JPS63222268A - Rotational speed detector - Google Patents

Abstract

PURPOSE:To enable highly accurate detection, by determining a digital value representing the angle of rotation from outputs of two windings of a resolver to detect a rotational speed based on a difference of the digital values and a sampling time. CONSTITUTION:A resolver 1 is coupled to a rotor intended to detect rotational speed and an angle of rotation-digital converter 3 converts an angle of rotation into a digital value based on an output of the resolver 1 varying with the rotation to output. A CPU 4 samples the output and computes the rotational speed of the rotor based on a deviation between the preceding sample value and the current sample value and a sampling cycle. A rotational speed data is stored into a memory 5 and then, applied to a sequencer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotational speed detection device suitable for, for example, a sequencer system.

[Prior Art] This type of conventional rotational speed detection device includes, for example, a rotary encoder coupled to a rotating body whose rotational speed is to be detected, and the output of this rotary encoder is input to a counter device to calculate the counted value. There was one that processed this using a sequence program. This was highly practical in that by simply adding a rotary encoder as hardware, various controls corresponding to the speed of the rotating body could be performed.

[Problems to be Solved by the Invention] With the conventional rotational speed detection device described above, fairly accurate measurements can be made by fixing the scan time of the sequence program, but in the sequencer system, the scan time can be changed. There is a problem in that the measurement accuracy depends on this scan time, and it is not possible to detect the rotational speed with high precision in practice.

This invention was made to solve the above problems, and the purpose is to obtain a rotation speed detection device that can detect rotation speed with high accuracy without being affected by the scan time of a sequencer system, etc. shall be.

[Means for Solving the Problems] In the present invention, a resolver is coupled to a rotating body whose rotational speed is to be detected, and a rotation angle/digital converter adjusts the rotation angle based on the output of the resolver that changes in accordance with the rotation. The calculation means samples this output and calculates the rotational speed of the rotating body based on the deviation between the previous sampling value and the current sampling value and the sampling period. It is composed of

[Operation] This invention utilizes the property of a resolver that the coupling ratio of two windings changes depending on the rotation angle of the rotor, and calculates a digital value corresponding to the rotation angle from the output of these two windings. Since the rotational speed is detected based on the difference between two digital values obtained by sampling and the sampling time, it is possible to detect the rotational speed with high precision without being affected by the scan time of the sequencer.

Embodiment FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, in which (1) is a resolver in which a rotor is coupled to a rotating body (not shown), (2) is a detection unit, and (3) is a resolver having a rotor coupled to a rotating body (not shown). ) is a rotation angle/digital converter (hereinafter referred to as R/D converter) that inputs the output signals of the two windings of the resolver (1), converts it into a digital value corresponding to the rotation angle of the rotor, and outputs it.
4) is a CPU as a calculation means that samples the output of the R/D converter (3) at regular intervals and calculates the rotation speed from the amount of change in the data, and (5) is ll:PU (
(4) is a memory that stores the data necessary for the calculation and the rotational speed data obtained by the calculation; (6) is the memory (
5) is a sequencer that reads the rotational speed data and performs speed-related sequence control.

The operation of this embodiment will be explained below with reference to the flowchart of FIG.

First, the resolver (1) has a stator called a stator,
A rotor called a rotor is installed coaxially within the case. Both the stator and the rotor are appropriately wound with wires, and the two windings have a structure in which the coupling ratio changes depending on the rotational position of the rotor. Since this change in coupling rate is a function of the rotation angle of the rotor, the R/D converter (3) determines the rotation angle from this relationship, and also
It is converted into a digital value that increases as the rotation angle increases and outputs it. CP[] (4) executes the process shown in the flowchart in FIG. 2 at regular intervals, but in step 101, the digital value output from the R/D converter (3) is converted into the current value. The value is saved in the register of the read memory (5), and in step 102, the previous digital value is taken out from the register, and then,
In step 103, the previous digital value is subtracted from the current digital value, and the rotational speed is calculated from the difference and the sampling time difference and stored in the memory (5).

On the other hand, the sequencer (6) reads the rotational speed data from the memory (5) and performs sequence control related to the rotational speed.

In this case, since the rotation speed is calculated by another CPU (4) other than the CPU that constitutes the sequencer (6), highly accurate rotation speed detection is possible without being affected by the scan time of the sequencer (6). It becomes possible.

In addition, in this embodiment, an R/D converter (3) and a CPU (4) are used.
) and memory (5) as the detection unit (2), it is possible to easily execute control related to the speed of the rotating body just by preparing the resolver (1) and the detection unit (2). However, even with other configurations, the essential points are an R/D converter (3) that converts the output of the resolver into a digital value corresponding to the rotation angle of the rotating body;
Rotation speed detection similar to that described above is provided if the output is sampled and calculation means is provided to calculate the deviation between the previous sampling value and the current sampling value, and the rotation speed of the rotating body based on the sampling period. is possible.

[Effects of the Invention] As explained above, according to the present invention, the rotation angle is determined from the outputs of the two windings of the resolver, the rotation angle is converted into digital values, and two digital values obtained by sampling these rotation angles are obtained. Since the rotational speed is calculated based on the difference between the two and the sampling time, it is possible to detect the rotational speed with high precision without being affected by the sequence scan time or the like.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of the same embodiment. In the figure, (1) is a resolver, (2) is a detection unit, (
3) is an R/D converter, and (4) is a CPII. (5) is memory, (6) is sequencer. Agent: Masuo Oiwa
N) Spontaneous writing of procedural amendments) Showa year, month, day 1, Indication of case: Japanese Patent Application No. 62-55676η2, Name of the invention: Rotation speed detection device 3, Person making the amendment Representative Moriya Shiki 4, Attorney 6, Contents of amendment (1) The scope of claims section of the specification shall be amended as shown in the attached sheet. (2) The statement "deviation in," on page 3, line 8 of the specification, is amended to read "difference in." (3) The statement "stored" on page 5, line 15 of the specification is amended to "stored." 7. List of attached documents A document stating the scope of claims after amendment One or more documents stating the scope of claims after amendment a rotation angle/digital converter that converts the output into a digital value corresponding to the rotation angle of the rotating body; and sampling the output of the rotation angle/digital converter;
The Ω difference between the previous sampling value and the current sampling value,
A rotational speed detection device comprising: and a calculation means for calculating the rotational speed of the rotating body based on a sampling period.

Claims (1)

[Claims] a resolver coupled to a rotating body whose rotational speed is to be detected; a rotation angle/digital converter that converts the output of the resolver into a digital value corresponding to the rotation angle of the rotating body; A rotation speed characterized by comprising a calculation means for sampling the output of the converter and calculating the rotation speed of the rotating body based on the deviation between the previous sampling value and the current sampling value and the sampling period. Detection device.