DD237131B1 - CIRCUIT ARRANGEMENT FOR MEASURING POINTS IN THREE LEVELS - Google Patents

Description

Program change could be realized to execute immediately. A more effective design of the measuring process increases the availability of the machine for processing the workpieces.

According to the invention, this object is achieved in that a switch signal line on the first input of the control unit upstream impulse former is performed at the second input a first with a line from the clock conjunctively linked call line from the first output of a i'am control unit coupled evaluator arrives. The evaluator is followed by a correction logic and a measured value data memory via a switch. The measured value data memory is connected to the parameter calculation unit and the correction logic is connected to the central control and calculating unit.

embodiment

The figure shows the circuit arrangement according to the invention.

A program memory 1, in which the required measuring operations are stored, a call and input unit 2, a control unit 3, a central control and calculating unit 5, a control unit 6 and coupled to the drives positioning and Meßwerterfassungseinrichtungen 8,9 connected in series. Between the call and input unit 2 and the central control and calculating unit 5, a data memory 4 is arranged, which is connected to a arranged after the control unit 3 parameter calculation unit 10. The control unit β is directly coupled to an evaluator 7, which is connected via a switch 13 with a correction logic 12 and a measured value data memory 11 upstream of the parameter calculation unit 10. The probe 14 is connected via a switching signal line SS to the first input of a pulse shaper 15 which is connected to the control unit 6. From the evaluator 7 is a first call line AL1 conjunctively linked to a line from the clock 17 to the second input of the pulse shaper 15 out. About second and third call lines AL 2, AL 3 is the evaluator with the central control and arithmetic unit 5, the call and input unit 2 and conjunctively connected to an output line of the control unit 3 connected to the parameter calculation unit 10. The operation of the circuit arrangement is as follows:

For processing a normal processing step, the corresponding program sentence is read from the program memory 1 by the call and input unit 2. Data memory 4 and control unit 3 are activated and the sentence is forwarded to the central control and calculating unit 5, where it is completed with the retrieved data from the data memory 4. The resulting setpoints are forwarded via the control unit 6 to the positioning device 8. The actual values of the respective position determined by the measured value detection device 9 are sent as feedback to the control unit 6. Here, the comparison of setpoint and actual value and the evaluation with regard to the positioning process takes place. If the difference between setpoint and actual value is not equal to zero, positioning is continued. A stop condition results from the zero difference between setpoint and actual value, the point to be positioned has been reached. If the stop signal is formed by the evaluator 7 is a forwarding as a call signal AL2 for the next processing sentence to the central control and arithmetic unit 5 and the call and input unit 2. Thus, the subsequent program sentence is called and a new positioning begins. The evaluator 7 has the task to evaluate the corresponding signals and to take over the control sequence or the block forwarding only when calling "Measure." Otherwise, calls for the record forwarding in the evaluator 7 are switched through

 When calling "Measure", the circuit arrangement works as follows:

The control unit 6 for the Meßwerterfassungs- and positioning 8.9 controls the data exchange, triggered by the clock 17 and in conjunction with the evaluator 7, in a certain time frame. If, due to the workpiece program, the call "Measure" is applied to the evaluator 7 via the central control and calculating unit 5, the evaluator 7 is activated and a call signal is formed.

Thus, with this call signal via the call line AL1, which is conjunctively linked to the signal of the clock 17 via the gate 18, the pulse generator 15 is activated. By switching the probe 14 (LOW / HIGH signal or HIGH / LOW signal) when placed on the workpiece or during removal, the switching signal SS is generated by the probe 14, which passes to the pulse shaper 15. In the pulse shaper 15, a switching edge is formed. The pulse shaper causes the switching signal of the probe for opening and closing in the same form to the control unit 6 and the evaluator 7 is performed both when starting and when retracting from the workpiece edge. This makes it possible to measure in both traversing directions. The switching signal of the probe 14 causes in the control unit 6 and the evaluator 7, that at the moment of switching the recorded from the Meßwerterfassungseinrichtung 9 instantaneous actual value (equal to measured value) is taken over the switch 13 in the measured value data memory 11. This measured value is the absolute actual position of all axes to be positioned. In the measured value data memory 11, the measured value for the parameter calculation unit 10 is ready. The parameter calculation unit 10 is called via the call line AL3 from the control unit 6 with the appropriate part program. Due to the direct connection of the measured value data memory 11 to the parameter calculation unit 10, the measured values are included directly in the parameter calculation or taken over into any parameters and are thereby included in the parameter functions of the control. This is a flexible targeted processing, z. B. for arithmetic functions, without additional evaluation and arithmetic units, possible. The result is stored in the data memory 4 and is immediately available to the process again.

