JPH062139U - Interface device for magnetic resolver - Google Patents

Abstract

(57) [Abstract] [Purpose] Corrects changes in delay time that occur in the excitation signal transmission path and output signal transmission path of a phase modulation type magnetic resolver, and is not affected by aging of the circuit or replacement of the servo driver. An object is to realize an interface device of a magnetic resolver capable of detecting an absolute angle. [Structure] The same excitation signal is transmitted to the excitation signal transmission path of the excitation circuit and the output signal transmission path of the magnetic resolver, and the phase difference counter measures and measures the difference in delay time that occurs in both transmission paths at this time. Keep the value in the latch. The measured value held in the latch is used to correct the measured value of the phase difference counter in the absolute angle detection operation. Thus, the absolute angle is obtained by correcting the difference between the delay times generated in the transmission path of the excitation signal and the transmission path of the output signal of the phase modulation type magnetic resolver.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of characteristics of an interface device used in a magnetic resolver of a phase modulation type and an absolute type.

[0002]

[Prior art]

 Some magnetic resolvers used for rotation detection of motors are phase modulation type and absolute type. The phase modulation type is a type in which the phase of the output signal of the magnetic resolver is modulated according to the rotation angle of the detection target. The absolute type detects the absolute rotation angle of the detection target.

Conventionally, there has been, for example, a structure shown in FIG. 2 as an interface device of a magnetic resolver of a phase modulation type and an absolute type. In FIG. 2, 1 is a magnetic resolver of a phase modulation type and an absolute type, and 2 is an exciting circuit for exciting a coil of the magnetic resolver 1. The excitation signal of the excitation circuit 2 consists of a two-phase signal of a sin phase signal and a cos phase signal. The excitation signal of the sin phase of the excitation circuit 2 is Esinωt (E is the amplitude, ω is the angular velocity, t is the time), and the output signal of the magnetic resolver 1 is Ksin (ωt + θ) (K is the amplitude and θ is the absolute value of the detection target). Angle). 3 is a comparator for binarizing the sin phase signal of the excitation circuit 2 4 is a band pass filter (hereinafter referred to as BPF) for extracting the signal component of the output signal of the magnetic resolver 2 5 is a signal extracted by the BPF 4 A comparator which binarizes the component, and 6 is a phase difference counter which measures the phase difference between the signals SIG0 and SIG1 which are binarized by the comparators 3 and 4, respectively. The measured value of the phase difference counter 6 becomes the detected value of the absolute angle.

In such an interface device, the signal SIG0 has a delay time T ₁ due to the comparator 3, and the signal SIG1 has a delay time T ₂ due to the BPF ₄ and a delay time T ₃ due to the comparator 5. If the delay time T ₁ is different from the delay time T ₂ + T ₃ , an error occurs in the phase difference between the signals SIG0 and SIG1. Since the interface device of FIG. 2 detects the absolute angle from the phase difference between SIG0 and SIG1, the above-mentioned error appears as a direct detection error. In order to eliminate this error, the apparatus shown in FIG. 2 gives a constant offset to the detected value of the absolute angle.

However, the delay time T ₁ is caused by the change of the circuit over time, especially the change of the characteristics of the capacitor used for the BPF, and the lot variation due to the replacement of the servo driver to which the interface device is connected. Therefore, there is a problem that the delay time T ₂ + T ₃ changes and an error occurs in the detected value of the absolute angle.

[0006]

[Problems to be solved by the device]

 The present invention has been made to solve the above-mentioned problems, and corrects the change in delay time generated in the transmission path of the excitation signal and the transmission path of the output signal of the phase modulation type magnetic resolver to correct the aging of the circuit. The objective is to realize a magnetic resolver interface device that can detect the absolute angle that is not affected by changes or replacement of the servo driver.

[0007]

[Means for Solving the Problems]

 The present invention provides an exciting circuit for exciting a coil of a phase-modulation type and absolute type magnetic resolver, a first comparator for binarizing an exciting signal of the exciting circuit, and a signal of an output signal of the magnetic resolver. A filter for extracting the component, a second comparator for binarizing the signal component extracted by this filter, and a phase difference between the binarized signals by the first and second comparators, respectively. In a magnetic resolver interface device having a phase difference counter for obtaining an absolute position, a switch connecting an input end of the filter to an output end of the excitation circuit or an output end of the magnetic resolver, and a measured value of the phase difference counter. A latch for holding and outputting, a subtractor for subtracting the measured value of the phase difference counter and the output value of the latch, the switch, Controlling means for controlling the latch; and the controlling means, when the switch is connected to the output end side of the exciting circuit, the exciting signal passing through the first comparator, the filter and the second When the phase difference of the excitation signal passed through the comparator is measured by the phase difference counter, the measured value is held in the latch, and when the switch is connected to the output end side of the magnetic resolver, the first comparator is turned on. The phase difference between the excitation signal that passed and the output signal of the magnetic resolver that passed through the filter and the second comparator was measured by the phase difference counter, and the measured value held by the latch was output. The interface device of the magnetic resolver characterized in that the subtractor subtracts the output value of the latch from the measured value of the phase difference counter to calculate the corrected absolute position. It is a place.

