Dr. Johannes Heidenhain Gmbh

Johannes Heidenhain Gmbh

Ernst Schwefel

Alfons Baumgartner

Dieter Michel

Horst Burkhardt

Michael Rauth

Olivier Pariaux

Martin Huber

Anton Mayer

Alois Zimmermann

An interferometric type photoelectric measuring device is disclosed. The photoelectric angle measuring device includes a graduation carrier having a circular graduation and a scanning arrangement for the diametral scanning of the circular graduation. The scanning arrangement is constructed as an integrated optical circuit.

Angle measuring arrangement

A process and apparatus for improving the resolution of square, subdivided signals by synchronizing the signals with an auxiliary clock signal. The signals are further conditioned by switching logic elements which, in dependence upon adjacent signals in the subdivision order and upon the auxiliary clock signal, only allow the states of the signals to change at predefined times.

Process and apparatus for the synchronization of square signals

A method for restarting a tool on a workpiece contour in a numerically controlled processing machine of the type having a display unit for alphanumerical and/or graphical representation of processing information. After a program interruption, the program is executed anew in a control mode without machine movement from a predetermined starting point, and the resulting workpiece contour is continuously, graphically represented on the display unit. The operator utilizes this graphic display to determine an end point of the control mode program execution. The machine is then transferred into its axial positions and its function state to the program state of the end point, and the processing program with machine movements is continued from this end point, thereby starting the tool onto the desired tool path.

Method for restarting a tool onto a workpiece contour

A control system for a processing machine such as an eroding machine operates to determine preferred withdrawal directions between a workpiece and a tool. In addition to the path movements necessary for the treatment process, the control system determines in advance at each point along the predetermined path a withdrawal direction oriented away from the surface being processed. This withdrawal direction runs essentially normal or perpendicular to the surface being processed on the workpiece. The amount of the desired separation between the tool and the workpiece along the withdrawal path is applied as an input to the control system in accordance with predetermined parameters of the treatment process.

Numerical control system for determining tool withdrawal direction

A control device for a numerically controlled machine tool includes both on/off and continuously variable switches which are coupled via a computer to associated machine functions such as coolant flow or feed rate. The computer is programmed to operate in any one of three modes. In the first mode the manually controlled input switches are read by the computer during computer-controlled processing of a first workpiece according to processing information stored in memory, the computer stores information regarding the state of the switches for later use, and also controls the machine functions to correspond with the current state of the input switches. In the second mode the computer controls the machine functions during computer-controlled processing of subsequent workpieces in accordance with previously stored information, independently of the current position of the input switches. In the third mode, the computer controls the associated machine functions during computer-controlled processing of a workpiece in accordance with the current state of the input switches, without storing this information. In use, this control device allows an operator to program associated machine tool functions at the selected times in the computer-controlled processing of a workpiece by operating the same switches which are customarily used to select additional machine functions, and thereby eliminate arbitrary programming codes and procedures that require programming skills.

Numerical control device

A freely programmable control system is disclosed which includes a computer, a data memory, and a program memory, as well as a program controllable logical network for individual bit processing and an individual bit memory. The disclosed control system operates as an integrated system which utilizes both commands for the computer and separate commands for individual bit processing. Both types of commands are stored in the program memory as an integrated program. During individual bit processing the commands for the individual bit operations are routed from the program memory to the logical network circuit for individual bit processing, and are there executed. Similarly, during computer processing the commands for the computer are transferred directly to the computer and are there executed. The commands for the individual bit processing are kept away from the computer by a switching circuit which operates to supply the computer with a command to increment the computer program counter for each individual bit instruction.

Integrated bit processor/word processor control system

An improved method of interval interpolation, i.e., subdivision of a signal period, is disclosed. Generally, at least one scanning signal (S.sub.1, S.sub.2) generated by a scanning unit (G) scanning a scale (M) is converted into digital form and input to a computer (R) for the computation of interpolation values. In the case of a high subdivision factor, before the execution of the interpolation algorithm, the scanning signals input to the computer (R) are corrected for amplitude inequality, incorrect phase differential and the direct voltage component of the scanning signals (S.sub.1, S.sub.2). The correction values are automatically determined by direct voltage detectors (GT.sub.1, GT.sub.2), amplitude detectors (AT.sub.1, AT.sub.2) and a phase comparator (PV) during at least one pass of the measuring system (G, M) over its measuring interval. The correction values are stored in the computer (R) and are automatically utilized thereby in interpolation during measurement.

Method of interval interpolation

A digital electrical length or angle-measuring device connects digitalized scanning signals of at least one coarser revolution code group to first addressing inputs of one or more fixed value stores containing binary-stored calculated variants of the digitalized signals in form of tables, and the variants are alternately connected to outputs of the store in dependence upon the logical condition of the control signal which is derived from the respective higher resolution code groups and which is connected to a second addressing input of the store.

Digital electrical length or angle measuring device

In a numerically controlled machine tool including a scale, a scanning unit, and a programmable controller a switch is provided to designate the tool correction to be applied to compensate for variations in tool dimensions. This switch has a first position, in which the controller is directed to lengthen the tool path length by an amount corresponding to the tool correction, a second position, in which the controller is directed to shorten the tool path length by an amount corresponding to the tool correction, and a third position, in which the controller is directed to apply no tool corrections to the tool path length.

Correction selection device

An apparatus is disclosed for processing the output of an incremental measuring device of the type which provides a periodic analog output signal. The analog output signal is applied to a trigger circuit to produce a square wave signal which is applied as an input to an updown counter. This counter operates to count the number of complete cycles of the analog signal associated with the measurement. The analog signal is also applied to a circuit which acts to generate a coded intermediate value in response to the sign and amplitude of the analog signal. The counter value and the coded intermediate value are both applied as inputs to a computer which combines these two values to produce a composite reading in which the coded intermediate value supplies the high precision component of the reading and the counter value supplies the low precision component. In this way increased precision readings can be attained without increasing the maximum counting rate of the counter.

Interpolation utilization apparatus

An improved counter for use with an incremental measuring device is disclosed which includes an up-down counter, a plurality of memory units, a computer, and means for designating any of the memory units. The computer is coupled to the counter and the memory units and is programmed to algebraically combine the value stored in the counter with the value stored in the designated memory unit to generate an output value for display. In the preferred embodiment, circuits are provided for setting the individual memory units to preselected values. The counter of this invention can be used to selectively display the measured position in any one of several measurement modes by designation of the appropriate memory unit.

Electronic counter for incremental measuring device

An interpolation process is described for use with an incremental position measuring device which produces a periodic analog output signal. The output signal is digitized and then applied as an input to a digital computer programmed to calculate the interpolation value of the signal. In the preferred embodiment the computer is also programmed to apply a number of corrections to the digitized signal prior to interpolation.

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Traunreut, Germany

Ernst Schwefel