DE2309769C3 - Device for controlling a movement by continuously setting at least one position coordinate register as a function of the movement of an encoder - Google Patents

Description

Another embodiment of the device according to the invention is characterized by such an embodiment of the electronic arithmetic unit that there are acceleration change values calculated and at an output in code form for transmission to the electronic computer provides

Furthermore, a device according to the invention is characterized by one in the electronic arithmetic unit provided converter, which the values to be transmitted to the electronic computer in code form (Values of the acceleration or the change in acceleration) below a specified limit.

Further features of the invention are the subordinate claims removable.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawings.

F i g. 1 shows a schematic representation of a roller ball encoder;

F i g. 2 shows the structure of an electronic arithmetic unit for the formation of acceleration codes to be transmitted to an electronic computer;

3 shows the structure of an electronic arithmetic unit for the formation of acceleration change codes to be transmitted to an electronic computer.

In Fig. 1, 1 is a dome-shaped housing in which a roller ball 2 is mounted so that it can rotate freely in all directions so that it protrudes downward from the housing with a small dome. The track ball 2 can be rotated in all directions by moving the housing 1 on a fixed surface 3 in the corresponding directions, the track ball 2 rolling on the surface 3. This track ball encoder is used to move a mark on the screen of an electron beam monitor tube. For this purpose, a movement component of the roller ball 2 is represented by a friction wheel 4 as an x (horizontal) component and the movement component of the roller ball perpendicular to it is represented by a friction wheel 5, the axis of which is in the same plane as that of the friction wheel 4 perpendicular to it, as y - (Vertical) component tapped. A pulse generator disk 6x is connected to the friction wheel 4 for common rotation, and an identically designed pulse generator disk % y is connected to the friction wheel 5. Ta and Tb are schematically illustrated discharge devices which are provided in this way for both code disks 6, v and 6y . A pushbutton 8 protrudes from the upper part of the housing 1 and, when the screen marker is to be moved by shifting the housing 1, is depressed with the palm of the hand and a changeover contact 9 moves from a contact 10 to a contact H in the process. The terminals of the sensing devices Ta, Tb and the contacts 10 and 11 as well as the power supply lines are connected to a flexible cable (not shown) leading out of the housing 1, via which the roller ball encoder is connected to an electronic arithmetic unit.

Each pulse generator disk 6x or 6y has contacts in such an arrangement that each sensing device 7a, Tb emits a square pulse train with equidistant edges when the pulse generator disk rotates, a wiper 7c serves to supply power. Through suitable design of the contacts or mutual angular displacement of the Abfühivorrichtungen Ta, Tb , the detachable rectangular pulse trains are offset from one another by half an edge distance, which makes it possible to differentiate the directions of rotation of the pulse generator disc in a known manner and to derive counting pulses from the rectangle pulses appear either at an upward or downward counter output of a discriminator, depending on the direction of rotation.

In the block diagrams F i g. 2 and F i g. 3 is the pushbutton mechanism 8 to H of FIG. 1 denoted by TA , a pulse generator disk together with Abfühivorrichtungen 7a, Tb with RK and the aforementioned, this pulse generator disk associated discriminator with D. For the following, the pulse generator disk may be the pulse generator disk 6x for the x-direction; all devices described below are provided in the same way for the y-direction, with the exception of devices N and TG. the two can be in common. N is a normalization signal generator, TG is a clock generator, the clock pulses T at a distance of z. B. is able to output 55 msec. Since processes to be described below repeat themselves repeatedly in these time intervals, such a line interval is referred to as a cycle. The current cycle is symbolized by the designation n, the previous one by n- 1.

With Rt is a countable in both counting directions, z. B. eight-digit binary register, which is part of an electronic arithmetic unit located at the location of the roller ball encoder and a display device. The pulses emitted by RK when the trackball moves are fed to the lowest position of the register Ri as counting pulses which, depending on the information provided by the discriminator D, are upward or downward counting pulses. At the beginning of a cycle, the register Ri is first normalized, then the counting increments, which correspond to coordinate increments, add up during the current cycle to an amount DxRn , which has the dimension of a speed. A register Rl, in which at the beginning of the cycle a speed value Dxn- 1 calculated for the previous cycle, as indicated below, is contained, is linked to the register Ri by a subtraction network S1, which calculates the difference in the contents of the two registers, forms an acceleration value bn . In the embodiment of the electronic arithmetic and logic unit according to FIG. 2 is fed to a converter U , which, if the absolute amount of bn is less than or equal to 6, forwards the positive or negative acceleration value in the form of a four-digit binary code, but in all cases where the absolute amount of bn is greater than or equal to 7 the converter U always outputs a code of the value 8 with a positive or negative sign.

