DE1588925A1 - Numerical route control system - Google Patents

Description

Numerical Route Control System The invention relates to a numerical Position control system, in particular for machine tools, with an operation counter to the. serial information processing and an internal computer, whereby the Numbers that represent position values and pre-switch-off values are stored and the Internal computer supplied with equivalent digits of two numbers and after clearing be forwarded to a computing device, and the carry output from the highest digit for the direction decision a direction memory and the potential change of the carry output is fed to an output unit, at the outputs of which the Relays for the speed levels of the drive are connected.

They are route control systems with absolutely digital information processing known. These systems are known to offer the highest level of reliability since they are less sensitive to glitches. The disadvantage lies in the proportion high expenditure on logical components, the expenditure increases even more if these control systems with some additional devices, such as coordinate transformationg zero-point transformation, Cutter diameter correction, several pre-switch-off points, etc. can be equipped should. Position control systems of this type use computing circuits to offset the position values. The direction is derived from the sign of the calculation result, where the size of the numerical value of the calculation result for the pre-shutdown or final shutdown is used. These controls are great because of the computers they contain expensive, This is why these computers were designed as serial computers, in order to reduce the circuit complexity within the computing circuit. Still are these circuits are still very extensive, because they consist of two values to be calculated each the subtotal is formed, which must then be cached in order to obtain it to be charged with the next value.

Positioning controls are also known which use comparator circuits without the comparison result being output numerically. The carry output from the highest comparator point is also used here for the direction decision. The change in potential of the carry output is used as the point of coincidence of the two compared values for controlling the positioning drive. This control is very simple in structure and the cost of switching elements is minimal. This control can be used advantageously for simple positioning in which only the sign of the difference and the coincidence between setpoint and actual value are to be determined ! -natentransformation (fixed value), a correction value input as well as the programming of pre-switch-off values, this simple positioning control cannot be used. to be set up with minimal effort and high operational reliability.

The invention is based on the object of creating a numerical route control system in which the position values and pre-switch-off values are to be offset without intermediate sums and the output unit, in addition to switching the CD drive stages, takes over the preselection of an assigned pre-switch-off value and the circuit arrangement for controlling one coordinate for several coordinates should be exploitable at the same time.

According to the invention the object is achieved in that the equivalent Digits of all numbers one after the other from an operation counter consisting of two ring counters are fed to the internal computer for billing in such a way that at each output des'ersten ring counter each have a row line and at each output of the second Ring counter is connected to a column line which is in a matrix-like manner Row and column lines connected 9 assigned to the digit memories, Calls-and-elements are routed to the internal computer via OR-elements to lead. The sum runs for so long between the internal computer and the arithmetic memory until the equivalent digits of all numbers have been offset. The one in the settlement Any resulting carry-overs are entered into one of the number to be offset and its line line assigned transfer memory entered and the next higher when offsetting Digit position offset with the outputs of the carry memory on a Input of the internal computer.

The output of the carry memory of the highest row line is switched to one input of an AND element, its further inputs to the last Counting stages of the ring counter and its output to the input of an output unit connected that calls up the corresponding pre-switch-off values and from the carry output the highest digit is advanced.

The column lines are connected to the Digit digits of the numbers of all coordinates connected, with another counter is provided, the outputs of which are the row lines of the numbers of a coordinate connects to the ring counter outputs. Other special designs the solution according to the invention can be found in the subclaims and the description.

