JPS62129718A - Temperature compensated resolver type clinometer - Google Patents

Abstract

PURPOSE:To improve absolute accuracy of rotating angle position detection at reduced temperature drift, by connecting in series electric resistances between the secondary winding of resolver and one side of a signal wire. CONSTITUTION:A detecting unit 118 is composed of filter, wave-forming circuit, etc. Further, in a signal processing unit 119, a signal V0' is received as a feedback signal corresponding to an operation condition of a rotation-available unit 112 and a controlling signal, etc. for the unit 112 is formed. In this case, a phase characteristic of output voltage does not depend on the secondary winding resistance, but on a compensating resistance RS. In the conventional method, in case when the resistance RS is not existing, a phase fluctuation by the resolver temperature was 3.0 deg. covering 0 deg.C-100 deg.C, however, this value was improved to 1.0 deg. in this case. Further, as it is assured that a phase drift is of approximately 0.8 deg. on the exciting winding side, the rate of improvement on the secondary winding side is from 2.2 deg. to 0.2 deg., resulting to a significant improvement of the phase characteristic.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an angle indexing position detection device using a resolver, and particularly to a resolver-type rotation angle detection device configured to reduce phase changes in an output signal due to temperature changes in the resolver. Regarding equipment.

[Prior art]

A conventional rotation angle detection device using a resolver, as shown in FIG. It consists of a signal line 14 and a control device 15 connected to the other end of the signal line 14.

FIG. 2+al is a diagram for explaining the signal formation state of the resolver 13 of the two-phase excitation and one-phase output side, and in the same figure, the primary winding 13
Excitation signals E cos ωt and Es1 are applied to A and 13B, respectively.
nωt is given, and the secondary winding 13C is given VH-Esi
i(ωL+θ) is induced. Here, the angle of view θ is
It represents the angle by which the rotor axis AX of the resolver 13 rotates from the reference angular position. In this case, the rotor axis AX is attached to the rotary movable part, and thus corresponds to the rotational angular position of the rotary movable part.

FIG. 2 (bl is the output equivalent circuit of the resolver 13,
The reference symbol is the inductance of the secondary winding, Rr is the winding resistance of the secondary cotton, and RL is the load resistance. Output voltage■. is expressed by the following equation.

Further, the phase characteristic is expressed by the following equation.

Therefore, if RL-e css is used, that is, no load, the A characteristic becomes flat, and the human power ■1 and the output V.

The phase difference is O. Here, ω indicates the excitation angular frequency of the resolver 13.

[Problems with conventional technology]

In the arrangement shown in Fig. 2, if the resolver 13 is used in an unloaded state, the temperature drift of the output signal V0 due to the secondary winding will not be a problem, but in reality, as shown in Fig. 1. A signal line 14 is interposed therebetween, and its distributed capacitance acts as a load, causing a temperature drift in the phase of the output signal. The cause of this can be cited as a temperature change in the secondary winding resistance. That is, since the resolver 13 is attached particularly near a rotating movable part (usually directly connected to a motor shaft) of the mechanical device 1), the temperature changes greatly depending on its movable state. Note that the temperature drift of the winding resistance is uniquely determined from the temperature coefficient of the copper wire.

Figure 2 FC+ is the resolver output equivalent circuit when considering the signal line (cable) 14 in Figure 1, L is the inductance of the secondary winding, R is the secondary winding resistance, and C is the cable or signal This is the distributed capacity of m14. The output voltage V0 is expressed by the following equation.

■ Further, the positional characteristic of equation (3) is expressed by the following equation.

As is clear from reference 2 (4), even if the resolver output signal is received without load as long as the distributed capacitance of the signal line 14 exists, the resistance value R changes due to temperature changes in the resolver secondary winding resistance. , the phase of the output V0 changes. That is, a temperature drift in phase occurs. Moreover,
In a normal layout, the length of the signal line 14 varies from several meters to several tens of meters, and the value of the distributed capacitance C also varies.

[Purpose of the invention]

In the present invention, in the presence of the distributed capacitance C of the signal line itself, the zero characteristic of the output signal changes due to temperature changes in the secondary winding, and in particular, in a resolver, the phase angle is inherently detected. This is intended to solve the problem that it is undesirable for the phase characteristics of the output to be influenced by factors other than the amount of rotation of the rotary movable part because the function of the rotary movable part is utilized. In other words, the purpose is to reduce the temperature drift related to this phase and improve the absolute accuracy of rotational angle position detection, so that the temperature drift countermeasures that were conventionally taken are on the load side (control device side). However, the present invention is characterized in that it is performed on the secondary winding side.

[Summary of the invention]

The present invention employs a two-phase excitation, one-phase output method, in which a series resistor is connected close to the secondary winding output side of a resolver attached to a rotating movable part in a mechanical device, and a signal line is connected in series with the resistor. The present invention provides a resolver rotation angle detection device in which a control device is connected to the other end of the signal.