The converter U of FIG. 2 output code is once transmitted to a remotely located electronic computer ER and supplied to the other in the electronic calculating unit an adder Al, which is connected to the register Rl and optionally transformed, namely reduced acceleration amount bri in the register Rl correct sign einaddiert which a so contains calculated speed amount Dxn = Dxn- 1 + bn ' for comparison with the "measurement result" in register Ri of the following cycle and thus for the formation of a new acceleration value, which in turn, possibly limited in converter U , transmits to the remote electronic computer ER and also in the local electronic arithmetic unit is processed as specified.

The registers of the electronic arithmetic unit (according to FIG. 2 that is, Ri and R2) are released when the

Key 8 (Fig. 1) and thus the potential applied to contact 10 is held normalized, while pressing key 8 and thus applying potential to contact II brings the clock generator TG into effect. The electronic computer ER receives the acceleration values while the roller ball encoder is actuated. as indicated, for the x- and ^ -direction and is able to use these values to determine the content of an a- and a / -Positionskoordinatenregister, according to the content of which the position of a mark on the screen of the display device can be set, in the same way to change how the content of the register Rl changes, whereby the mark runs at a corresponding speed across the screen. The movements of the mark do not get out of control even at very high accelerations that are manually transmitted to the trackball.In such cases, due to the limitation of the acceleration values transmitted to the computer, the mark only moves more slowly in the desired direction than it corresponds to the encoder speed about 'the screen. The effect of the converter U, which, as stated, also limits negative accelerations, i.e. deceleration values and is comparable to the mass of a flywheel, has the consequence that with high deceleration values a brief "overshoot" of the mark movement occurs after the end of the encoder movement, if repeated Subtractions of the maximum delay value (-8) take place until the contents of the register R2 are reduced to zero.

If the data flow is restricted to one bit octade per cycle, the acceleration values for χ and y can be transmitted one after the other with a four-digit code each. It is provided that three digits of the acceleration code to be transmitted for each coordinate indicate the absolute values "zero" to "six" of the acceleration in binary code, so that the maximum triple LLL is not the acceleration value 7, but (based on practical tests) the higher value 8 should denote and that the fourth code indicates the sign of the acceleration by using z. B. = 0, for delays = L. With the specified type of use of the maximum triple LLL , in order to achieve a normal binary adding process in adder A2, it is advisable to provide a logic part in converter U which feeds the "real" binary value eight positive or negative to the adder instead of the mentioned triple.

A readjustment z. B. a screen brand with approximately the aids described above can also be used in be effected in such a way that the codes to be transmitted to the electronic computer change in acceleration include. An example of an electronic arithmetic logic unit to be designed for this purpose is in Fig. 3, parts recurring that have already been described and, as in FIG. 2

■ ο are designated.

In the electronic computing device according to FIG. 3, the acceleration value that can be taken from the subtraction network Si at the end of a cycle is used; it is now designated as the "current" acceleration value with bRn.

> 5 net, entered in a register /? 4, which was deleted at the beginning of the cycle. A register R3, in which an acceleration value bn - Γ determined for the previous cycle is contained at the beginning of the cycle, is connected to the register /? 4 by a subtraction network S2 , which forms the difference between the contents of the two registers, an acceleration change value dbn . This acceleration change value is fed to a converter U, which can again be designed as explained above. The converter U outputs an acceleration change value dbri , which can be coded and limited in the same way as was previously described for the acceleration value bn '. This value is transmitted to the electronic computer ER removed and further, advantageously also shown here in pure binary form, supplied to an adder A4, the bn the value 'in the regi-art R3 einaddiert, whereby this register bn a respective current calculated acceleration value. As with F i g. 2, the same value bn 'is added to register R2 , which keeps track of the current calculated status of the speed so that a new current acceleration value bRn can be generated based on the speed value measured in register Ri during the next cycle . The electronic computer has to calculate the current acceleration for each cycle from the acceleration change values transmitted! and to keep this book, as is the case in register Rl , and from this again the current speed in a register corresponding to R2 to images according to the content of which the screen mark can be controlled.

