JP2010098837A - Cam operation control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cam operation control device wherein even when there is uneven rotation or speed fluctuation in the rotation mechanism of a mechanical device, an accumulated error is not produced in the position of an electric actuator. <P>SOLUTION: The cam operation control device includes a speed computation circuit 5 and a computation pulse count circuit 7. The speed computation circuit carries out the following processing: it reads speed data C for rotation angle B from a relevant address in a speed pattern memory 2 each time the rotation angle B of a mechanical device 1 varies; it obtains speed command data by multiplying the read speed data C by the rotation speed frequency D of the mechanical device 1; it accumulates the speed data D to generate target position data integrated by the speed data C and computes a position correction amount based on the amount of positional displacement obtained by subtracting the current position data from the target position data; and it adds the position correction amount to the speed command data to obtain new speed command data E. The computation pulse count circuit adds and counts computation pulses G to obtain the current position data H. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a cam operation control device in which positioning control corresponding to the rotation angle of a mechanical device having a rotation mechanism is performed by an electric actuator, and the positioning accuracy of the electric actuator for each rotation angle of the mechanical device, that is, the cam locus. It is related with the cam operation control apparatus which improved the precision of this.

For example, Patent Document 1 discloses a cam operation control device that uses an electric actuator to perform positioning control corresponding to a rotation angle of a mechanical device having a rotation mechanism, such as blanket cylinder attachment / detachment control in a printing machine. ing.
This kind of cam operation control device is provided with a speed pattern memory for storing speed data for each rotation angle obtained by differentiating the position of the electric actuator with respect to the rotation angle of the machine device by the rotation angle, and attached to the machine device. A rotation angle detection circuit that obtains the rotation angle of the mechanical device by inputting an angle pulse signal of the angle transmitter, and a rotational speed frequency proportional to the rotational speed of the mechanical device by inputting the output of the angle transmitter A rotation speed detection circuit that reads the speed data for the rotation angle from the corresponding address of the speed pattern memory each time the rotation angle of the machine device changes, and the read speed data and the rotation speed frequency of the machine device And a speed calculation circuit that obtains speed command data by multiplication with the electric actuator based on the speed command data. Can also enable difficult complex camming action achieved by the mechanical cam is characterized in that a drive means for driving the.

  Moreover, the speed command data of the electric actuator is generated by multiplying the speed data for each rotation angle obtained based on the preset positioning pattern of the electric actuator by the rotation speed frequency proportional to the rotation speed of the mechanical device, For this reason, it has the feature that positioning control can be performed without providing means for detecting the position of the electric actuator.

However, if there is rotation unevenness or speed fluctuation in the rotation speed of the rotation mechanism of the mechanical device, this becomes the frequency fluctuation of the angle pulse signal of the angle transmitter, and this is a fluctuation of the cycle in which the rotation angle changes. This cam operation control device is a big problem.
In other words, the speed data for each rotation angle stored in the speed pattern memory is obtained by differentiating the position of the electric actuator with respect to the rotation angle of the mechanical device based on the rotation angle on the assumption that the cycle in which the rotation angle changes is constant. The fluctuation of the cycle in which the rotation angle of the rotation mechanism of the mechanical device changes gives an error to the speed command data generated by multiplying the speed data by the rotation speed frequency, and causes an accumulated error with respect to the position of the electric actuator.

As a means for improving the positioning accuracy of the electric actuator due to such rotation unevenness or rotation fluctuation of the rotating mechanism, a method of providing a means for detecting the position of the electric actuator and performing feedback control can be considered, but the control is complicated. And is not economically advantageous.
Japanese Patent No. 2850081

  The problem to be solved is that if the rotational speed frequency, which is a variable proportional to the rotational speed of the mechanical device, cannot be obtained accurately, an error will occur in the speed command data obtained from the speed calculation circuit. This is a cumulative error with respect to the position, which deteriorates the positioning accuracy.

