Automatic control system

• US 5,128,599 A
• Filed: 09/25/1990
• Issued: 07/07/1992
• Est. Priority Date: 09/25/1989
• Status: Expired due to Fees

• Current Assignee: Mannesmann Rexroth GmbH (Robert Bosch GmbH)
• Original Assignee: Mannesmann Rexroth GmbH (Robert Bosch GmbH)
• Inventors: Ditter, Gerhard, Nikolaus, Heinrich
• Primary Examiner(s): Ip, Paul
• Application Number:
  US07/588,009
• Time in Patent Office: 651 Days
• Field of Search: 318/561, 318/567, 318/568.14, 318/568.2, 318/601, 318/663, 318/671, 137/625.63, 91/361, 364/424.1, 364/426.02, 123/432, 123/589, 303/95, 303/96, 303/97, 303/100, 303/103, 188/181 C
• US Class Current: 318/685
• CPC Class Codes: G05B 19/427 Teaching successive positions by tracking the position of a joystick or handle to control the positioning servo of the tool head, master-slave control G05B19/423 takes precedence
• CPC Class Codes: G05B 2219/33079 Table with functional, weighting coefficients, function
• CPC Class Codes: G05B 2219/34337 Manual to automatic, tracer
• CPC Class Codes: G05B 2219/34365 After interrupt of operation, do other task and go on - resume operation
• CPC Class Codes: G05B 2219/36382 Speed of read in of data as function of available power for driving servo, safety
• CPC Class Codes: G05B 2219/36471 Recording speed different from playback speed
• CPC Class Codes: G05B 2219/37491 Compensate non linearity of transducer by lookup table
• CPC Class Codes: G05B 2219/37619 Characteristics of machine, deviation of movement, gauge,
• CPC Class Codes: G05B 2219/41301 Pilot valve, linear fluid control valve and power cylinder

Abstract

An automatic control including a memory is provided to be loaded with positional data for the automatic control of a cycle of motions of preferably a plurality of power members. The speed reading the data in and out is freely selectable. Accordingly programming a cycle of motions may be performed in a slow motion process, whereas the speed of reading out the data is selected such that an optimum operational speed is obtained. In addition to the automatic speed control a manual control is provided to interrupt the cycle motion of the automatic control to manually adjust the position or the power member. In returning to the automatic control the further cycle of motion is taken up again where it has been interrupted.

Claims

1. An automatic control system for controlling a cycle of motions of t least a power member controlled by a servo device, in particular for a plurality of hydraulic power units to be simultaneously actuated, comprising a control transmitter for setting desired motional values, a control circuit for actuating said servo device, a loop for feeding back positional data defining a sequence of positions of the power member in operation, and a memory including at least one random memory for reading-in and out said positional data which define said cycle of motions, characterized in that a random memory each is correlated to each power member, that the data defining said positions successive in time and corresponding in time to said cycle of motions are read-in identical memory location in each random memory and that the speed of reading-in and out said positional data is freely selectable by a time selecting DPTR signal controlled by a pedal such that the switching time between the memory locations in each random memory is modified by the DPTR signal, and when the pedal is actuated to make the DPTR signal indefinite, the reading out of said positional data from the memory locations is stopped to allow the last positional data read-out from each random memory to be superimposed with desired magnitudes adjusted by said control transmitter.

2. The system of claim 1 wherein the positional actual data delivered by said power member are cyclically read in a memory location, wherein each preceding data is erased, until the switching time selected by the DPTR signal is terminated resulting in loading the preceding memory location with data previously written-in and writing-in data in the next following memory location.

3. The system of claim 1 wherein the positional data from the memory defining desired magnitudes to actuate said power member are compared with actual data indicating the positions of the power member to define an error signal to control said servo device actuating said power member.

4. The system of claim 1 wherein a response curve of said servo device is loaded in a table memory which is loaded with a desired magnitude corresponding to a position magnitude read-out from said random memory to actuate said power member and from which a signal is read-out corresponding to said desired magnitude which is delivered from a microprocessor to said servo device.

5. The system of claim 4 wherein said positional data read-out from said random memory are superimposed with desired magnitudes which are adjustable at a control transmittor.

6. The system of claim 5 wherein a pedal is provided which when being actuated locks switching over the memory lo-cations in said memories and wherein said positional data read-out from the memory latest are superimposed with desired magnitudes adjusted by said control transmitter.

7. The system of claim 1 wherein said DPTR signal is superimposed with a limit signal to slow down the read-out speed of data from said memory when a hydraulic system receives less fluid volume than required.

8. The system of claim 7 wherein the limit signal is generated by the valve in its open position when the pump delivery volume is less than required.

9. The system of claim 7 wherein said limit signal is generated when the power of the pump drive means is less than required.

10. The system of claim 1 wherein the difference of the positional data defining desired magnitudes read-out from said memory and positional data generated by the power member defining actual magnitudes is generated and the positional data read-out from the memory are superimposed with the difference signal.

11. The system of claim 1 wherein said DPTR signal is used as a correcting variable signal for a closed loop control.