A particular advantage of the solution according to the invention is that an arithmetic memory is dispensed with over the entire length of the digits and only one arithmetic memory is used for one digit position. Exemplary embodiments of the invention are shown in the drawings. 1 shows a workpiece to be processed in an XY coordinate system with the entry of the position values, FIG. 2 shows a block diagram of the path control system with control of the direction memory from the output unit, FIG. 3 the same block diagram with control of the direction memory from the transfer output of the actual value FIG. 4 shows a logic circuit diagram of the digits and their control with the tetradic structure of the digits, FIG. 5 shows a switching variant of the tetradic digits with contacts. The position of the workpiece I is specified as the fixed value F (FIG. 1) , with which the nominal value S, the correction value K (cutter radius correction) and the actual value J of the tool II must be offset. Correction value K and setpoint value S can be signed, ie. H. must be added or subtracted. The first necessary arithmetic operation is used to determine the direction in which the positioning drive must be switched on in order to get to the target point. If the computer result is expressed as a difference, the difference will decrease until the positioning drive is switched off at zero incidence because the position has been reached. This zero coincidence point is derived from the change in potential of the carry output from the highest digit (change in sign of the direction output). The calculation result itself is in the calculation memory as a sum and is no longer required at this moment. If you now design the arithmetic process so that the values F, Sq Kg J are not added horizontally, but vertically, that is, all values in one column (digit) are completely calculated and only then go to the next higher column, you can access an arithmetic memory via the forego the entire length of the digits. All that is required is a carry-over memory. This carry memory has m-1 bits if m is the number of values to be calculated. The statement of the direction output is evaluated accordingly by sending a switching signal to an output unit when the potential of the direction output changes.

The output unit controls the drive stages of the positioning drive via relay. At the same time, the outputs of the output unit call a corresponding one Pre-switch-off value.

The outputs of the output unit switch in their order For example, the rapid traverse on the feed drive, the feed drive on creep speed around. The last output then switches off at creep speed, whereby the position is reached is.

The Vorzelclien according to the content of the direction memory. The signs for the target value and the correction value must be programmed. The fixed value F is only positive, the actual value J must always be subtracted.

In Fig. 2, the operation counter, consisting of a ring counter Z 1 and a ring counter Z 2, is shown. The ring counters Z 1 and Z 2 are controlled by a clock center, not shown. Lines 1 to 5 contain the numerical values to be calculated, the fixed value F, the correction value K, the target value S, the pre-switch-off values V and the actual value J. The individual digits of the numerical values to be offset are shown in columns 11 to 14. The design is only shown in this diagram for a better overview. The individual values are stored in completely different ways and are only controlled according to the scheme shown in FIG.

Lines 2 to 5 are each assigned a carry memory U2 to U5. The ring counter Z 1 consists of a number of output stages corresponding to the number of values to be calculated. In the same way, the ring counter Z 2 has a number of output stages corresponding to the number of columns 11 to 14. Each of the symbolically represented digits is connected to an internal computer 21 via an OR element 20. The internal computer 21 is followed by an arithmetic memory 22, the output of which is fed back to the input of the internal computer. The carry output 23 of the internal computer 21 is connected to the carry over memories U2 to U5, the outputs of which are present at a common input 24 of the internal computer 21. The output of the highest carry memory U5 is connected to an AND element 25 , the other inputs of which are connected to the last outputs of the ring counters Z 1 and Z 2. The output of the AND element 25 is applied to the output unit 26 , the first output of which is assigned to a direction memory 27 and its further outputs 28, 299, 309 relays for rapid traverse, feed and creep speed of the positioning drive.

In line 4 there are two pre-switch-off values which are parallel to the carry memory U4 and the output of the ring counter Z1 for calling up line 4. The two advance 'switching values are entered in two lines 4 a and 4 b . Both lines 4 a and 4 b are preceded by an AND element 31 or 32 , to which the output of the ring counter Zl for calling up line 4 is connected. The AND element 31 is connected to the output 28 and the AND element 32 to the output 29 of the output unit 26 .

The internal computer 21 consists in a known manner of the actual Computer as well as an output memory, whereby the output memory also includes the accruing Picks up carries. The internal computer also has a device for Generation of intermediate clocks, which are delivered in dependence on external call impulses and the processes within the internal computer are controlled.