FIG. 1 is a block diagram showing the configuration of a cam operation control apparatus according to an embodiment of the present invention.
In the present invention, in order to improve the positioning accuracy of the electric actuator 12 for each rotation angle of the mechanical device 1, the speed for each rotation angle obtained by differentiating the position of the electric actuator 12 with respect to the rotation angle of the mechanical device 1 by the rotation angle. A speed pattern memory 2 for storing data, and a rotation angle detection circuit for obtaining the rotation angle B of the mechanical device 1 by inputting the angle pulse signal A of the angle transmitter 11 attached to the mechanical device. 3, a rotational speed detection circuit 4 that inputs the angle pulse signal A to obtain the rotational speed frequency D of the mechanical device 1, and the speed pattern memory 2 changes every time the rotational angle B of the mechanical device 1 changes. The speed data C corresponding to the rotation angle B is read from the corresponding address, and the speed is obtained by multiplying the read speed data C by the rotation speed frequency D of the mechanical device 1. The position correction amount is calculated based on the position shift amount obtained by accumulating the speed data C to generate target position data and subtracting the current position data from the target position data. A speed calculation circuit 5 that adds a quantity to the speed command data to obtain new speed command data E, and generates a calculation pulse G that has undergone frequency conversion based on the speed command data E, and the calculation pulse A driving pulse generation circuit 6 that generates a driving pulse signal F for driving the electric actuator 12 from G, and an arithmetic pulse counting circuit 7 that adds and counts the arithmetic pulse G to obtain the current position data H. The main feature is that

The cam operation control device according to the present invention adds the speed data read from the speed pattern memory every time the rotation angle of the mechanical device changes to obtain target position data, and adds a calculation pulse obtained by performing frequency conversion based on the speed command data. The position correction amount is calculated based on the position shift amount obtained by subtracting the current position data from the target position data as the current position data, and the position correction amount is rotated in proportion to the speed data and the rotation speed. A new speed command data is obtained by adding to the speed command data obtained by multiplication with the speed frequency, and the drive pulse signal of the electric actuator is output from the drive pulse generation circuit.
For this reason, even if there is rotation unevenness or speed fluctuation in the rotation mechanism and a cumulative error with respect to the position of the electric actuator occurs temporarily, cam operation is performed while correcting the speed command data with the position deviation as the position correction amount. The positioning accuracy of the electric actuator, that is, the accuracy of the cam trajectory can be improved.

  Using a microcomputer, the functions of the speed pattern memory and the speed calculation circuit were realized by software of the microcomputer.

  FIG. 2 is a block diagram showing the configuration of an embodiment of the apparatus of the present invention, in which 21 is a read-only memory (hereinafter referred to as ROM), 22 is a processing device (hereinafter referred to as CPU), and 23 is a cam operation setting device. , 24 is a random access memory (hereinafter referred to as RAM), 61 is a binary rate multiplier, and 62 is a frequency divider. A1 is an angle origin signal, A2 is a cam operation start signal, and B1 is an interrupt request signal. 1, 3, 4, 7, 11, 12 and A to H are the parts and signals having the same functions as those in FIG.

In FIG. 2, a CPU 22, ROM 21 and RAM 23 form a so-called microcomputer, and the functions of the speed pattern memory 2 and the speed calculation circuit 5 are also realized by software.
The ROM 21 stores a program to be processed by the CPU 22 for cam operation control, and stores a plurality of speed patterns for positioning the electric actuator 12.
The cam operation setting device 23 is a setting device for causing the CPU 22 to select which of the plurality of speed patterns stored in the ROM 21 is used to control the positioning of the electric actuator 12, and for example, attaching and detaching a blanket cylinder in a printing machine. In the case of control, the printing paper thickness is set, and the CPU 22 selects a speed pattern corresponding to the paper thickness.

The angle transmitter 11 is incorporated in the rotation mechanism of the mechanical device 1. When the rotation mechanism of the mechanical device 1 rotates, the angle transmitter 11 generates an angle pulse signal A and an angle origin signal A 1, and the angle pulse signal A is converted into a rotation angle detection circuit. 3 and the rotation speed detection circuit 4, the angle origin signal A1 is output to the rotation angle detection circuit 3, respectively.
The angle pulse signal A is a pulse signal generated at every angle obtained by equally dividing one rotation. For example, when one rotation is divided into 360 equal parts, one pulse is generated every one degree. The angle origin signal A1 is 1 This is a pulse signal that occurs once per rotation, and occurs when it changes from 359 degrees to 0 degrees, for example.

