DE2232157C3 - Device for suppressing undesired follow-up control signals, the formation of which has an impact in the sense of control oscillations, for the relative deviations caused by the running time between a default arrangement and a follow-up system in a control loop - Google Patents

Description

The invention relates to a device for suppressing undesired tracking control signals, the formation of which has effects in the sense of Has control oscillations for the relative deviations due to the running time between a movable default arrangement and one with a follow-up system coupled detector in a device for converting motion sequences into electrical ones Signals simultaneously during the movement sequences, in the case of the actuators a lagging of the in the influence of the Initiate default arrangement located directional detector.

The tracked in the area of influence of the default arrangement in the plan level of a coordinate recorder Detector forms its measurement signals as a function of the deviation of the relative position of the default arrangement with respect to the detector. Will the Moving the default arrangement in the plane plane, the detector generates signals that, after processing, the Actuators cause the detector to track the movements of the default arrangement.

During this detector after-run, which is largely due to the mechanics of the actuators certain delay occurs, the default Order have been moved on. The detector is running thus to a certain extent behind the default arrangement with a certain delay.

In one from the magazine "Werkstatt-Technik - Zeitschrift für industrial Produktion" 61 (1971), No. 2,

P. 78 and 79, the machine tool control that has become known, interventions in the In the form of an analog control with a continuous comparison of the actual value and the actual value and feedback of the measured and evaluated errors thereby bringing about an accuracy control when copying workpieces.

The invention is based on the object of providing undesired tracking control signals for the relative deviations between a movable one due to the running time Default arrangement and a detector coupled to a tracking system and thus the on such Follow-up control signals attributable tendency to control oscillations ces follow-up system with a Device of the type mentioned to suppress ken.

Without these unwanted follow-up control signals being suppressed, provided that that the follow-up control works quickly with respect to the system-related follow-up delay, which in the With regard to a meaningful input speed, it is desirable that other undesired follow-up control signals are also generated when if the tracking control signals required for the detector tracking have already been generated, themselves however, due to the running time r, och ,, ir'nt affected to have. However, control signals are thus generated for an excessively large overtravel, as a result of which the detector to be tracked runs beyond the setpoint position. as The following will now be followed by others in the opposite direction controlling tracking signals are generated, which in turn are in in the same way cause the formation of undesired follow-up control signals. This process leads to The follow-up system tends to oscillate and thus makes it unstable. Suppression of the undesirable

Follow-up control signals are intended to eliminate this deficiency.

The object is achieved according to the invention in that for both ordinate controls separately in Compensation generators each have an electrical compensation signal with one of the mechanical running times corresponding duration is always formed if the previously compensated, if necessary, by one each Amplifier and threshold levels connected to it, derived control signal for the respectively assigned actuating drive has assumed a value at which the actuator is to come into operation, and that this newly obtained compensation signal is added up to any old compensation signals that may still be present, with these compensation signals weakening the respectively assigned trigger th measurement signals during their processing and / or a reduction in their evaluation.

Since an immediate after-run of the detector leads to an immediate reduction in the distance between

the detector and the default arrangement and thus to a simultaneous reduction of the measurement signal amplitude would lead, the compensation signals must carry out this process, for example by weakening the measurement signal amplitude to recreate. In this case, the follow-up system inevitably becomes less sensitive during the compensation.

This effect can reduce the follow-up speed of the detector when it is tracking from a greater distance. Such a case is present, for example, when the default arrangement is to The beginning of an input is brought into a starting position in which the detector is larger Distance must first run in. Here, the compensation signals can increase the evaluation sensitivity for the measurement signals, which are already weak in the far field, decrease so much that the tracking control always then suspends when a compensation signal is present. the The consequence is an undesirable reduction in the tracking speed of the detector from a greater distance.

To prevent slowing down of the trailing detector from larger Distance are the KompensationssignaJ-Erkeuger also used in the relative position of the default arrangement with respect to the detector between Differentiate near field and far field and switch off the compensation process in the far field. The one for that The field weakening existing far field can be measured in the detector, whereby the field strength present in each case characterizing measurement signals can be fed to a threshold level after their processing, which when undershooted of a reference value emits a digital signal which characterizes the far field and which the Compensation control switches off

On the basis of an exemplary embodiment, the invention is illustrated in the drawing and in the following explained; shows in the drawing

F i g. 1 shows a basic circuit diagram of the circuit arrangement F i g. 2 details of the circuit diagram according to FIG. 1.

