the computer readable medium and executable by a processor for carrying out a method for operating a first machine of a manufacturing process section arranged to carry out a production cycle, said production cycle comprising a pressing part and a non-pressing part, which said first machine is operated in conjunction with at least one second machine and which said first machine carries out a process during a working part of the production cycle on a workpiece which is loaded into and/or unloaded out of said first machine by said at least one second machine during a non-working part of each process cycle, the method comprising;

synchronizing said first machine to said second machine dependent on a speed or position of said second machine by adaptively controlling a speed of said first machine to decelerate said first machine at a point before a start point after which unloading is permitted; and

synchronizing the speed of said first machine to said second machine by controlling the speed of said first machine and by decelerating said first machine at a start point before an estimated time at which said first machine shall reach the beginning of the unloading point stage towards zero speed and accelerating said first machine to reach an end point of a loading stage at a highest possible speed.

41. A method for operating a first machine of a manufacturing process section arranged to carry out a production cycle, said production cycle comprising a pressing part and a non-pressing part, wherein said first machine is operated in conjunction with at least one second machine, and wherein said first machine carries out a process during a working part of the production cycle on a workpiece that is loaded into and/or unloaded out of said first machine by said at least one second machine during a non-working part of each process cycle, the method comprising:

controlling operation of said first machine so as to depend on a speed or position of said second machine by adaptively controlling a speed of said first machine to decelerate said first machine at a point before a start point after which unloading is permitted.