[Embodiment of the Invention] FIG. 3 is a diagram showing the layout of an apparatus according to an embodiment of the present invention. In the figure, reference numerals 1) 1.1) 2.1) 3 correspond to the mechanical device 1) and rotary movable part 12) resolver 13 shown in FIG. 1, and reference numerals 1) and 6 correspond to the resolver 1). A temperature compensation resistor (R3) is connected in series with the signal line 1) 4 near the output end of the secondary winding No. 3. Reference number 1)
Reference numeral 5 denotes a control device, which includes a load resistor 1) 7 for extracting the output signal Vo', that is, power, a detecting section 1) 8 for amplifying the signal Vo', and the detecting section 1.
) 8; The detection section 1) 8 consists of a filter, a waveform shaping circuit, etc. In addition, the signal processing unit 1) 9 outputs a signal Vo as a feed signal corresponding to the operating status of the rotary movable unit 1) 2.
' is used to form control signals etc. for the rotary movable part 1)2.

FIG. 4 is an equivalent circuit of the resolver output including the temperature compensation resistor shown in FIG. In the same figure, the phase temporality l of the output Vo'
V O' is given by the following equation.

ωC(Rr-1-R5) In equation (5), if R,<Rs (for example, 25
゛At C, R, = 170 (Ω), R, -5 (KΩ)
) holds true. The temperature coefficient of R is approximately 4300
ppm/”C, so the temperature coefficient of resistor R5 is ±25
When expressed as ppm/'c, as is clear from equation (6),
The phase characteristic of the output voltage does not depend on the secondary Wg resistance R, but is determined by the compensation resistance Rs.

Also, in order to avoid sharpening the resonance point in the circuit shown in FIG. 4, the coefficient is set to be smaller.

Now, let ζ-1, R, -170 (Ω), L = 50
CmH)Cm0.01CμF], then R, = 4.3
CKΩ]. (The reason for setting ζ-1 is to prevent the phase characteristics from becoming steep at the resonance point.) In the actual example, R5-5 (KΩ), RL-1,5 [K
Ω] and the excitation frequency ω/2 rc-5CKtlz), the output voltage Vo' was 0.75 (V) to 0.7 CV] when the signal line 1)4 was in the range of 3 m to 30 m.

〔Effect of the invention〕

In the conventional method, if there is no temperature compensation resistor Rs, the signal &
The phase change due to resolver temperature at 'A 3 m was 3.0 degrees from 0°C to 100°C, but this was improved to 1.0 degrees in the example to which the present invention was applied. In this case, it has been confirmed that there is a phase drift of 0.8 degrees on the excitation winding side, so the government ratio on the secondary winding side is 2.2 degrees (3,0
(excluding 0.8 degrees from degrees) to 0.2 degrees (1,0 degrees to 0
．． 8 degrees), and the effect of making it possible to significantly improve the phase characteristics was obtained.

Note that the excitation frequency of the resolver is usually several KHz (including the case of a rectangular wave), and a resonant circuit is formed by the distributed capacitance C of the signal line and the inductance L of the resolver. In particular, a method is used to extract the fundamental wave by making the excitation frequency and the resonant frequency of the resonant circuit completely different, but in this case,
If the resonance point is made sharper, the change in phase characteristics with respect to temperature will also increase, so it is preferable to shift the resonance point when selecting the compensation resistance value.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the layout of a conventional resolver type angle detection device. Figure 2 ta+ is a configuration diagram of a resolver with two-phase excitation and one-phase output. Figure 2 tb+ is an equivalent circuit diagram of a conventional resolver output. , FIG. 2(C) is a resolver output equivalent circuit diagram in consideration of the distributed capacitance of the signal line in the conventional system, FIG. 3 is a diagram explaining the layout in the embodiment of the present invention, and FIG. It is an output equivalent circuit diagram. 1) 1... Mechanical device 1) 2... Rotating movable part 1) 4... Signal line 1) 5... Control device 1) 6... Temperature compensation resistance patent applicant Toshiba Machine Co., Ltd. Top Toei Electric Co., Ltd. "lG1 1') F I G, 2a L Rr FIG, 2c L Rr

Claims (2)

[Claims] (1) A resolver that is attached to a mechanical device and detects the rotational angular position of a rotating movable part in the device using a two-phase excitation, one-phase output method, and one end of which is connected to the secondary winding of the resolver. In the resolver type angle detection device comprising a signal line and a control device connected to the other end side of the signal line and forming an electric signal corresponding to the rotational angular position of the movable part from the detected one-phase output signal, An electric resistance is connected in series between the secondary winding of the resolver and one end of the signal line, and detection on the control device side is caused by the temperature change of the resolver and due to the influence of the distributed capacitance of the signal line. A temperature-compensated resolver type angle detection device characterized by being configured to reduce signal phase changes. (2) A temperature-compensated resolver-type angle detection device using a precision resistor as the temperature-compensating resistor in the device according to claim 1.