Positioning apparatus gravity compensation device and method for compensating gravitational forces

• US 7,551,970 B2
• Filed: 07/29/2004
• Issued: 06/23/2009
• Est. Priority Date: 08/07/2003
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Tousain, Robertus Leonardus, Stommen, Bernard Jacob Andries
• Primary Examiner(s): BARNES-BULLOCK, CRYSTAL JOY
• Application Number:
  US10/567,220
• Publication Number:
  US 20060259165A1
• Time in Patent Office: 1,790 Days
• Field of Search: 332/83, 333/98, 335/03, 700/56, 700 61- 63, 700/279, 700/280, 318/632, 318/568.1, 318/649
• US Class Current: 700/61
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/40255 End effector attached to cable for gravity balance suspension
• CPC Class Codes: G05B 2219/41114 Compensation for gravity, counter balance gravity

Abstract

The present invention relates to a positioning apparatus. The positioning apparatus comprises at least one position sensor, at least one position controller and at least one position actuator, wherein the or each position sensor measures the position of a position-controlled device, wherein the or each position controller uses measurement signals provided by the or each position sensor as input signals, and wherein output signals generated by the or each position controller are used by the or each position actuator to control the position of said position-controlled device. The positioning apparatus further comprising a gravity compensation device compensating gravitational forces acting on said position-controlled device, wherein the gravity compensation device includes at least one gravity compensation controller and at least one gravity compensation actuator, wherein the or each gravity compensation controller uses the output signals generated by the or each position controller as input signals, thereby generating output signals used by the or each gravity compensation actuator to compensate gravitational forces acting on said position-controlled device.

Claims

1. Positioning apparatus comprising:

at least one position sensor,

at least one position controller and

at least one position actuator,

wherein the or each position sensor measures the position of a position-controlled device,

wherein the or each position controller uses measurement signals provided by the or each position sensor as input signals,

wherein output signals generated by the or each position controller are used by the or each position actuator to control the position of said position-controlled device,

the positioning apparatus further comprising a gravity compensation device compensating gravitational forces acting on said position-controlled device, wherein the gravity compensation device includes at least one gravity compensation controller and at least one gravity compensation actuator, wherein the or each gravity compensation controller uses the output signals generated by the or each position controller as input signals, thereby generating output signals used by the or each gravity compensation actuator to compensate gravitational forces acting on said position-controlled device,

wherein the gravity compensation actuator comprises a spring, a string, a pulley and a motor.

2. Positioning apparatus according to claim 1, wherein the spring is attached with a first end preferably to the position-controlled device and with a second end to the string.

3. Positioning apparatus according to claim 1, wherein the string is wound around the pulley, wherein the pulley is driven by the motor, and wherein the motor is controlled by the output signals generated by the gravity compensation controller.

4. Positioning apparatus according to claim 1, wherein the pulley is driven by the motor in a way that the tension in the spring is kept constant and equal to the gravitational forces acting on said position-controlled device.

5. Positioning apparatus comprising:

at least one position sensor,

at least one position controller and

at least one position actuator,

wherein the or each position sensor measures the position of a position-controlled device,

wherein the or each position controller uses measurement signals provided by the or each position sensor as input signals,

wherein output signals generated by the or each position controller are used by the or each position actuator to control the position of said position-controlled device,

the positioning apparatus further comprising a gravity compensation device compensating gravitational forces acting on said position-controlled device, wherein the gravity compensation device includes at least one gravity compensation controller and at least one gravity compensation actuator, wherein the or each gravity compensation controller uses the output signals generated by the or each position controller as input signals, thereby generating output signals used by the or each gravity compensation actuator to compensate gravitational forces acting on said position-controlled device,

the gravity compensation device further including two gravity compensation controllers, wherein a first gravity compensation controller of the two gravity compensation controllers uses the output signals generated by the position controller as input signals, wherein a second gravity compensation controller of the two gravity compensation controllers uses the output signals generated by the first gravity compensation controller as input signals, and wherein output signals from said second gravity compensation controller are used to control the gravity compensation actuator,

wherein the output signals generated by the first gravity compensation controller are summed with a position setpoint signal of said position controller, wherein the resulting signal is used as setpoint for said second gravity compensation controller.

