JPS58219604A - Fixed time control system of microcode - Google Patents

Abstract

PURPOSE:To control a feeding mechanism for documents, etc., with high precision by programming the control logic of a feedback loop, holding the number of steps constant, and performing fixed-time control over a sampling period, manipulated variable output, etc. CONSTITUTION:When an address is increased by an incrementer 3 by inputting a clock, areas of digits 2<0>-2<6> of a microprogram memory 2 are accessed to read microcodes, and an arithmetic logical element 1 performs operations by the specification of the microcodes. This system has four modes; and microcodes of a main routine and a subroutine for position control under which a speed is varied following up a target speed are stored in addresses 0-127 and 128-255, and microcodes of a main routine and a subroutine for stop control are stored in addresses 256-511. Further, microcodes of a main routine and a subroutine for open loop control are stored in addresses 512-767, and microcodes are stored in addresses 768-1023. Then, four kinds of processing are performed by the output of a latch 4 according to instructions from a high-order control part.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to a microcode fixed time management method,
In particular, the present invention relates to a digital control system for drive servo motors used in devices that require highly accurate control of position and speed using microprocessors, such as in document and paper feed mechanisms.

Prior art DC servo motors are controlled by a sample value control loop consisting of a p-tary encoder and a manipulated variable calculation circuit. In sample value control, as shown in Figure 1, the rotational speed of a DC servo motor is changed from a certain value A to a value B.
to change it to.

Although it is possible to pass through various curves, the speed value is controlled using a curve that connects the values obtained from the construction date as the target. That is, the actual value with respect to the target value at each time, that is, the control deviation, is extracted at a certain time interval (sampling period) Δt and sent to the control device as a sample value signal.

The output from the control device is given to the DC servo motor to be controlled as a stepped continuous operation amount by a hold element.

Conventional manipulated variable determination means were constructed with an analog/pg circuit, but it required correction of errors due to component constants, temperature changes, etc., and required sophisticated circuit technology and adjustment technology. Therefore, digital control using a microprocessor, etc. is being considered, but in order to perform high-precision control, it is necessary to execute different types of control logic and condition judgment branches, and the number of steps varies depending on the control flow. There was a drawback that the amount output timing was not constant. For example, the form feeding mechanism
If control is performed according to the curve shown in Figure 1,
Since the target value must be achieved every sampling period, it is necessary to keep the manipulated variable output timing constant. To do this, the number of steps in the microcode must also be constant.

Purpose of the Invention The purpose of the present invention is to solve the above-mentioned feedback loop.
In order to implement control logic such as manipulated variable calculations in a program using a microprocessor, we provide a fixed time management method for microcode that allows branching of the control flow and at the same time keeps the number of steps constant. It's about doing.

Detailed description of the invention.

The present invention provides a program counter that determines the sequence of instructions (microcode) to be given to an arithmetic logic element by configuring it with a combination of an incrementer and a latch.
The present invention is characterized in that it is possible to jump to other modes such as acceleration/deceleration and stop state while branching between two routines of the same step, and that the processing time is kept constant.

Embodiment of the Invention FIG. 2 is a block diagram of an address control unit for microcode fixed time management showing an embodiment of the invention.

1 is an arithmetic logic element, and 2 is a gram memory with a microb for controlling this element. 2 is the IK word (
This is a FROM (1 word - 24 bits). 3 is an incrementer that performs normal counter operation. 7 bits become addresses 2° to 2b of memory 2, and free run occurs. 4.5 is a latch, and the convex portions are connected to addresses 27.4, 28, and 2@, respectively. Four different processes can be performed by the output of the launcher 4 according to instructions from the higher-level control unit. The latch 6 is set when a condition is satisfied in a microcode conditional judgment branch instruction, and it is also possible to return, making it possible to branch between two 0-127 step routines.

FIG. 3 is a time chart of the macro program routine of the present invention.