The mode of action 'of the path control system is as follows: From the not shown central clock ring counter Z 1 is driven and switched on in each case the lines 1 to 5 through its output stage to voltage. In the initial state, the ring counter Z 2 is at its first counting level, so that the column 11 is also connected to voltage. When counting from the last to the first counting stage of the ring counter Zl, a counting pulse is given to the ring counter Z 2, so that the digits of one digit position (column 11 to 14) are always called up one after the other and then switched to the next higher digit position by the ring counter Z2 will. This means that one of the symbolically represented number levels is always called up.

For each of these main clocks, in which the ring counters Zl and Z2 call up one of the digits, two sub-clocks A q B are generated in the internal computer, each of these sub-clocks consisting of a delete and a write clock. Starting with the main cycle, the value in the internal computer 21 is deleted by the A delete cycle. The A write clock transfers the values to the computer. There, these are offset and recorded in the output memory of the internal computer. The B delete cycle deletes the downstream arithmetic memory 22 and the corresponding carry memory U2 to U5 and in the B write cycle the calculation result is again given to arithmetic memory 22 and the carry output to the corresponding carry memory U2 to t15. After this sub-cycle has elapsed, the main cycle disappears and the following main cycle takes the next digit into account in the same way.

From this it can be seen that each digit is calculated one after the other in a digit position, with the transfer memory U2 to U5 assigned to the lines being called up by the line line and its values being sent to the internal computer for accounting deleted from the lower cycle of the internal computer and at the next write cycle, the same carry-over memory takes over the carry-over that was newly created in the calculation. This measure makes it possible to manage with one carry-over memory for each numerical value to be calculated. At the end of the calculation of a column (digit), as already mentioned, the next higher digit is called up by advancing the ring counter Z2. With this advancement, the internal computer 21 and the Rec'ins.icicher 22 are deleted at the same time because the calculation result as a sum is of no interest. At the final cycle, ie the last stage of the ring counter Z 1 and the last stage of the ring counter Z2, the AND element 25 becomes continuous and the output of the carry memory U5 reaches the direction memory 27 via the output unit 26. The output unit 26 stands up in its starting point the first counting stage, in which the direction memory 27 is switched on. Simultaneously with the input of the direction signal, the output unit counts one step further and switches the rapid traverse drive stage in its output 28 , so that the positioning drive starts in the correspondingly determined direction. At the same time, the output 28 calls the AND element 31 , so that the pre-switch-off value in line 4a is included in the next calculation sequence. Similarly, the drive stage feeding speed retrieves at the output 29 of the output work 26, the AND gate 32 and switches therefore the b standing in line 4 preliminary switching value in the arithmetic sequence a.

As soon as a signal, which is the inverse of the signal stored in the direction memory 27 , appears at the output of the AND element 25 during a final cycle in which the AND element 25 becomes continuous, the coincidence between the actual value and the others is included in the calculation Values are present and the output unit is switched one step further. A pre-switch-off position or the end position has therefore been reached. These coincidence signals, which advance the output unit 26 by one step in the manner described, thus control the drive stages of the positioning drive via the outputs of the output unit 26. When a pre-switch-off position is reached, the next lower drive stage is switched on and, if necessary, a lower pre-switch-off value is called up. None of the pre-switch-off values in lines 4a or 4b are called up by the last drive stage (creep speed), so that the end position is now determined in the arithmetic process. If coincidence now occurs, the output unit 26 switches off its last drive stage. The end position has now been reached. Since the potential change at the carry output t15 of the last digit only takes place at a limit to the coincidence area, the two possible directions of approach of the machine part to be positioned in the target position result in a difference in the size of the travel value of the smallest digit. For this reason, as is known, a correction signal is input in the approach direction in which the switching limit would be at the end of the coincidence range, which corrects the smallest digit by one unit. The potential change thus takes place as a switching signal for the coincidence achieved in each case at the limit of the coincidence area, so that the accuracy of the path control is the same regardless of the approach direction.

