System for collision avoidance of rotary atomizer

• US 20050046376A1
• Filed: 09/24/2003
• Published: 03/03/2005
• Est. Priority Date: 09/30/2002
• Status: Abandoned Application

• Current Assignee: Durr Systems Incorporated (Durr AG)
• Original Assignee: Durr Systems Incorporated (Durr AG)
• Inventors: Wildermuth, Dietmar, Hooge, Sven
• Application Number:
  US10/895,430
• Publication Number:
  US 20050046376A1
• Time in Patent Office: Days
• US Class Current: 318/650
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: G05B 19/4061 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 19/4062 Monitoring servoloop, e.g. overload of servomotor, loss of feedback or reference
• CPC Class Codes: G05B 2219/37297 Two measurements, on driving motor and on slide or on both sides of motor
• CPC Class Codes: G05B 2219/37624 Detect collision, blocking by measuring change of velocity or torque
• CPC Class Codes: G05B 2219/37625 By measuring changing forces in a time window
• CPC Class Codes: G05B 2219/37632 By measuring current, load of motor
• CPC Class Codes: G05B 2219/39186 Flexible joint
• CPC Class Codes: G05B 2219/39355 Observer, disturbance observer
• CPC Class Codes: G05B 2219/41372 Force estimator using disturbance estimator observer
• CPC Class Codes: G05B 2219/42161 One model for load, one model for motor inertia

Abstract

Monitoring method for a drive system with a motor and a moving part driven by the motor with the following steps: measurement of at least one drive-side motion quantity of the motor, measurement of at least one driven-side motion quantity of the moving part, and determination of an error signal as a function of the motion quantity measured on the drive side of the motor and the motion quantity measured on the driven side of the moving part.

Claims

1. A method for monitoring a drive system of a robot, more specifically a painting robot, with a motor and a moving part driven by the motor, with the following steps:

measuring at least one drive-side motion quantity of the motor;

measuring at least one driven-side motion quantity of the moving part; and

determining an error signal as a function of the motion quantities of the motor measured on the drive side and of the motion quantities of the moving part measured on the driven side.

2. The method according to claim 1 wherein the determining step is further comprises the following steps:

calculating a first comparison value for one of a drive force and a drive moment of the motor with reference to the motion quantity of the motor measured on the drive side;

calculating a second comparison value for one of a drive force and a drive moment of the motor with reference to the quantity of the moving part measured on the driven side;

comparing the first comparison value with the second comparison value; and

selectively generating the error signal in response to the comparing step.

3. The method according to claim 2 wherein the drive-side motion quantity measuring step is further defined by the velocity of the motor is measured and the first comparison value is calculated with reference to the measured velocity.

4. The method according to claim 2 wherein the drive-side motion quantity measuring step is further defined by the position of the motor is measured and the first comparison value is calculated with reference to the measured position of the motor.

5. The method according to claim 2 wherein the driven-side motion quantity measuring step is further defined by one of the position, the velocity, and the acceleration of the moving part is measured and the second comparison value is calculated for one of the drive force and the drive moment of the motor with reference to the one of the measured position, the measured velocity, and the measured acceleration of the moving part.

6. The method according to claim 2 wherein the second value calculating step is further defined by the second comparison value is calculated by a recursive computational method from one of the measured position, the measured velocity, and the measured acceleration of the moving part.

7. The method according to claim 2 wherein the drive system has a plurality of moving shafts, with one of the position, the velocity, and the acceleration being measured for the individual shafts, with the second comparison value being calculated separately for the individual shafts.

9. The method according to claim 7, wherein the second value calculating step is further defined by the second comparison value being calculated as a function of one of the positions, the velocities, and the accelerations of the plurality of shafts.

10. The method according to claim 7 wherein the error generating step is further defined by the error signal is generated separately for each shaft of the drive system.

11. The method according to claim 2 further comprising the step of:

determining a sliding mean value of the error signal.

8. (Cancelled)

12. A method for monitoring a drive system of a robot having a motor and a member moved by the motor, comprising the steps of:

generating a force with the motor to move the member;

communicating at least part of the moving force generated by the motor to the member with a drive shaft;

sensing at least one motion quantity of the drive shaft with a first sensor during the communicating step; and

sensing at least one motion quantity of the member with a second sensor during the communicating step.

13. The method of claim 12 further comprising the steps of:

determining a first force communicated by the drive shaft to the member in response to the sensed motion quantity of the drive shaft; and

determining a second force acting on the member in response to the sensed motion quantity of the member.

14. The method of claim 13 further comprising the step of:

comparing the determined first and second forces.

15. The method of claim 14 further comprising the step of:

stopping the motor in response to the comparing step.

16. The method of claim 15 wherein the stopping step is further defined by:

stopping the motor at a rate corresponding to a degree of difference between the first and second signals.

17. The method of claim 14 wherein the communicating step is further defined by:

communicating the moving force to the member and at least one other member with the drive shaft.

18. The method of claim 17 further comprising the steps of:

sensing at least one motion quantity of the other member with a third sensor during the communicating step; and

determining a third force acting on the other member in response to the sensed motion quantity of the other member.

19. The method of claim 18 wherein the comparing step is further defined by:

comparing the determined first, second and third forces.

20. The method of claim 19 wherein the comparing step is further defined by:

comparing a sum of the second and third forces with the first force.