JPH04329305A - Bent angle detector - Google Patents

Abstract

PURPOSE:To reduce a temperature drift by detecting bent angle of a base member based on a resistance change in the first to forth patterns which are provided on the base member, and forming the first to forth patterns from resistors made of identical material so as to set roughtly uniform resistance temperature coefficients. CONSTITUTION:This bent angle detector is provided with a flexible base member 13 whose sectional shape is uniform in its longitudinal direction and bent angle detecting means which forms the first and second patterns P1, P2 laid on the upper surface side of the base member 13, and the third and forth patterns P3, P4 laid on the lower surface side, consitutes a bridge circuit from flexible resistors 14a-14d whose resistances change according to the bend of the base member 13 and the first to forth patterns P1-P4, detects the resistance changes of the first to forth patterns P1-P4 and generates signals corresponding to the bent angle of the base member 13. The bent angle of the base member 13 is detected based on the resistance changes of the first to forth patterns P1-P4, and the first to forth patterns P1-P4 are formed from resistor which are made of an identical meterial, so that the resistance temperature coefficients may become roughtly uniform, and a temperature drift may be reudced.

Description

[Detailed description of the invention] [Industrial application field]

[0001] This invention applies, for example, to human fingers, wrists,
The present invention relates to a bending angle detection device that can detect the bending angle of a joint in each limb such as an elbow.

0002

[Prior Art] As is well known, in natural musical instruments, musical tones are generally formed by playing the strings or keyboard, or by blowing a pipe. Musical sounds are generated by this.

By the way, if it becomes possible to generate musical tones based on natural human movements, the performance operation will be different from the feeling of playing conventional musical instruments, and new performance enjoyment and new performance effects will be created. can play. For example, bending movements of fingers, wrists, elbows, shoulders, etc. are natural daily movements and are often used in choreography for dances and the like. Therefore, if musical tones can be controlled based on these movements, it becomes possible to control musical tones according to dances that incorporate these movements or bending movements. Therefore, from this perspective, the present applicant has departed from the concept of playing and has proposed an electronic musical instrument that controls musical tones in accordance with the bending of a person's hands and feet.

As described above, this type of electronic musical instrument uses a bending angle detection device for detecting the bending angle of a human hand or foot. An example of the configuration of this bending angle detection device will be described below with reference to FIGS. 7 to 11. First, FIGS. 7 and 8 are diagrams showing an example of an angle detection device used for detecting the bending angle of the joints of fingers among the above-mentioned bending movements. In these figures, reference numeral 10 denotes a glove-like wearing device sewn from stretchable fabric and worn on each finger. Reference numeral 12 denotes a detection element that is housed so as to come into contact with the back surface of each finger (thumb to little finger) of this mounting tool 10.

FIG. 9 is a diagram showing an example of the configuration of this detection element 12. In this figure, reference numeral 13 denotes a base member in the form of a long thin plate having sufficient insulation and flexibility. U-shaped resistors 14a are provided on the upper and lower surfaces of the base member 13.
, 14b are installed respectively. These resistors 14
Lead wires 15a to 15a are connected to the connection terminals at each end of a and 14b.
15d are connected to each other. Such a resistor 14a
, 14b are made of a flexible element material (for example, carbon powder) whose electrical resistance value changes according to expansion and contraction. As a result, the base member 13 is
When it is bent from the state shown in FIG. 0 (a) to the state shown in FIG. . Due to these properties, the resistance change of the resistors 14a and 14b that occurs depending on the bending angle of the base member 13 is
It is detected by the detection circuit shown in 1.

In FIG. 10, 16 is a resistor 14a, 1
This is a well-known bridge connection circuit that converts a change in the resistance value of 4b into a level. This bridge connection circuit 16 includes a resistor R1
and resistor R2, each one end of which is connected to a voltage +V to a power supply, and the other end of each of which is connected to one end of each of resistors 14a and 14b,
Further, the other ends of the resistors 14a and 14b are grounded. Then, the connection point P between this resistor R1 and the resistor 14a
A and the connection point Pb between the resistor R2 and the resistor 14b are detected by the differential amplifier 18. The output signal of the differential amplifier 18 is outputted from the output terminal Tout as a detection signal Vs corresponding to the bending angle of the base member 13.

[0007]

By the way, in the conventional bending angle detection device described above, the resistors R1 and R2 constituting the bridge connection circuit 16 are provided on the detection circuit side, and these resistors R1 and R2 are Almost equal temperature coefficient a
have. On the other hand, the resistors 14a and 14b constituting this bridge connection circuit 16 are laid on both sides of the base member 13 mentioned above, and are not made of the same material as the resistors R1 and R2. It has a temperature coefficient b that is different from the temperature coefficient a.

