DD292093A5 - METHOD AND CIRCUIT FOR AUTOMATIC OAKING OF AN INCREMENTAL POSITIONING SYSTEM - Google Patents

Abstract

The invention relates to a method and a circuit arrangement for automatically calibrating an incremental positioning system with accuracies in the micrometre range, in which the drive for oaking initially runs in the direction of the reference point and provides a pulse for each returned path increment, the response range of the sensor within which the reference point lies. is traversed, within this response range, the pulses supplied by the drive are counted and after driving through the drive is stopped, then ziert the counted pulses at an even number of pulses in half or at an odd number of pulses before halving a pulse are subtracted and the drive is is started in the opposite direction, whereupon the halved number of pulses is decremented from reaching the response range until the value of the number of pulses is zero, whereby the number belonging to the positioning system counter to its beginning swert set and the drive is stopped. A circuit arrangement for carrying out the method is specified. FIG {procedures; Circuitry; incremental positioning system; oaks; Drive; Wegeinkrement; pulses; Sensor, response range; Reference point}

Description

For this 1 page drawing

Field of application of the invention

The invention relates to a method and a circuit arrangement for automatically calibrating an incremental positioning system with accuracies in the micrometer range.

Characteristic of the known state of the art

Each incremental positioning system has, at a given mechanical setting - the reference point - a means to bring as close as possible to the reference point a counter which detects the distance or angular increments that the positioning system travels from that point to the initial position.

With each path or angular increment traveled, an electrical pulse or a constant number of electrical pulses are counted into a counter so that the counter contents represent the location of the part to be moved. Fine Precondition for the accuracy of the positioning system is an exact oak, i. establishing the exact match between the mechanical location "datum point" and the electrical datum point represented by a fixed counter content

These are z. As mechanical arrangements that actuate an electrical contact used. Thus, it is known according to EP 279886 that a Meßdorri is used with a predetermined diameter in a holder and at a predetermined distance from the actual zero point on a Kcvdinatentisch two each having an active sensor surface on the output side connected to an electronic evaluation unit sensors are arranged, said Mandrel and / or the coordinate table relative to each other until the edge of the mandrel activates both sensors and the stored zero set point is corrected. The shortcomings of electronic switching contacts and the wear of the mechanical parts is particularly disadvantageous.

From the usual practice, an arrangement is known for resetting the counter at the reference point using a thermowell contact, which is switched by approaching a permanent magnet when a certain position of the drive is reached. The disadvantage here is the inadequate for high demands accuracy and the dependence on ambient temperature and aging.

In the known methods, the response of a sensor is used as a criterion for a defined position of the positioning system. I ϊ has the disadvantage that its Ansprechschwellü is affected by aging, temperature and / or voltage dependence of the sensor and accuracies in the micrometer range are therefore not achievable.

Object of the invention

The aim of the invention is to provide a method and a circuit arrangement for the precise automatic calibration of an incremental positioning system with little technical effort and low costs.

Explanation of the essence of the invention

The invention has for its object to provide a method and a circuit arrangement for automatically calibrating an incremental positioning with an accuracy of a few micrometers, in the aging of the sensor, temperature changes and / or fluctuations in the operating voltage have no effect on the accuracy of the calibration.

In a method for automatically calibrating an incremental positioning system, in which the drive for calibrating initially runs in the direction of the reference point and returns each Weginkrement distance, the object is achieved in that the response range of the sensor is traversed, within which the reference point is located within this response range, the pulses supplied by the drive are counted and after driving through the drive is stopped, that then halved the counted pulses at an even pulse number or at an odd number of pulses before halving a pulse subtracted and the drive in the opposite direction is started, whereupon the halved pulse count is decremented from reaching the response range of the sensor until the number of pulses is zero, whereby the positioning system belonging to the counter set to its initial value and the drive gest becomes oppt.

A circuit arrangement for carrying out the method for automatically calibrating an incremental positioning at a reference point with a pulse supplying drive and a sensor according to the invention is realized in that the input of the circuit is connected to a clock input of a counter and to a first input of a gate and that on Output of the sensor is a second input of the gate, an enable input of the counter and an input of a monoflop is connected, eir third input of the gate with an output flip-flops and an output of the gate with a clock input of a backward counter and an output of the monoflop with a clock input of the Flip-flops with a charging input of the backward counter and with a first output of the circuit arrangement is connected and that at a carry output of the backward counter, a reset input of the flip-flop and a second output of the circuit arrangement and a Rüc ksetzeingang the counter is connected and that parallel outputs (Ai ... A _n ) of the counter with parallel inputs (E ₀ ... E _n - ι) of the backward counter are connected.

embodiment

A circuit arrangement for carrying out the method according to the invention will be explained in more detail below using an exemplary embodiment.