In the exemplary embodiment according to FIG. 3 , the offsetting of the pre-switch-off values is moved to the end of the calculation process, ie in line 5 . The actual value J is then already in line 4. As a result, the direction is newly output at the carry memory U4 for the actual value J for each calculation and the direction memory 27 is not controlled via the output unit 26 . The direction signal that occurs after each calculation in the final cycle via an AND element is always effective at the direction memory 27 , so that the risk of an incorrect calculation result caused by interference with regard to the calculated direction is excluded for the entire positioning process, because with each of the As a result of the arithmetic operation in progress, the direction output is new. From the carry memory U5 of the last line "in which the pre-shutdown values are called up in the manner already described, the output unit 26 is controlled in the final cycle by the ring counters Z1 and Z2 via the AND element 25 , which in turn then controls the various The switching of the output unit 26 always takes place when there is an L signal at the output of the AND element 25, regardless of the position of the direction memory 27. In this embodiment, an output unit 26 is required which only has to have as many counting levels as how speed levels are to be switched. In the versions described so far, the necessary sub-clocks were created by the internal computer itself. Likewise, the operation counter consisting of the two ring counters Z1 and Z2 can be preceded by a further counter that forms the sub-clocks for the internal computer. In this case the internal computer n och simpler in its structure.

The exemplary embodiments have been used for the calculation to provide a better overview described by numerical values in a coordinate. 'The control system can be controlled with few additional switching means for the simultaneous calculation of the numerical values apply multiple coordinates. In this case the column lines are connected to the Digits of the numbers of all coordinates connected, so that when the column is called the equivalent digits of all coordinates are recorded. The line call on the other hand is from a counter 3r connected downstream of the operation counter with many counting stages, how coordinates are to be calculated at the same time And elements connected upstream. The AND terms of the lines in a coordinate are common on an output of the counter connected downstream of the operation counter, while the second inputs of the AND elements in the manner previously described with the Outputs of the ring counter ZI for the line call are connected.

This circuit arrangement ensures that, after all numerical values of a coordinate have been calculated, a switch is made to the next coordinate. The next calculation therefore records the numerical values in the second coordinate. The existing coordinates are included one after the other in the computer, with the switch being made to the first coordinate again after the last one. Since the - calculation process is determined by the clock frequency 'and are each only a fraction increases from seconds, it is seen that the offsetting all coordinates in succession has no adverse effect on the accuracy of the path control system, segment manner are four digits in a logical (Fig. 4) Circuit execution shown. Each digit consists of a tetrad, i.e. four memories, each of which is followed by an AND element. The AND elements of all digits arranged in row 1 are connected to a common row line at the first output of the ring counter Zl. In the same way, the AND elements of all digits arranged in row 2 are connected to a common row line at the second output of the ring counter Zl. In addition, all AND elements of the digit position of a column 11 are routed together to the first output of the ring counter Z2 and are equally located the AND elements of all digits in column 12 together at the second output of the ring counter Z2. The outputs of all AND elements, which represent binary digits of equal value within the tetrads, lead via OR elements to the internal computer 21. In this case, since one digit occurs as a tetrad, the internal computer 21 has four inputs assigned to the binary positions of the tetrads.

An identical section with four digits in two columns and two lines is shown in FIG. 5 as a switching variant with contacts. '-. *. e Ko-i' -, kte can be, for example, contacts of a stepping mechanism, a relay memory or a decade switch, with which the position values are specified. Each digit consists in turn of a tetrad with four contacts. The contacts in a row 1, 2 are connected together via diodes (AND conditions) to a row line at the first output of the ring counter ZI. In the same way, the contacts of line 2 are connected to the second output of the ring counter Zl. Because the binary digits 22 and 23 do not appear at the same time in a tetrad for representing a decimal, the contacts for both of these binary digits can be connected to a diode. In each column 119 12, the contact outputs of the binary digits that are equivalent within the tetrads are interconnected. The four outputs arising in each column 119 1,2 are routed to OR elements, the other inputs of which are jointly connected to the column call line. The OR elements are followed by negators. The outputs of the negators of all columns, which are assigned to the same binary digits of a tetrad, lead via an OR element to the internal computer 21. In this example, this is also designed for the parallel offsetting of a tetrad. In the circuit arrangement shown, the inverse output signals of the counters Z1 and Z2 are used.