6. Positioning apparatus comprising:

at least one position sensor,

at least one position controller and

at least one position actuator,

wherein the or each position sensor measures the position of a position-controlled device,

wherein the or each position controller uses measurement signals provided by the or each position sensor as input signals,

wherein output signals generated by the or each position controller are used by the or each position actuator to control the position of said position-controlled device,

the positioning apparatus further comprising a gravity compensation device compensating gravitational forces acting on said position-controlled device, wherein the gravity compensation device includes at least one gravity compensation controller and at least one gravity compensation actuator, wherein the or each gravity compensation controller uses the output signals generated by the or each position controller as input signals, thereby generating output signals used by the or each gravity compensation actuator to compensate gravitational forces acting on said position-controlled device,

the gravity compensation device further including two gravity compensation controllers, wherein a first gravity compensation controller of the two gravity compensation controllers uses the output signals generated by the position controller as input signals, wherein a second gravity compensation controller of the two gravity compensation controllers uses the output signals generated by the first gravity compensation controller as input signals, and wherein output signals from said second gravity compensation controller are used to control the gravity compensation actuator,

wherein the second gravity compensation controller uses the measurement signal of a motor position sensor as input signal, wherein said motor position sensor measures the position of the motor of said gravity compensation actuator.

7. Gravity compensation device for compensating gravitational forces acting on a position-controlled device, wherein the position of said position-controlled device is measured by at least one position sensor and controlled by at least one position controller, the device having at least one gravity compensation controller and at least one gravity compensation actuator, wherein the or each gravity compensation controller uses the output signals generated by the or each position controller as input signals, thereby generating output signals used by the or each gravity compensation actuator to compensate gravitational forces acting on said position-controlled device, wherein the gravity compensation actuator comprises a spring, a string, a pulley and a motor.

8. Gravity compensation device according to claim 7, wherein the spring is attached with a first end preferably to the position-controlled device and with a second end to the string.

9. Gravity compensation device according to claim 7, wherein the string is wound around the pulley, whereby the pulley is driven by the motor, and whereby the motor is controlled by the output signals generated by the gravity compensation controller.

10. Gravity compensation device according to claim 7, wherein the pulley is driven by the motor in a way that the tension in the spring is kept constant and equal to the gravitational forces acting on said position-controlled device.

11. Gravity compensation device for compensating gravitational forces acting on a position-controlled device, wherein the position of said position-controlled device is measured by at least one position sensor and controlled by at least one position controller, the gravity compensation device comprising at least one first gravity compensation controller and at least one gravity compensation actuator, wherein the at least one first gravity compensation controller uses the output signals generated by the at least one position controller as input signals, thereby generating output signals used by the at least one gravity compensation actuator to compensate gravitational forces acting on said position-controlled device, the device further comprising a second gravity compensation controller, wherein the at least one first gravity compensation controller uses the output signals generated by the position controller as input signals, wherein the second gravity compensation controller uses the output signals generated by the at least one first gravity compensation controller as input signals, and wherein output signals from said second gravity compensation controller are used to control the gravity compensation actuator, wherein the output signals generated by the first gravity compensation controller are summed with a position setpoint signal of said position controller, whereby the resulting signal is used as setpoint for said second gravity compensation controller.

12. Gravity compensation device for compensating gravitational forces acting on a position-controlled device, wherein the position of said position-controlled device is measured by at least one position sensor and controlled by at least one position controller, the gravity compensation device comprising at least one first gravity compensation controller and at least one gravity compensation actuator, wherein the at least one first gravity compensation controller uses the output signals generated by the at least one position controller as input signals, thereby generating output signals used by the at least one gravity compensation actuator to compensate gravitational forces acting on said position-controlled device, the gravity compensation device further comprising a second gravity compensation controller, wherein the at least one first gravity compensation controller uses the output signals generated by the position controller as input signals, wherein the second gravity compensation controller uses the output signals generated by the at least one first gravity compensation controller as input signals, and wherein output signals from said second gravity compensation controller are used to control the gravity compensation actuator, wherein the second gravity compensation controller uses the measurement signal of a motor position sensor as input signal, whereby said motor position sensor measures the position of the motor of said gravity compensation actuator.