The rotation angle detection circuit 3 is configured by a counter circuit that inputs and counts the angle pulse signal A and inputs the angle origin signal A1 to preset the angle origin, and the rotation angle B of one rotation of the rotation mechanism of the mechanical device 1. And an interrupt request signal B1 is output to the CPU 22 every time the rotation angle B changes.
The rotation speed detection circuit 4 measures the frequency of the angle pulse signal A and holds the rotation speed frequency D of the rotation mechanism of the mechanical device 1. Both the rotation angle B and the rotation speed frequency D can be read from the CPU 22. ing.

The binary rate multiplier 61 and the frequency divider 62 constitute a drive pulse generation circuit 6.
The binary rate multiplier 61 outputs a pulse train having a frequency obtained by multiplying a reference clock frequency (not shown) by a ratio having 2 ^N as a denominator and a ratio setting value as a numerator, where N is the number of bits. The speed command data E is input from the CPU 22 to generate a ratio setting value and generate a calculation pulse G.
If a high-accuracy ratio calculation is to be performed by the binary rate multiplier 61, the number of bits must be increased and the reference clock frequency must be increased. The driving pulse frequency to be obtained cannot be obtained.
The frequency divider 62 is a binary counter that performs frequency matching between the calculation pulse G and the drive pulse signal F.

The arithmetic pulse counting circuit 7 receives the arithmetic pulse G from the rate multiplier 61 and counts it, and holds the current position data.
The current position data can be read from the CPU 22.

Next, a speed pattern memory realized by the CPU 22, the ROM 21, and the RAM 24 will be described with reference to FIG.
FIG. 3 shows an example of the configuration of the speed pattern memory and shows the relationship between the address of the speed pattern memory and the speed data for each rotation angle.
One speed pattern stores speed data for one rotation for each rotation angle. In FIG. 3, speed data is stored for each rotation angle from 0 to 359 degrees. Then, the speed data v (θ0) at the rotation angle 0 degree is at the head address of one speed pattern, the speed data v (θ1) at the rotation angle 1 degree is at the head address +1, and the head address +2 ), The speed data v (θ2) at the rotation angle of 2 degrees is in ascending order of the rotation angle, and the speed data v (θ359) at the rotation angle of 359 degrees is the last (first address + 359) address. Is stored.

  In one embodiment of the apparatus of the present invention, a plurality of such speed patterns are stored in the ROM 21, and the CPU 22 is made to select a speed pattern for performing positioning control of the electric actuator 12 according to the setting of the cam operation setting device 23. However, every time the setting of the cam operation setting device 23 changes, the CPU 22 performs an operation for differentiating the position of the electric actuator 12 by the rotation angle in accordance with the setting, and the speed pattern obtained thereby may be stored in the RAM 24. In this case, the configuration of the speed pattern memory is the same as that shown in FIG.

Next, a speed calculation circuit realized by the CPU 22, the ROM 21, and the RAM 24 will be described with reference to FIG.
FIG. 4 is a flow chart of speed calculation. After the cam operation start signal A2 is input to the CPU 22 from the mechanical device 1, the interrupt process executed by the CPU 22 by the interrupt request signal B1 input from the rotation angle detection circuit 3 is shown. It is shown.
In FIG. 4, S1 (or S1-1 to S1-3) to S7 indicate processing steps in the interrupt processing.

If the cam operation start signal A2 is input from the mechanical device 1 and the interrupt request is received when the rotation angle B input from the rotation angle detection circuit 3 is 0 degrees, the cam operation is started and processing steps S1-1 to S1- 3 is executed to initialize the cam operation.
(S1-1)
A speed pattern address pointer (not shown, present in the software of the CPU 22) for indicating the address of the selected speed pattern in the speed pattern memory is cleared to 0 to indicate the head address of the speed pattern.
(S1-2)
The calculation pulse counting circuit 7 is reset to clear the current position data H to 0, and the calculation current position data Pn (not shown in the software of the CPU 22) is set to 0.
(S1-3)
The target position data Pt (not shown, present in the software of the CPU 22) obtained by integrating the speed data is cleared to zero.

