DD244837A1 - POSITIONING SYSTEM FOR THE GROB FINE CONTROL OF MICRORECHNER CONTROLLED MANIPULATORS - Google Patents

Abstract

The invention relates to a positioning system for coarse-fine control micro-computer-controlled manipulators, which can be used preferably in the Precisiongeraeteetechnik, for example, for automated circuit production application. The aim of the invention is to reduce the amount of hardware components by means of non-linear control characteristic and to prevent the discontinuities resulting from the changeover from microcomputer position control to hardware storage in the setpoint specification. The object of the invention is to ensure a harmonious sequence of movements for the global driving process and the transition to local fine positioning. According to the invention, the object is achieved in that the microcomputer predefines a speed setpoint curve which corresponds to the reduction of the phase curve v (f) by the approximated profile of a load-side non-linearly amplified end position sensor signal and corresponds on the output side to the mixing point for additive superimposition with the non-linearly amplified end position sensor signal and On the output side of the mixing point for additive superimposition with the non-linearly amplified Endlagensensorsignal zufuehrt, which is connected to the Verzoegerungsglied, the Sollglaettung, the speed control circuit with an electronic Drehzahlistwerterfassung and the underlying current control circuit. Fig. 1

Description

embodiment

The PI controller 21 on the input side, the delay element 14 for smoothing the output of the mixing point 11, for the continuous superimposition of the microcomputer control curve UDA and the non-linearly amplified signal of the load side arranged Endlagenensors UELS, upstream. The output signal of the end position sensor has a linearity region in the vicinity of the zero crossing, which is converted into a function (Δφ ^2/3 ) in a logarithm amplifier 12. For small rotation angles (sinip = φ) , the profile of the non-linearly amplified end position sensor signal UELS with the phase curve

UDA1 = f- - - · - l »J" l - - -! 2-1-Il

Γ. / π

= ω · sin -

L \ 2

<PB / J

is identical and is mathematically approximated as a function of φ 1 UDA2. The microcomputer control curve UDA results from the reduction of the phase curve UDA1 by the course of the approximated, non-linearly amplified end position sensor signal UELS. ,

On the output side of the PI controller, a current control loop 30 is underlain, which controls the motor 1 with the signal which corresponds to the real positional conditions at the load 4 in the end position range. On the primary side, there is an incremental encoder 2 on the motor, whose signals are used for pulse quadrupling and interference signal suppression 23 and are fed to the electronic speed actual value detection 22 and to the forward / reverse discriminator 15. By means of the decrementing of the value preset in the CTC channels, on the arrival of the pre-reverse pulses (Vl, Rl), the microcomputer control loop is closed.

The gearbox 3 to be used is braced without play in the end positions by stop springs. When creating the microcomputer control curve UDA, it must be taken into account that systematic errors (clearance angle of the transmission) occur in accordance with the desired positioning angle, which errors can be compensated for by selective feedforward control in the theoretical travel curve.

Claims (2)

1. Positioning system for coarse fine control of microcomputer-controlled manipulators, consisting of a subordinate speed and current control loop, using a primary-side electronic speed and Lageistwerterfassung means incrementalem measuring system and a secondary-side Lageistwerterfassung means incrementalem measuring system and a secondary-side actual position detection by at least one limit sensor characterized in that the microcomputer (10) specifies a speed setpoint curve with targeted feedforward control (transmission clearance angle) as a function of the primary-side actual position (UDA), which corresponds to the reduction of the phase curve (UDA 1) by the approximated characteristic of a non-linearly amplified end position sensor signal (UDA2) wherein the mixing point (11) for the additive superimposition of the microcomputer control curve (UDA) with the non-linearly amplified signal of the load-side arranged end position sensor (UELS) before the delay Gl ied to setpoint smoothing (14) is arranged, which join the speed and current control circuit (20,30). 2. Positioning system according to item 1, characterized in that by the non-linear amplification, the linearity range of the end position sensor (U <plST), in setpoint position environment, the phase curve (UDA 1) corresponds. For this 1 page drawing Field of application of the invention The invention relates to a positioning system for coarse fine control of microcomputer-controlled manipulators which can be used preferably in precision equipment technology. Characteristic of the known solutions It is known that several control circuits are cascaded (position-speed-current control loop) to realize a high dynamics of controlled drive systems. In order to be able to position both time-optimized and to meet the requirements for accuracy and stability, a distinction must be made between coarse positioning and local fine positioning. In the global driving process, the microcomputer specifies a non-linear speed setpoint curve as a function of the primary-side position, which is converted digital-analogically and, after the setpoint smoothing, supplies the speed controller with the delayed setpoint on the input side. On the primary side of the mechanical system, an incremental encoder is arranged, the signals of which are used both for electronic speed actual value detection and for the actual position value. If a certain positioning angle preset in the CTC channels is reached, an interrupt switches to a secondary-side hardware position control. It is known that both the switching of the controller parameters, when using only one analog controller, as well as the switching by means of setpoint switch of two independently existing controllers realized. In both cases, however, in addition to the switching uncertainties, the strong difference in the control deviations between-tracking control, in the global driving process, and the fixed value control, in the local fine positioning, crucial for a strong stimulation of the mechanical system at the switching time. Due to the variable friction and play conditions, due to wear and resistance moments, discontinuities occur in the setpoint level, if only the primary side position values or control variables are obtained because the primary-measured position does not match the practically achieved secondary position. Object of the invention The aim of the invention is to reduce the complexity of hardware components by means of non-linear control characteristic and to prevent the discontinuities resulting from the system structure switching in the setpoint specification. Thus, the high demands on fast Präzisionspositioniersysteme with regard to the positioning, the accuracy and stability of retraction into the target position and the minimum stress on all mechanical working organs of the manipulator can be better met. Explanation of the essence of the invention The object of the invention is to ensure a harmonic course of movement both for the global driving process and for the transition to the local fine positioning without switching the system structure and to realize the control of the motor with the signal corresponding to the real positional conditions at the load. According to the invention, the object is achieved in that the microcomputer specifies a speed setpoint curve as a function of the primary-side actual position, which corresponds to the reduction of the theoretically optimal phase curve ω (φ) by the approximated course of a non-linearly amplified Endlagenensensorssignals, and these outputs a mixing point, the the continuous superposition of the speed setpoint curve with the non-linearly amplified signal of a load side arranged end position sensor is used. After setpoint smoothing, the PI controller carries out the setpoint / actual value comparison both for the global driving process and for the local fine positioning with fixed controller parameters and controls the motor in the end position range according to the secondary position deviation via the current control circuit.