Method for monitoring functional states a pressure driven actuator and pressure-actuatable actuator

Patent metadata

Field	Value
Publication number	US-10634243-B2
Application number	US-201715589044-A
Country	US
Kind code	B2
Filing date	May 8, 2017
Priority date	May 9, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The invention relates to a method for monitoring a functional state of a pressure-driven actuator which comprises an actuator compartment defined at least in portions by a flexibly deformable wall, the actuator being actuated by applying pressure to the actuator compartment by means of an operating pressure supply, a work process being carried out to actuate the actuator, which process is accompanied by the actuator transitioning from a starting configuration to an end configuration. The pressure the pressure applied to the actuator compartment is measured depending on time by means of a sensor apparatus during the transition from the starting configuration to the end configuration. The invention also relates to a pressure-driven actuator.

First claim

What is claimed is:

1. Method for operating a pressure-driven actuator which comprises an actuator compartment defined at least in portions by a flexibly deformable wall, the actuator being actuated by applying pressure to the actuator compartment by means of an operating pressure supply,
a work process being carried out to actuate the actuator, which process is accompanied by the actuator transitioning from a starting configuration to an end configuration,
characterised in that the pressure is measured depending on time by means of a sensor apparatus for measuring the pressure applied to the actuator compartment during the transition from the starting configuration to the end configuration, a characteristic curve (a, b, c, d) representing the progression of the pressure over time during the work process being determined and being stored in a storage apparatus,
wherein the determined characteristic curve is compared with a reference characteristic curve stored in the storage apparatus, and/or the deviation from the reference characteristic curve is determined,
wherein functional data which represent a functional state of the actuator are determined from the progression of the characteristic curve and/or the deviations from the reference characteristic curve, and wherein different functional data which represent different functional state of the actuator are determined from the different regions of the characteristic curve,
and wherein the operating pressure supply is controlled depending on the functional data.

2. Method according to claim 1 , characterised in that the pressure is only measured at specified time intervals (t 1 ; t 2 ) from the start of the work process and is compared with reference values stored in a storage apparatus, and/or the deviation from the reference values is determined.

3. Method according to claim 1 , characterised in that the pressure is continuously measured and the characteristic curve is compared with a specified and limited number of pressure reference values for distinct reference times (t 1 ;t 2 ), and/or the deviation from the reference values is determined.

4. Method according to claim 1 , characterised in that the operating pressure supply is controlled and/or the application of pressure to the actuator compartment is controlled such that the pressure applied to the actuator compartment corresponds to a target value predefined in each case at specified time intervals from the start of the work process, or in that the deviation from the target value predefined in each case is at most a predefined tolerance deviation.

5. Method according to claim 1 , characterised in that the operating pressure supply provides a specified output and/or a specified volumetric flow of working fluid in order to actuate the actuator to carry out the work process.

6. Method according to claim 1 , characterised in that, in addition to the work process, a calibration process is carried out in which a specified and reproducible load is applied to the actuator and the operating pressure supply provides a specified output and/or a specified volumetric flow of working fluid, the actuator transitioning from the starting configuration to the end configuration, and the time dependency of the pressure being determined in the form of a reference characteristic curve representing the progression of the pressure over time and being stored in a storage apparatus.

7. Method according to claim 1 , characterised in that a force acting on the actuator as a load is determined from the progression of the measured pressure over time.

8. Method according to claim 1 , characterised in that a plurality of work processes are cyclically repeated and are carried out in succession.

9. Pressure-driven actuator which comprises an actuator compartment defined at least in portions by a flexibly deformable wall such that the actuator can be actuated by applying pressure to the actuator compartment, the actuator transitioning from a starting configuration into an end configuration under deformation of the flexibly deformable wall, characterised in that a sensor apparatus is provided for the time-dependent measurement of the pressure applied to the actuator compartment, wherein a controller is provided which comprises means for:
carrying out a work process to actuate the actuator, which process is accompanied by the actuator transitioning from the starting configuration to the end configuration,
wherein the pressure is measured depending on time by means of the sensor apparatus for measuring the pressure applied to the actuator compartment during the transition from the starting configuration to the end configuration,
determining a characteristic curve (a, b, c, d) representing the progression of the pressure over time during the work process and storing the characteristic curve in a storage apparatus,
wherein the determined characteristic curve is compared with a reference characteristic curve stored in the storage apparatus, and/or the deviation from the reference characteristic curve is determined,
wherein functional data which represent a functional state of the actuator are determined from the progression of the characteristic curve and/or the deviations from the reference characteristic curve, and wherein different functional data which represent different functional state of the actuator are determined from the different regions of the characteristic curve,
and wherein the operating pressure supply is controlled depending on the functional data.

10. Pressure-driven actuator according to claim 9 , wherein the actuator is a vacuum pick-up device comprising a suction compartment forming the actuator compartment, to which a vacuum can be applied in order to pick up an object.

11. Pressure-driven actuator according to claim 9 , wherein the actuator is a vacuum tube lifter comprising a tube interior of a vacuum lifting tube forming the actuator compartment, wherein the vacuum lifting tube can be transferred from an extended starting configuration into a contracted end configuration by means of a vacuum being applied to the tube interior.

12. Method for operating monitoring a functional state of a pressure-driven actuator which comprises an actuator compartment defined at least in portions by a flexibly deformable wall, the actuator being actuated by applying pressure to the actuator compartment by means of an operating pressure supply,
a work process being carried out to actuate the actuator, which process is accompanied by the actuator transitioning from a starting configuration to an end configuration, characterised in that the pressure is measured depending on time by means of a sensor apparatus for measuring the pressure applied to the actuator compartment during the transition from the starting configuration to the end configuration, a characteristic curve (a, b, c, d) representing the progression of the pressure over time during the work process being determined and being stored in a storage apparatus,
wherein the determined characteristic curve is compared with a reference characteristic curve stored in the storage apparatus, and/or the deviation from the reference characteristic curve is determined,
wherein functional data which represent a functional state of the actuator are determined from the progression of the characteristic curve and/or the deviations from the reference characteristic curve, wherein the functional data represent a weight of an object actuated by the actuator, and wherein the operating pressure supply is controlled depending on the functional data.

13. Method for operating monitoring a functional state of a pressure-driven actuator which comprises a

Assignees

• Schmalz J Gmbh

Inventors

• Defranceski Aline
• Dunkmann Walter

Classifications

• B25J15/12

  with flexible finger members · CPC title

• F16H2061/0034

  Accumulators for fluid pressure supply; Control thereof · CPC title

• F16H61/0021 Primary

  Generation or control of line pressure · CPC title

• B25J15/0023

  Gripper surfaces directly activated by a fluid (flexible fingers B25J15/12) · CPC title

• B66C1/46

  by inflatable elements · CPC title