From these switching examples, you can choose any of the rows and columns can be expanded, you can see that by calling up the columns and rows only one digit is switched on, which sends its outputs to the internal computer gives. The circuits within a digit can be offset for the Position values can be structured in different ways. Only the row and column lines and their connection to the digits is important for the switching system. With the present switching system, a path control is created that with a minimum of reduced circuit complexity and thereby all requirements a universal control. Several axes can be operated at the same time are, so that the circuit complexity increases only to the extent that memory and Output means per axis are required. All other switching elements, such as operation counters and computers are only required once. The circuit is except as a positioning control Can also be used as a scatter token control on machine tools.

Claims (2)

Patent claims: 1. Numerical path control system, in particular for machine tools with an operation counter for serial information processing and an internal computer, the numbers to be calculated , which represent position values and pre-switch-off values, are stored and the internal computer is supplied with equivalent digits of two numbers and, after accounting, forwarded to a computer memory , whereby the carry output from the highest digit position for the direction decision is fed to a direction memory and the potential change of the carry output is fed to an output unit, to whose outputs the relays for the speed levels of the drive are connected, characterized in that the equivalent digits of all numbers are successively from one of two ring counters (Z1) (Z2) are called up existing operation counter and fed to the internal computer (21) for billing, in such a way that at each output of the first ring counter (Z1) one line iteration (1 ... 5) and a column line (11..14) is connected to each output of the second ring counter (Z2), which are routed to AND elements assigned to the digit memories, which are connected in a matrix-like manner by row and column lines, the outputs of which lead to the internal computer (21) via OR elements, with the sum circulating between the internal computer (21) and the arithmetic memory (22) until the equivalent digits of all numbers are offset, with the transfers resulting from the offset in one of the The number to be calculated and the carry memory ( U2 ... U5) assigned to its line line (2 ... 5) are entered and when the next higher digit position is calculated, the outputs of the carry memory (tJ2 ... tJ5) are assigned to an input ( 24) of the internal computer (21) are performed and the carry memory 05) is connected to an input of an AND element (25) whose further inputs are connected to the last counting stages of the Rin The counter (Z1 ; "72) and its output is connected to the output unit (26) , which calls up the corresponding pre-switch-off values and is switched on from the carry output (24) of the highest digit. 2. Circuit arrangement for the numerical route control system according to Claim 1, for controlling multiple coordinates, characterized in that the column lines are connected to the digits of the numbers of all coordinates and a further counter is provided, the outputs of which are the row lines of the numbers of a coordinate with the Ring counter outputs connects. 3. Numerical path control system according to claim 1 and 2, characterized in that the actual value is calculated last and the output unit (26) controls the direction memory (27) in addition to the relay for the speed levels. 4. Numerical path control system according to claim 1 and 2, characterized in that the pre-cutoff value is calculated last according to the actual value and the output of the carry memory (filt) of the actual value is connected to the direction memory (27) . 5. Circuit arrangement for the numerical path control system according to claim 1 to 4, characterized in that the output unit (26) is designed as a counter. 6. Circuit arrangement for the numerical route control system according to claim 1 to 5, characterized in that the column lines of all pre-cutoff values are connected in parallel to the ring counter (Z2) and the row lines AND - elements are arranged upstream to which the ring counter output is connected and the other inputs of the and Members are each connected to the associated counting stage of the output unit (26) . 7. A circuit arrangement for the numerical path control system according to claim 1 to 6 characterized gekennzeichnetg that the ring counters (Zl, Z2), a counter is connected upstream for generating auxiliary clocks.