Furthermore, it is caused by the switching signal of the probe 14 that the current positioning, although the difference between the target position and actual position is not equal to zero, is stopped immediately because the evaluator 7 and the control unit 6, a stop signal is formed, which reaches the positioning device 7 , This axis movement is stopped regardless of the specification in the workpiece program.

After the axis standstill of the positioning device 8, when the follower path is equal to zero, the instantaneous recorded by the Meßwerterfassungseinrichtung 9 actual positions are written by the evaluator 7 via the switch 13 in the correction logic 12 and from there as new setpoints to the central control and arithmetic unit fifth directed. There is a

Immediate correction of the soil position, which was not achieved by switching the probe and the resulting Anhal'-зп. The central control and calculating unit 5 is set by this correction (target position is equal Istpusition) for the next positioning in the correct starting position, without having to then approach an absolute position, since the Wegbilanz in the numerical control is now balanced. It is achieved that the machining can be continued immediately at the point at which the axes have come to a standstill, also a new measuring process can be connected immediately. A retraction movement is not required.

With entspreci onder design of the measuring programs, it is possible to search with the controller a contour at high speed and anschlie c. to measure exactly. In addition, memory locations in the program memory 1 are still saved.

Claims (1)

Circuit arrangement for dimensional recording of points in three levels by means of the switching signal of a measuring device, in particular a probe, using functional units belonging to a numerical control, such as program and data memory, call, input, control and parameter calculation units, clock, central control and Calculating unit, control unit with downstream positioning and measured value detection devices, which are coupled to drives, characterized in that of the probe (14) a switching signal line (SS) on the first input of the control unit (6) upstream Impulsformers (15) is guided the second input of which a first line of the clock (17) conjunctively linked call line (AL 1) from the first output of the control unit (6) coupled evaluator (7) that the evaluator (7) via a switch (13) a correction logic (12) and a measured value data memory (11) are connected downstream of the Meßwer Data memory (11) with the parameter computing unit (10) is connected, and that the correction logic (12) to the central control and calculating unit (5) is connected. For this 1 page drawing Field of application of the invention The invention relates to the three-level recording of points and their controlled flexible processing in the field of digital control engineering. The solution enables the measurement detection of different points on bodies, e.g. Workpieces, their simple process-dependent billing and thus a process-dependent control, the measurement can take place before and / or between the individual processing phases. Characteristic of the known technical solutions Known is a method for the dimensional recording of points on workpieces, in which measured in the machine and the result is used to control the machine ("Measuring in the CNC machine" magazine "tzfür Metallbearbeitung", 76th year, 1982, Issue 07 / 82, pages 30-32). The machine tool itself is used as a measuring machine and the measurement results are evaluated for the further course of processing. A precision probe is used which, after being touched by the workpiece, supplies a signal to the controller, which then transmits the position actual value to a memory. By subtracting the position reference value, the correction is calculated, which is added to the tool offset. What is needed is a switching probe, which is used instead of the tool. In this solution, it is possible to measure only in the direction of "contact", which means that after the measuring process a retraction to the starting point takes place towards a fixed position.For the practical application, it is disadvantageous that a measurement usually consists of several measuring operations With the starting point gradually approaching the contour, the speed must be reduced to gradually increase the accuracy of the measured value.The retraction evaluation to the starting point after each measurement (at contact or not) takes unnecessarily much time and there It is disadvantageous that not the point at which the machine axes come to a standstill after the first measuring operation, as a starting point for further processing or for a further measuring operation serves. A further disadvantage is that only when touching the DUT by measuring probe ("contact") can be measured, but not when leaving. Object of the invention The aim of the invention is to connect existing functional units of a numerical control with little circuit complexity so or perfect by other units such that by means of the functional enhancement achieved by a comprehensive automation and a more effective design of the measuring process is achieved. Explanation of the essence of the invention The object of the invention is to provide a circuit arrangement for dimensional recording of ι in three levels levels by means of the switching signal of a measuring device, in particular a probe, using a numerical control belonging functional units, such as program and data memory, call and input unit, control unit, central control - and arithmetic unit, clock, control unit with downstream positioning and Meßwerterfassungseinrichtungen, which are coupled to the drives, the call and the direct query of Meßtasterschaltsignals done in the keyed system, the detected measuring points are quickly offset depending on the process and the entire controller in the situation to respond better and more comprehensively to the process to be controlled. A workpiece contour can be searched with high accuracy and then measured accurately. It is possible to make corrections that would otherwise only have one