The accompanying drawing shows a block diagram of the circuit arrangement according to the invention. An input 1 of the circuit arrangement is connected to a clock input 2 of a counter 3 and to a first characteristic 4 of a gate 5. At an output 6 of a sensor 7 iii a second input 8 of the gate 5, an enable input 9 of the counter 3 and an input 10 of a monoflop 11 connected. A third input 12 of the gate 5 is connected to an output 13 of a flip-flop 14. An output 15 of the gate 5 is connected to a clock input 16 of a backward counter 17. An output 18 of the monoflop 11 is connected to a clock input 19 of the flip-flop 14, to a charging input 20 of the backward counter 17 and to a first output 21 of the circuit arrangement. At a carry output 22 of the backward counter 17, a reset input 23 of the flip-flop 14, a second output 24 of the circuit arrangement and a reset input 25 of the counter 3 is connected. Parallel outputs A ₁ , A ₂ ... A _{n of} the counter 3 are connected to parallel inputs E ₀ , E ₁ ... E _n _, the backward counter 17.

On command for calibrating the positioning system, not shown, the drive is in the direction of reference point in motion and supplies in a known manner per zurückiminem Weginkrement a pulse to the positioning system not shown counter and also to the input 1 of the circuit. Shortly before reaching the reference point, the sensor 7 responds and gives from its output 6 oin signal to the enable input 9 of the counter 3, so that the arriving via the input 1 of the circuit to the input 2 of the counter 3 pulses are counted. As soon as the drive has passed through the response range of the sensor 7 and leaves it again, a signal change occurs at the output 6 of the sensor 7. As a result, by blocking the release input 9 of the counter 3, a further pulse input into the counter 3 is prevented and, on the other hand, the edge-triggered monoflop 11 is caused to emit a pulse at its output 18. This pulse causes via a connected to the first output 21 of the circuit arrangement, not shown circuit that the drive is stopped and restarted after a delay in the opposite direction, that the flip-flop 14 is set via the clock input 19, and that the down counter 17th caused by the pulse at its charging input 20 - the at its inputs E ₀ ... E _n . _t applied signals, due to the new direction of movement of the drive returns to the response range of the sensor 7 and its output 6 again supplies high potential, so that the input 1 of the circuit coming from the positioning pulses can pass the gate 5 and the content of the Back counter 17 is decripts. If the content of the backward counter 17 is zero, its carry output 22 provides a pulse which resets the counter 3 and the flip-flop 14, whereby gate 5 blocks and thus no further pulses can enter the down counter 17 and the connected to the second output 24 of the circuit to the positioning system not shown counter sets to its initial value and the drive turns off.

Claims (2)

Anspruch [en] A method of automatically calibrating an incremental positioning system, wherein the drive for calibrating is initially in the direction of the reference point and provides return travel per path increment, characterized in that the response range of the sensor is traversed, within which the reference point is located within This response range is counted the pulses supplied by the drive and after passing through the drive is stopped, that then halved the counted pulses at an even number of pulses or subtracted at an odd number of pulses before halving a pulse and the drive is started in the opposite direction, whereupon the halved pulse count is decremented from reaching the sensor's response range until the number of pulses is zero, whereby the counter associated with the positioning system is reset to its initial value and the drive is stopped. 2. A circuit arrangement for automatically calibrating an incremental positioning system at a reference point with a pulse-supplying drive and a sensor, characterized in that the input (1) of the circuit arrangement with a clock input (2) of a counter (3) and with a first input (4 ) of a gate (5) and that at the output (6) of the sensor (7) has a second input (8) of the gate (5), an enable input (9) of the counter (3) and an input (10) of a monoflop (11) Jangeschlossen is, wherein a third input (12) of the gate (5) with an output (13) of a flip-flop (14) and an output (15) of the gate (5) with a clock input (16) of a backward counter (17) and an output (18) of the monoflop (11) is connected to a clock input (19) of the flip-flop (14), to a charging input (20) of the backward counter (17) and to a first output (21) of the circuit Carry out (22) of the backward counter (17) ei n reset input (23) of the flip-flop (14) and a second output (24) of the circuit arrangement and a reset input (25) of the counter (3) is connected and that parallel outputs (A ₁ ... A _n ) of the counter (3) with parallel inputs (E ₀ ... E _n _,) of the backward counter (17) are connected.