After the cam operation is started, if the interrupt request is for the rotation angle B from 1 degree to 359 degrees, the cam operation is being performed and processing steps S1 to S7 are executed. Processing steps S2 to S7 are also executed in the cam operation start flow.
(S1)
1 is added to the speed pattern address pointer for indicating the address of the selected speed pattern in the speed pattern memory to indicate the address of the speed data at the next rotation angle.
(S2)
The speed data is read from the address of the ROM 21 pointed to by the speed pattern address pointer and is set to v (θ).
(S3)
The rotational speed frequency D is read from the rotational speed detection circuit 4 and set to ω.
(S4)
The current position data H is read from the arithmetic pulse counting circuit 7 and scaling processing is performed to set the current position data for calculation to Pn.
(S5)
v (θ) × ω × K + (Pt−Pn) × G is calculated and the result is set as speed command data E.
Here, K and G are coefficients.
(S6)
The speed command data E is written to the binary rate multiplier 61 as a ratio set value.
(S7)
The speed data v (θ) is added to the target position data Pt to obtain new target position data Pt.

  As described above, every time the rotation angle B changes, the interrupt request signal B1 is generated from the rotation angle detection circuit 3. In the interrupt processing, the CPU 22 rotates from the corresponding address of the ROM 21 constituting the speed pattern memory 2 in the processing step S2. The velocity data v (θ) for the angle B is read out, and in step 5, the velocity data v (θ) × ω × K is obtained by multiplying the velocity data v (θ) and the rotational angular frequency ω, and in processing step S7. The position data (Pt) obtained by subtracting the current position data Pn for calculation from the target position data Pt at the time of the previous interruption process in processing step S5 so as to generate the target position data Pt by integrating the speed data v (θ). −Pn) is multiplied by a coefficient G to calculate a position correction amount (Pt−Pn) × G, and the position correction amount is calculated as the speed command data v (θ) × ω. And added to K so as to obtain a new speed instruction data E realizes a function of speed calculation circuit 5.

In the device according to the present invention, every time the rotation angle B changes, the position correction amount calculated from the position shift amount is added to the speed command data to obtain new speed command data E. The rotation speed frequency D fluctuates due to the presence of rotation irregularities and speed fluctuations in the electric actuator 12.
Even if a cumulative error with respect to the current position temporarily occurs, the cam operation can be performed while correcting the speed command data using the position deviation as the position correction amount, that is, the positioning accuracy of the electric actuator 12, that is, the cam locus This has the effect of improving accuracy.

  The present invention can be applied to a positioning device in which a speed pattern of the electric actuator is generated in advance and the electric actuator is positioned based on the speed data of the speed pattern.

It is a block diagram which shows the structure of the cam operation control apparatus of embodiment of this invention. It is a block diagram which shows the structure of the cam operation control apparatus of embodiment of this invention. Speed pattern memory configuration example Flow chart of speed calculation

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mechanical apparatus 11 Angle transmitter 12 Electric actuator 2 Speed pattern memory 21 Read-only memory (ROM)
22 Processing unit (CPU)
23 Cam operation setting device 24 Random access memory (RAM)
DESCRIPTION OF SYMBOLS 3 Rotation angle detection circuit 4 Rotation speed detection circuit 5 Speed calculation circuit 6 Drive pulse generation circuit 61 Binary rate multiplier 62 Divider 7 Calculation pulse count circuit A Angle pulse signal A1 Angle origin signal A2 Cam operation start signal B Rotation angle B1 Interrupt request signal C Speed data D Rotational speed frequency E Speed command data F Drive pulse signal G Operation pulse H Current position data

Claims (1)

  A speed pattern memory for storing speed data for each rotation angle obtained by differentiating the position of the electric actuator with respect to the rotation angle of the machine device by the rotation angle, and an angle pulse of an angle transmitter attached to the machine device A rotation angle detection circuit for obtaining a rotation angle of the mechanical device by inputting a signal, a rotation speed detection circuit for obtaining a rotation speed frequency of the mechanical device by inputting the angle pulse signal, and the machine Each time the rotation angle of the apparatus changes, speed data for the rotation angle is read from the corresponding address in the speed pattern memory, and speed command data is obtained by multiplying the read speed data by the rotation speed frequency of the mechanical device. And obtaining the target position data by integrating the speed data and subtracting the current position data from the target position data. Based on the new speed command data, a speed calculation circuit that calculates a position correction amount based on the position shift amount and adds the position correction amount to the speed command data to obtain new speed command data. A drive pulse generation circuit for generating a calculation pulse having undergone frequency conversion and generating a drive pulse signal for driving the electric actuator from the calculation pulse, and adding the calculation pulse to obtain the current position data A cam operation control device comprising a calculation pulse counting circuit configured to count.

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