DD282307A5 - CONTROL CIRCUIT FOR A PEDESTRIAN MOTORIZED POSITIONING SYSTEM WITH POSITION SENSOR - Google Patents

Abstract

The invention relates to the control of a stepper motor moving positioning with position sensor by the evaluation of its analog output signal. The aim of the invention is to position with minimal technical effort by step motor synchronous evaluation of the output signal of a position sensor. This is solved according to the invention by comparing the nth and * mesz values, respectively. These are fed via a subtractor to a trigger with an adjustable response threshold. The trigger controls via a gate circuit the Meszwertaufnahme and movement of the position sensor {circuit; Control; Positioning; Stepper motor; Position sensor; Output signal; subtractor; Comparison; trigger; gate}

Description

For this 1 page drawing

Field of application of the invention

With the help of the control of the stepper motor moving positioning system, the invention makes it possible to realize positioning tasks with only little switching outlay.

The technical parameters are suitable for many applications in robotics and micropositioning.

Characteristic of the known state of the art

For positioning, especially with the help of stepper motors, there are numerous solutions.

Most of these use auxiliaries such as moving pulleys (JP 62-82408 [G05D3 / 00]) or markers of different lengths (JP 57-193994 [H02P8 / 00]) for position control. Others use a comprehensive logic as in DD 259696 and DD212341 (G 05D3 / 00) or the position control is performed permanently by a computer. The economic and tecnnische effort is high and the temporal availability of the control computer limited. The measured values are obtained in the cases described by analog-digital conversion, the analog signals supplied by the sensors. This means an additional hardware effort.

A comparison of position coordinates in software or hardware is u. a. in US 4707 & d9 ((j05B 19/40), however, it is always a matter of comparing digital signals.

Object of the invention

Zi3l the invention is to be positioned with minimal technical effort by step motor synchronous evaluation of Ausg.jngssignals a position sensor. The positioning can be done with and without computer monitoring and ift so compared to known solutions economically favorable universally applicable.

Explanation of the essence of the invention

The invention was based on the object with minimal technical effort by evaluating the output signal of a position sensor to position it above a mark.

According to the invention, the output signal of the position sensor enters the first part of the control circuit, which consists of two serially arranged sample and hold stages. The output signals are linked in a subsequently connected subtracter. This provides the input signal for a trigger whose trigger threshold is adjustable. The output signal of the trigger is logically linked in a gate circuit with an external START signal. This controls a switch which passes the external clock in response to Schaltzusland to a clock control and the stepper motor. The clock control is used for the in-phase control of the sample and hold stages.

embodiment

The invention will be explained using an exemplary embodiment. The drawing shows the block diagram of the control circuit according to the invention.

Its first stage consists of two serially arranged sample and hold stages 2, 3, which serve for the analog storage of the (n) th and (n-1) th measured values from the position sensor 1.

With the first half-cycle of the generator 7 via the clock control 8 to the first sample and hold stage approaching stepping motor clock the current value is taken from the position sensor 1 in the first sample and hold stage 2. With

the second half-clock, which only passes to the second SampL and hold stage 3 via the clock control 8, this value is taken over into the second stage. Each additional full clock, which corresponds to one step of the stepping motor, results in the first sample and hold stage 2 being the (n) th measured value and in the second one being the (n-1) th.

Subsequent to a subtractor 4 results in an input signal for the trigger 5, which corresponds to the difference between two measured values. If the signal exceeds the pre-selectable trigger threshold, the trigger switches and the blocking operation of the transistor T1 acting as a switch stops the positioning process and the stepping motor 9 is stopped. The positioning is complete.

After any necessary change in the trigger threshold to detect another positioning mark, which can be done depending on the application of the circuit r, anuell or computer controlled, the sample and hold stages 2 and 3 can be reinitialized by the signal START and by releasing the acting as a switch transistor T1 be restarted via the gate 6 of the positioning sequence.

With the control circuit according to the invention, the trigger threshold can be positioned over any structures by suitable selection, insofar as the discrete-time sampling of the analog signal delivered by the sensor still has significant changes.

Claims (2)

2S2 claims: 1. Control circuit for a stepper motor moving positioning system with position sensor, characterized in that the output signal of the position sensor enters a first part of the control circuit, which consists of two serially arranged sample and hold stages, wherein the output signals of both sample and hold stages in a subsequently connected subtractor which provides the input signal for a trigger whose trigger threshold is adjustable and whose output signal is logically linked in a gate circuit with the external START signal, wherein the output signal of the gate circuit controls a switch, which depending on the switching state an external clock to a Stepper motor and a clock control switches through and the clock control is used for the in-phase control of the sample and hold stages. 2. A circuit according to claim 1, characterized in that manually or via an external control is adjustable.