Therefore, when the bridge connection circuit 16 is constructed using resistors having different temperature coefficients, the differential amplifier 1 connected to the rear stage of the bridge connection circuit 16
8, a temperature drift occurs according to the difference between the temperature coefficients a and b described above, and the output of the differential amplifier 18 becomes unstable due to the temperature change of the bridge connection circuit 16, and is controlled by the output of the bridge connection circuit 16. There is a problem in that it leads to malfunction of equipment, etc. Moreover, in this case, the resistor R1
, R2 and the resistors 14a, 14b have different temperature coefficients, making it difficult to perform temperature compensation. The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a bending angle detection device in which temperature drift is extremely reduced even without temperature compensation.

[0009]

[Means for Solving the Problems] The present invention provides a base member having a uniform cross-sectional shape in the longitudinal direction and having flexibility;
pattern, and a third pattern laid on the bottom side of the base member.
and a fourth pattern, a flexible resistor whose resistance changes according to the bending of the base member, and the first to fourth patterns constitute a bridge circuit, and the first to fourth patterns constitute a bridge circuit.
- bending angle detection means for detecting the resistance change of the fourth pattern and generating a signal corresponding to the bending angle of the base member.

0010

According to the above structure, the bending angle of the base member is detected based on the resistance changes of the first to fourth patterns provided on the base member. Here, since the first to fourth patterns are formed of resistors made of the same material, their resistance temperature coefficients are substantially uniform, and as a result, temperature drift is reduced.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. a. First Embodiment FIGS. 1A and 1B are a perspective view and a sectional view showing the structure of a detection element 12 according to a first embodiment of the present invention. In this figure, parts corresponding to those in FIG. 12 are given the same numbers, and their explanations will be omitted. This figure is Figure 12
The difference from that shown in FIG. 1 is that U-shaped resistors 14a and 14b are provided on the upper surface of the base member 13, and U-shaped resistors 14c and 14d are provided on the lower surface. Here, the U-shaped resistor 14a forms a pattern P1 with a uniform width along the longitudinal direction of the base member 13, and similarly, the resistors 14b to 14d each have a uniform width along the longitudinal direction. Patterns P2 to P4 are formed. and,
Connection terminals are provided at the base ends of these patterns P1 to P4, and lead wires 15a to 15 are provided to each of these connection terminals, respectively.
5h is connected. Note that the detection element 12 having the above configuration is not limited to that shown in FIG.
For example, as shown in FIG. 2, the thickness of the base member 13 does not need to be uniform, and furthermore,
4 may each have an arbitrary pattern width.

The resistance changes of the resistors 14a to 14d that occur depending on the bending angle of the base member 13 are detected by a detection circuit shown in FIG. This figure differs from that shown in FIG. 11 in that patterns P1 to P4 formed by resistors 14a to 14d constitute a bridge connection circuit 16. Here, the bridge connection circuit 16 connects one end of each of the patterns P1 and P4 to the power supply voltage +V, and
Each other end is connected to one end of each of the patterns P3 and P2, and each other end of the patterns P3 and P2 is grounded. Then, the connection point Pa between this pattern P1 and pattern P3
The voltage between the connection point Pb of the pattern P4 and the pattern P2 is detected by the differential amplifier 18, and the output voltage of the differential amplifier 18 is outputted to the output terminal Tout as a detection voltage Vs corresponding to the bending angle of the base member 13. is output from. Note that this differential amplifier 18 has a well-known configuration including an operational amplifier 17, resistors R3 to R7, and variable resistors VR1 and VR2. Here, the variable resistor VR1 is for offset gain adjustment, and the resistor 14 forming the pattern P1
Detected when the ratio of the resistance value of a and the resistance value of the resistor 14c forming the pattern P3 is equal to the ratio of the resistance value of the resistor 14b forming the pattern P2 and the resistance value of the resistor 14d forming the pattern P4. The voltage Vs is adjusted to be "0". Further, the variable resistor VR2 is for gain adjustment, and is for adjusting the output level of the detection voltage Vs.