13. Method for compensating gravitational forces acting on a position-controlled device, whereby the position of said position-controlled device is measured by at least one position sensor and controlled by at least one position controller, wherein at least one gravity compensation controller uses output signals generated by the or each position controller as input signals thereby generating output signals used by at least one gravity compensation actuator to compensate gravitational forces acting on said position-controlled device, wherein the gravity compensation actuator comprises a spring, a string, a pulley and a motor, whereby the spring is attached with a first end to the position-controlled device and with a second end to the string, wherein the string is wound around the pulley, and wherein the pulley is driven by the motor using the output signals generated by the gravity compensation controller in a way that the tension in the spring is kept constant and equal to the gravitational forces acting on said position-controlled device.

14. Method for compensating gravitational forces acting on a position-controlled device, whereby the position of said position-controlled device is measured by at least one position sensor and controlled by at least one position controller, whereby at least one gravity compensation controller uses output signals generated by the or each position controller as input signals thereby generating output signals used by at least one gravity compensation actuator to compensate gravitational forces acting on said position-controlled device,

wherein two gravity compensation controllers are used, a first gravity compensation controller using the output signals generated by the position controller as input signals and a second gravity compensation controller using the output signals generated by the first gravity compensation controller as input signals, output signals of said second gravity compensation controller being used to control the gravity compensation actuator, output signals generated by the first gravity compensation controller being summed with a position setpoint signal of said position controller, whereby the resulting signal is used as setpoint for said second gravity compensation controller, and the second gravity compensation controller uses the measurement signal of a motor position sensor as input signal, whereby said motor position sensor measures the position of the motor of said gravity compensation actuator.

15. A positioning apparatus comprising:

at least one position sensor, at least one position controller, at least one position actuator and at least one gravity compensation device,

the gravity compensation device comprising at least one gravity compensation controller and at least one gravity compensation actuator and being capable of compensating gravitational forces acting on a position-controlled device,

wherein the position sensor is configured to measure a position of the position-controlled device,

the position controller is capable of using measurement signals provided by the position sensor as input signals to generate output signals, and

the output signals generated by the position controller are manipulated variable output signals used by the position actuator to control the position of the position-controlled device and further serve as signals inputting a controlled variable to the at least one gravity compensation controller,

thereby generating output signals used by the gravity compensation actuator to compensate gravitational forces acting on the position-controlled device.

16. The positioning apparatus of claim 15, wherein the gravity compensation device further includes a second gravity compensation controller, wherein the gravity compensation controller uses the output signals generated by the position controller as input signals of a controlled variable, and wherein the second gravity compensation controller uses the output signals generated by the first gravity compensation controller as input signals, and wherein output signals from said second gravity compensation controller are used to control the gravity compensation actuator.

17. A gravity compensation device for compensating gravitational forces acting on a position-controlled device, wherein the position of the position-controlled device is measured by at least one position sensor and controlled by at least one position controller, the gravity compensation device comprising at least one gravity compensation controller and at least one gravity compensation actuator, wherein the gravity compensation controller uses output signals of a manipulated variable generated by the position controller as input signals of a controlled variable, thereby generating output signals used by the or each gravity compensation actuator to compensate gravitational forces acting on the position-controlled device.

18. The gravity compensation device of claim 17, comprising a second gravity compensation controller, wherein the gravity compensation controller uses the output signals generated by the position controller as input signals of a controlled variable, wherein the second gravity compensation controller uses the output signals generated by the first gravity compensation controller as input signals, and wherein second gravity compensation controller output signals from the second gravity compensation controller are used to control the gravity compensation actuator.

19. A method for compensating gravitational forces acting on a position-controlled device, the method comprising:

measuring a position of the position-controlled device using a position sensor,

controlling the position-controlled device using a position controller to generate output signals of a manipulated variable from the measured position,

using the output signals generated by the position controller as a controlled variable to generate output signals of a gravity compensation controller,

using the output signals of the gravity compensation controller to control a gravity compensation actuator and compensate gravitational forces acting on the position-controlled device thereby.

20. The method of claim 19 wherein the step of using the output signals of the gravity compensation controller to control a gravity compensation actuator comprises sending the output signals of the gravity compensation controller directly to the gravity compensation actuator.

21. The method of claim 19 wherein the step of using the output signals of the gravity compensation controller to control a gravity compensation actuator comprises sending the output signals of the gravity compensation controller to a second gravity compensation controller.