JPS6023598B2 - Motor speed setting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor speed setting device for controlling acceleration and deceleration of a motor.

FIG. 1 shows a block diagram of this type of device as a follower.

This device includes a △xU calculation circuit 11 that uses input data xU and tU as input signals to calculate an increase △xu during up-counting, and a △xU calculation circuit 11 that uses input data xd and td as input signals to calculate a decrease △xd during down-counting. △xd calculation circuit 12 that calculates △xd, a contact 13 that is turned on with acceleration command UP and allows △xU to pass, and a contact 13 that is turned on with deceleration command DOWN and allows △xd to pass.
The counter 5 includes a contact point 14 that allows ΔxU or Δxd to pass through, and a counter 5 that outputs an output x using ΔxU or Δxd as an input signal. Next, the operation of such a motor speed setting device will be explained.

When the acceleration command UP is issued and the contact 13 is turned on, ΔxU is added to the counter 15 every sampling time Δ7, and the counter 5 increases the output x. On the other hand, deceleration command DO
When WN is output and contact 14 is turned on, △xd is subtracted from counter 15 every sampling time △7, and counter 1
5 decreases the output x. At this time, △xU has an output x of 0
The new formula △XU=ki△7 can be obtained from the time tU increasing from xU to the sampling time M. Similarly, Δxd is determined by the arithmetic expression Δxd=harm M from the time td during which the output x decreases from xd to 0 and the sampling time Δ7.

FIG. 2 shows how the counter output x increases and decreases with respect to time t.

Since the conventional device is configured as described above, △x
When calculating U or △ or d using the circuit 11 or 12, a digit loss may occur depending on the set values of the parameters xU, tU, △7 or xd, td, △7, and this digit loss is the output x.
There was a drawback that the errors accumulated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor speed setting device that can prevent the accumulation of precision errors and increase or decrease the output with high accuracy at any rate of increase or decrease.

Hereinafter, specific examples of the present invention will be explained in detail with reference to FIGS. 3 to 5. The motor speed setting device of this embodiment has a sampling time common? Based on the time counting counter tortoise that adds △ at each time and the time signal t given from this counter 1, an acceleration pattern function x=f(t
), and a deceleration pattern function block 2 that calculates the deceleration pattern function x=g(t) as shown in FIG. 5 based on the time signal t given from the counter 1. 3 and "turns on during acceleration and blocks 2.
A contact 6 passes the output x=f(x) of the block 3, a contact 7 turns on during deceleration and passes the output x=g(t) of the block 3, and the output x given through the contact 6 and A counter 1 for counting time at the start of acceleration based on the output x given through the output holding memory 0 and the memory 0.
An acceleration pattern inverse function block 4 performs an inverse operation t=f-1(x) on the acceleration pattern function block 2 in order to obtain the initial value tP of A deceleration pattern inverse function block 5 performs an inverse operation t=g-1(x) on the deceleration pattern function block 3 in order to obtain the initial tP of the time counting counter, and a deceleration pattern inverse function block 5 that is turned on by the acceleration start command and operates the time counting counter. It is comprised of a contact 8 that presets the time tP signal, which is an initial value, in the counter 1, and a contact 9 that is turned on in response to a deceleration start command and presets the time tp signal in the counter 1. Next, the operation of this device will be explained.

When the acceleration signal is input, the acceleration pattern inverse function block 4 performs an inverse calculation t=f-1(x) from the previous device output x.
The corresponding time tP is obtained, and this time tP is preset in the time counter 1 via the contact 8. The time counter 1 takes the time tP as an initial value and adds Δt to the sampling time Δ7. An acceleration pattern x=f(t) is obtained from the value t in the acceleration pattern function block 2, and the output x is stored in the output holding memory amount 0. Even when a deceleration signal is input, the output x is obtained in the same manner as above. In addition, although the output holding memory 10 was used in the above embodiment, the memory IQ is omitted and the function block 2,
The calculation result of step 3 may be directly output.

Further, in the above embodiment, f(x) and g(x) are described as linear functions, but any linear functions may be used within the required range. Furthermore, in the above embodiment, the case of a motor speed setting device was explained, but the above embodiment can also be applied to a control device that outputs an output signal using time as a variable, such as voltage, current, and flow rate adjustment of gas, liquid, etc. Get a similar effect.

As explained above, the motor speed setting device according to the present invention prevents the accumulation of precision errors by directly calculating the output x from the time element t using the function f(t) or g(t).
Any desired addition/subtraction pattern can be obtained with high precision.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional device, FIG. 2 is a line diagram showing increases and decreases in the counter output x with respect to time t, and FIG. The figure and Fig. 5 are diagrams showing acceleration patterns and deceleration patterns. 1... Counter for time counting, 2... Acceleration pattern function block, 3... Deceleration pattern function block. , 4...Acceleration pattern inverse function block, 5
... Deceleration pattern inverse function block. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 An acceleration pattern inverse function block that calculates the corresponding time t_p by performing an inverse calculation from the device output x during acceleration, and a corresponding time t_p by performing the inverse calculation from the device output x during deceleration.
a deceleration pattern inverse function block for determining the deceleration pattern, a time counter that presets the time t_p given from each of the blocks and adds Δτ for each sampling time Δτ;
The acceleration pattern function x is determined by the count value t of the counter.
An acceleration pattern function block that outputs =f(t) and a deceleration pattern function x =
It is equipped with a deceleration pattern function block that outputs g(t) and an output holding memory that stores the device output A motor speed setting device characterized by being able to output a deceleration pattern.