1 sheet of drawings

Claims (7)

Patent claims: 1. Device for controlling a movement by continuously setting at least one register of an electronic computer in accordance with position coordinates depending on the movement of an encoder, with at least one encoder actuated by the encoder movement being provided as well as an evenly timed interrogation device which Queries the time available code and transmits it to the electronic computer, which calculates a value for the controlled positioning from this and enters it in the register, characterized in that the encoder (Fig. 1) moves coordinates (nkremenie in a manner known per se as pulse sequences outputs that allow the direction of movement to be discriminated, and that an electronic arithmetic unit (Fig. 2 or 3) is provided as a code generator for forming the codes to be transmitted to the electronic computer, which picks up the pulse sequences and uses them to calculate acceleration values. 2. Device according to claim 1, characterized by an output of the electronic arithmetic unit (F i g. 2), via which the acceleration values are transmitted in code form to the electronic computer (ER). 3. Device according to claim 1, characterized by such a design of the electronic arithmetic unit (F i g. 3) that it calculates acceleration change values and provides them at an output in code form for transmission to the electronic computer (ER). 4. Device according to claim 2 or 3, characterized by a converter (U) provided in the electronic arithmetic unit, which keeps the values to be transmitted to the electronic computer in code form (values of the acceleration or the change in acceleration) below a predetermined limit. 5. Device according to claim 1 or 2, characterized by an actuated by the pulse trains, countable in both directions, the coordinate increments counting each during the duration of a clock interval register (Al) and a computing device (Sl, U, -42, R2), the in each clock interval compares the content of this register with a value determined by the previous clock intervals and determines an acceleration value in code form. 6. Device according to claim 3, characterized by a register (A4), in which an acceleration value determined in this is entered for each clock interval, and a computing device (52, U, A4, R3), which with the content of this register in each clock interval compares a value determined by the accelerations of previous clock intervals and determines an acceleration change value in code form. 7. Device according to claim 5 or 6, characterized by a converter (U) which transforms codes whose value exceeds a predetermined limit into a code of a fixed value lying at or near this limit. The invention relates to a device for controlling a movement by continuous adjustment at least one register of an electronic computer as a function of position coordinates from the movement of an encoder, with at least one encoder actuated by the encoder movement is provided, as well as an evenly clocked interrogation device, which with each clock to this Queries the time available code and transmits it to the electronic computer, which uses this to calculate a value of the controlled Positioning calculated and entered in the register. Such a device is known from the German Offenlegungssch: ift 19 16 348. A trackball of the encoder to be moved here mechanically actuates a code disk for each coordinate direction, which provides a sequence of position codes depicting this section in several sectors of the same size once for a given section of the movement component falling in this coordinate direction, and it is queried by the electronic computer in the interrogation cycle an expected value of the controlled positioning is calculated from several last consecutively queried position codes, corrected in accordance with a residual class determination, the most recently queried position code and, if necessary, an initial correction value, and the result is entered in the relevant position coordinate register.
In particular, it is provided that the point of impact of the electron beam of a screen tube can be set using the respective contents of the position coordinate register of the electronic computer, so that a mark is moved on the screen according to the encoder movements. The transmission of the codes from the encoder to the electronic computer is less, z. B. from a usual Teletype provided bandwidth feasible than would be required when looking at the position coordinates register in the way of the coordinate increments corresponding upward and downward counting would operate by encoder pulses, which is also known, especially in the form that for two square-wave pulse trains are transmitted to each register, their mutual phase position determining the counting direction determined (as indicated in dei DT-OS 15 49 916). In the known device according to the German patent application 19 16 348, however, results Promotion that sudden significant changes in speed of the encoder must be avoided, because otherwise the controlled movement can get out of control. The object of the invention is to create a device in which the aforementioned requirement given restriction does not exist. According to the invention it is provided in a device of the type mentioned that the encoder at its movement outputs coordinate increments in a manner known per se as pulse trains that indicate the direction of movement to discriminate jammed, and that as a encoder to form the to the electronic computer An electronic arithmetic logic unit is provided for the transmitted codes, which records the pulse trains and from this, acceleration values are calculated. ^h 5 In particular, an output of the electronic arithmetic unit is provided, via which the acceleration values are transmitted to the electronic computer in code form.