According to such a configuration, patterns P1 to
Since the resistors 14a to 14d forming P4 are made of the same material, each pattern P forming the bridge connection circuit 16
The resistance temperature coefficients of 1 to P4 have substantially the same value. As a result, the temperature drift that conventionally occurs due to differences in temperature coefficients is significantly reduced. Further, in the above configuration, the patterns P1 and P formed on the base member 13
When bending is applied so that 2 is on the inside, a larger voltage change can be obtained compared to the conventional bridge connection circuit 16 (see FIG. 11). As a result, the signal-to-noise ratio of the signal for detecting the bending angle is improved.

b. Second Embodiment Next, a second embodiment of the present invention will be described. The resistance value of the detection element 12 according to the first embodiment described above also changes when the base member 13 is twisted in the longitudinal direction. Therefore, if twisting and bending are applied at the same time, there is a risk that an error will occur in the bending angle detection since resistance changes corresponding to the twisting will also be included. Therefore, the configuration of the detection element 12 that does not cause a change in resistance even when such twisting is applied will be described below with reference to FIG. 4.

First, FIG. 4A is a sectional view showing the configuration of the detection element 12, and the cross mark in the figure represents the center of twist when the base member 13 is twisted along the longitudinal direction. The difference between this figure and the one shown in FIG. 1(A) is that patterns P1 and P4 (or patterns P1 and P2) have the same pattern width and are formed at points symmetrical positions with respect to the center of twist. That's true. The patterns P1 to P4 thus arranged on the base member 13 are shown in FIG.
The bridge is assembled as shown.

According to such a configuration, the base member 13
Even if a twist is applied in the longitudinal direction of the pattern P1 and P4, the resistance change due to this twist is
2 and pattern P3. and,
Since this resistance change is canceled out by the bridge connection circuit 16, only the bending angle will be detected. Note that this applies to all patterns P1 to P4 as shown in FIG.
may be formed to have the same pattern width, and the resistors 14a to 14d may have the same resistance value.

c. Modified Example In the second embodiment, the torsion center of the base member 13 is fixed at one location, and each of the patterns P1 to P4 is provided at a point symmetrical with respect to this torsion center. However, in reality, the twist center position is not determined and the position may change somewhat. Therefore, even if the torsion center position changes as shown in FIG. 6A, for example, A, B, C, it is necessary to cancel the influence of this torsion. Here, the configuration of the detection element 12 that can offset the resistance change due to twisting even in such a case will be described with reference to FIG.

This figure differs from the one shown in FIG. 1(a) in that the pattern formed on the upper surface side of the base member 13 and the pattern formed on the lower surface side correspond to each other. be. That is, the pattern P1 and the pattern P3 are arranged so that the front and back sides correspond to each other, and the pattern P2 and the pattern P4 are arranged so that the front and back sides correspond to each other. The patterns P1 to P4 arranged on the base member 13 in this manner are assembled into bridges as shown in FIG. 6(b). In such a configuration, even if the twist center position changes, the effect appears in the same way on pattern P1 and pattern P3, or pattern P2 and pattern P4, so it is possible to cancel out the resistance change due to such twist. can.

[0019]

As described above, according to the present invention, the bending angle of the base member is detected based on the resistance changes of the first to fourth patterns provided on the base member. Here, since the first to fourth patterns are formed of resistors made of the same material and have substantially uniform resistance temperature coefficients, temperature drift can be extremely reduced without temperature compensation.

[Brief explanation of drawings]

FIG. 1 is a perspective view and a sectional view showing the configuration of a first embodiment of the present invention.

FIG. 2 is a sectional view showing another example of the first embodiment.

FIG. 3 is a circuit diagram showing the configuration of a detection circuit in the first embodiment.

FIG. 4 is a cross-sectional view showing the configuration of the detection element 12 in the second embodiment, and a diagram showing a connection example of the bridge connection circuit 16.

FIG. 5 is a sectional view showing another example of the second embodiment.

FIG. 6 is a diagram for explaining a modified example.

FIG. 7 is a diagram for explaining a conventional example.

FIG. 8 is a diagram for explaining a conventional example.

FIG. 9 is a diagram for explaining a conventional example.

FIG. 10 is a diagram for explaining a conventional example.

FIG. 11 is a diagram for explaining a conventional example.

[Explanation of symbols] 12...Detection element, 13...Frame member, 14a to 14d
...Resistor, P1 to P4... Patterns (first to fourth patterns), 16... Bridge connection circuit, 18... Differential amplifier.

Claims (1)

[Claims] Claim 1: The cross-sectional shape is uniform in the longitudinal direction,
forming a flexible base member, first and second patterns laid on the upper side of the base member, and third and fourth patterns laid on the lower side of the base member, A bridge circuit is constituted by a flexible resistor whose resistance changes according to the bending of the base member and the first to fourth patterns, and the resistance change of the first to fourth patterns is detected to detect the resistance change of the first to fourth patterns. 1. A bending angle detection device comprising: bending angle detection means for generating a signal corresponding to a bending angle of a base member.