[0008]

[Action]

 In this invention, the same excitation signal is transmitted to the transmission path of the excitation signal of the excitation circuit and the transmission path of the output signal of the magnetic resolver, and the difference in delay time generated in both transmission paths at this time is detected by the phase difference counter. Measure with and hold the measured value in the latch. The measured value held in the latch is used to correct the measured value of the phase difference counter in the absolute angle detection operation. As a result, the absolute angle is obtained by correcting the difference between the delay times generated in the transmission path of the excitation signal and the transmission path of the output signal of the phase modulation type magnetic resolver.

[0009]

【Example】

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. 1 that are the same as those in FIG. 2 are given the same symbols. In FIG. 1, a switch 7 is a relay in this embodiment. The relay 7 connects the input end of the BPF 4 to the output end a ₁ of the excitation circuit 2 or the output end a ₂ of the magnetic resolver 1. 8 is a latch that holds and outputs the measured value of the phase difference counter 6, 9 is a subtractor that subtracts the measured value of the phase difference counter 6 and the output value of the latch 8, and 10 is the switching of the relay 7 and the latch 8 Is a control means for controlling the latch timing of.

The operation of such an interface device will be described. Delay times by the comparator 3, the BPF 4, and the comparator 5 are set to T ₁ , T ₂ , and T ₃ , respectively. Further, the true phase difference between the output signal of the magnetic resolver 1 and the sin phase signal of the excitation circuit 2 is t. When the relay 7 is connected to the contact a ₁ side, the measured value Δ ₁ of the phase difference counter 6 is given by the following equation. Δ ₁ = T ₂ + T ₃ −T _{1 When the} relay 7 is connected to the contact a ₂ side, the measured value Δ ₂ of the phase difference counter 6 is as follows. Δ ₂ = t + T ₂ + T ₃ −T _{1 When the} relay 7 is connected to the contact a ₁ side, the control means 10 causes the latch 8 to latch the measured value Δ ₁ , and then the relay 7 is connected to the contact a ₂ side. By doing so, the output Δ ₃ of the subtractor 9 is given by the following equation. Δ ₃ = Δ ₂ −Δ ₁ = t + T ₂ + T ₃ −T ₁ − (T ₂ + T ₃ −T ₁ ) = t As a result, the delay times T _{1 to} T ₃ due to the comparators 3 and 5 and the BPF ₄ are canceled, The true phase difference t is obtained.

[0011]

[Effect of device]

 According to the present invention, the difference between the delay time generated in the transmission path of the excitation signal of the magnetic resolver and the delay time generated in the transmission path of the output signal of the magnetic resolver is measured, and the measured value is used to determine the absolute angle detection value. Correcting. As a result, it becomes possible to detect the absolute angle in a phase modulation type magnetic resolver without being affected by aging of the circuit or replacement of the servo driver.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a conventional interface device of a magnetic resolver.

[Explanation of symbols]

 1 Magnetic Resolver 2 Excitation Circuit 3, 5 Comparator 4 BPF 6 Phase Difference Counter 7 Relay 8 Latch 9 Subtractor 10 Control Means

Claims (1)

[Scope of utility model registration request] 1. An exciting circuit for exciting a coil of a magnetic resolver of a phase modulation type and an absolute type, a first comparator for binarizing an exciting signal of the exciting circuit, and an output signal of the magnetic resolver. A filter for extracting a signal component, a second comparator for binarizing the signal component extracted by this filter, and a detection target by measuring the phase difference between the binarized signals by the first and second comparators, respectively. In a magnetic resolver interface device having a phase difference counter for obtaining the absolute position of the switch, a switch connecting the input end of the filter to the output end of the excitation circuit or the output end of the magnetic resolver, and the measurement of the phase difference counter A latch that holds and outputs a value, a subtractor that subtracts the measured value of the phase difference counter from the output value of the latch, and the switch, Control means for controlling the latch, and the control means, when the switch is connected to the output end side of the excitation circuit,
The phase difference between the excitation signal passing through the first comparator and the excitation signal passing through the filter and the second comparator is measured by the phase difference counter, the measured value is held in the latch, and the switch is connected to the magnetic resolver. When connected to the output end side of the, the phase difference between the excitation signal passed through the first comparator and the output signal of the magnetic resolver passed through the filter and the second comparator is measured by the phase difference counter, and An interface of a magnetic resolver characterized in that the latch outputs the held measurement value, and the subtractor subtracts the output value of the latch from the measurement value of the phase difference counter to calculate a corrected absolute position. apparatus.