As shown in FIG. 3, in this embodiment, the main routine (
There is only one level of subroutines (SR) in addition to MR). When the main routine (MR) is executed and the condition is met by the condition judgment branch instruction in the microcode, the process branches to the subroutine (SR).
Then, at a certain step, an unconditional return plane is performed and the process returns to the main routine (MR). Main routine GvI)'
If the conditions of the condition judgment shunting command are not satisfied in step t), the vehicle continues traveling. In this case, in a normal processor, after branching to a subroutine and completing its processing, the processor returns to the instruction next to the branch instruction in the main routine, but in the present invention, the number of processing steps is fixed (0 to 127 steps). Therefore, when returning to the main routine,
Return to the address next to the subroutine address in the digits 2° to 26. For the second digit, if the latch δ is set to "1", the subroutine (SR) is executed, and if the latch δ is set to "0", each step of the main routine (MR) is executed. Then, the sampling period Δt
is fixed at 128 steps of the microcode, the deviation from the target value is calculated, and the manipulated variable given to the DC servo motor is output. For example, in order to achieve the target speed, the main routine's Aφ' step refers to the display output of temperature changes, etc., and if there is a change of more than a certain i, the main routine adds the value, but if there is not much of a change, the subroutine After branching and proceeding with only one step without doing anything, perform an unconditional return to the main routine. In addition, it is necessary to separate the two types, such as multiplying X and Y in the main routine, and dividing X and 2 in the subroutine when different conditions exist, so the level of the subroutine is reduced to 1.
By providing the above, control becomes easier. In FIG. 3, there is one level of subroutines, but there may be two or more levels.

FIG. 4 is a diagram showing the information storage state of the program memory in FIG. 2, and FIG. 5 is an explanatory diagram of the usage state of each mode in FIG. 4.

Here, each of the four main and sub-routines is position control during motor acceleration/deceleration and constant speed, open-loop control during startup, stop control during stop, and diagnostic mode for self-diagnosis. have.

The incrementer 3 increments the address according to the input of the clock, accesses the 2-2 digit area of the microprogram memory 2, reads the microcode (24 bits), and the arithmetic logic element 1 reads the address according to the specification of the microcode. Perform calculations. In this case, since it is not possible to smoothly control the DC servo motor with only one mode, four modes are prepared here. That is, addresses 0 to 127, 1
Addresses 28 to 255 store main and subroutine microcodes for position control that detects the motor operation, feeds it back, tracks it to a target speed, and changes the speed, and addresses 256 to 511 store it. Main and subroutine microcode for stop control is stored. That is, as shown by D in FIG. 5, it is easier to control the part where the motor stops by using a stop control program in a separate mode than by controlling the position when the motor is moving. 51
At addresses 2-'r67, the open loop control main,
Contains subroutine microcode. That is, as shown by C in FIG. 6, when the motor starts,
Since there is no feedback information, there is a risk of malfunction in closed-loop control, and in this case as well, a separate mode of open-loop control program is used to provide an appropriate control output. Also, at addresses 768-1023,
Contains diagnostic main and subroutine microcode. In other words, it is necessary to test whether the control system is operating normally, whether the arithmetic elements are operating correctly, or whether each output is normal. For this purpose, a separate mode of diagnostic program is required. In the present invention, high-level branching such as relative address jump, which is unique to programming, is not possible, but on the contrary, these functions are unnecessary in sample value control of a servo motor, etc. A microprocessor suitable for sample value control is constructed by simplifying the function to the extent that it satisfies the function of four-gram processing. In other words, it is possible to realize address management based on running time while satisfying the functions of a program, and it is also possible to self-diagnose the hardware unit.

Furthermore, by using the upper bits of the incrementer 3 as a motor selection signal, it is also possible to control a plurality of motors. In this case, the program counter can be configured with relatively simple hardware, which is advantageous both technically and economically when controlling a plurality of motors. The hardware design is also simpler, and the implementation efficiency is improved by about 20% compared to the conventional one.

Effects of the Invention As explained above, according to the present invention, control logic such as operation amount calculation in a feedback loop is realized by a program using a microb 47, and the number of steps is always constant, and the sampling period is Since the output of the manipulated variable and the like can be managed at a fixed time, extremely high precision control is possible when applied to the feed mechanism of the paper and paper industry.

[Brief explanation of drawings]

Figure 1 is a curve diagram of sample value control of a DC servo motor.
FIG. 2 is a block diagram of an address control unit for microcode fixed time management showing an embodiment of the present invention, FIG. 3 is a time chart of the microprogram routine of the present invention, and FIG. 4 is a microprogram in FIG. 2.・Memory information storage state diagram: FIG. 5 is an explanatory diagram of the usage state of each mode in FIG. 4. 1: Arithmetic logic element, 2: Microprogram memory,
3 = incrementer, 4.5: latch, 61 condition stern determination control circuit, Figure 1 MR 11 Figure 3 Figure 4 Figure A scale Figure 5

Claims (1)

[Claims] In a processing device that performs the control logic of a sample value control loop using a microgram, the program counter that determines the sequence of microcodes to be given to the arithmetic unit is composed of a combination of an intermenter and a latch, and different types can be generated depending on the state of the latch. A microcode fixed time management method characterized by making changes to the control logic and changing the control flow based on condition determination, and maintaining the total number of steps in the microcode at a fixed value even when the above changes are made. .