The Ausfühi ungsbeispiel is at a facility for Conversion of handwritten records into electrical signals explains the principle mode of operation the underlying device is initially based on the F i g. 1 described.

The write information is a default configuration in the shape of a pen 1 by the operator on a not shown in the drawing pad recorded The pen 1 includes a permanent magnetic field source whose position relative to a movable in the x and y direction detector 2 of two at detector 2 crosswise field plate pairs 3 (x-ordinate) and 4 (y-ordinate) determined by its own for each ordinate difference value measurement is the difference value measuring signals marked with its sign, the direction and amplitude, the magnitude of the relative displacement of the detector 2 relative on pen 1 for the respective m-ordered ordinate.

The differential value measurement signals are each supplied by a DC amplifier 5 (jr ordinate) and 6 (^ ordinate) amplified and separated by sign to a pair of threshold levels 7 (x-ordinate) and 8 (y-ordinate) decoupled The threshold levels are designed with respect to their sensitivity so that they only then respond to a signal when the Signal amplitude corresponding deviation between

ίο the pen 1 and the detector 2 a Required minimum size exceeds the output signals of threshold level pairs 7 (jc ordinate) and 8 (y-ordinate) are then each via a clock pulse switch pair 9 (jf-ordinate) and 10 (y-ordinate) guided in which they use the clock signals of the clock generator 13 in corresponding step signals for the control of the stepper motors 11 (x-ordinate) and 12 (y-ordinate) can be converted. The assignment the respective motor direction of rotation is selected so that the detector 2 is the movements of the Pen 1 follows

In the present exemplary embodiment, the maximum step frequency 300 steps per second for each drive. The running time to be compensated should amount to 5 ms per actuator. This results in a duration for each compensation signal of as well 5 ms. Consequently, while a compensation signal is present, the triggering step can be followed by another Follow motor step. This must also trigger a compensation signal lasting 5 ms, εο that im In the present case, the compensation signal generator is to be designed in two stages for each system of ordinates

Fig. 2 shows the block diagram of such a Compensation signal generator for an ordinate system. An "OR" gate 16 captures the pace control signals for the right and left rotation of the motor together.

The output signals of the gate 16 is set with its leading edge of a monostable multivibrator 17 whose Kippdauer is 23 ms, the output signals of the monostable multivibrator 17 in turn set 24 ms late · with their end edge of a further monostable multivibrator 18 whose Kippdauer is also 2J5 ms the toggle signals of the stages 17 and 18 are then combined via a network 19 to form the continuous compensation signal. This compensation signal can thus have one or two amplitude levels, depending on whether only one or both monostable multivibrators have been set

In Fig. 1 shows two such compensation signal generators 14 (x-ordinate) and 15 (y-ordinate) their output signals to the assigned threshold level pairs 7 (Jt ordinate) and 8 (^ ordinate) »Elt igjn where they are the responsiveness of the

individual threshold levels depending on their reduce the respective amplitude value in two degrees and thus immediate detector tracking simulate electrically.

For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1. Device for suppressing undesired tracking control signals, their formation Has effects in the sense of control oscillations for the relative deviations due to the running time between a movable default arrangement and one coupled to a tracking system Detector in a device for converting motion sequences into electrical signals simultaneously During the movement sequences, in the case of the actuators, the direction-sensitive detector, which is under the influence of the specification arrangement, continues to run cause, characterized in that for both ordinate controls, separately in compensation signal generators (14, 15), an electrical compensation signal with a duration corresponding to the mechanical running time is always then is formed, if the previously compensated, if necessary, by an amplifier (5, 6) and Schwellwcrtstufen (7, 8) connected to it, the control signal for the respectively assigned actuator (11, 12) assumes a value has, in which the actuator is to come into operation, and that this newly obtained compensation signal may possibly still be present old Compensation signals is added up, these compensation signals a weakening of the measurement signals assigned to them in their processing and / or a reduction in their Evaluation from '^ sen. 2. Apparatus according to claim!, Characterized in that to prevent a reduction in speed of the trailing detector (2) from a greater distance, the co-compensation signal generator (14, 15) are also used, which in the relative position of the default arrangement (1) with respect to the detector (2) between the near field and Distinguish far field and switch off the compensation process in the far field. 3. Apparatus according to claim 2, characterized in that the existing for the far field The field weakening at the detector (2) can be measured and the field strength characterizing the respective field strength Measurement signals can be fed to the associated threshold value stage (7 or 8) after their processing, which if the value falls below a reference value, emits a digital signal which characterizes the far field and which switches off the compensation process.