JPH0488848A - Discriminating device for present condition of switch - Google Patents

Abstract

PURPOSE:To discriminate a currently operating switch accurately by a simple construction even when a plurality of switches operate, by detecting an electrical constant of a resonant circuit group formed by connecting LC series resonant circuits in parallel, and by determining the current states of the switches in a plurality on the basis of a detection output and an output frequency of a variable-frequency power source. CONSTITUTION:When a switch 202 turns to be in an ON state, Vp lowers at the time point when an output frequency of a voltage/frequency converter 23 reaches a resonance frequency of an LC series resonant circuit 262. A microprocessor 29 selects the switch 202 from Vt at the time point of lowering of Vp and outputs a signal corresponding to the switch 202. The output frequency of the voltage/frequency converter 23 is swept herein, and even when all of switches 201, 202,...20N turn to be in ON states, therefore, these ON states can be discriminated by one sweep of frequency. In this case, ON-state signals of a plurality of switches can be transmitted in a multiplex manner only by substantially one signal line.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a method for identifying the current state of a plurality of switches that operate independently of each other, that is, whether they are in an on state or an off state. The present invention relates to a current state identification device.

(Prior Art) As is well known, self-driving cars and robots are equipped with a plurality of tactile sensors in order to achieve appropriate control when they come into contact with obstacles.

There are various types of these tactile sensors, but generally an on/off type switch is used, which turns on or off by contact force when it comes into contact with an obstacle.

By the way, in order to implement appropriate control by mounting a plurality of such on/off type tactile sensors, it is necessary to quickly know which tactile sensor among the plurality of tactile sensors is activated. In this case, if there are a large number of tactile sensors, not only will the system for processing the information be complicated, but there is also a risk of delays in control.

For this reason, conventionally, a device for identifying the current state of a switch as shown in FIG. 4 has been considered.

This identification device uses a voltage division method to speed up information processing. That is, in the figure, 1□, . . . lN1N. 3
．． ...1x indicates the target on/off type tactile sensor. One end side of these tactile sensors is commonly connected to a positive line 2 of a power source. In addition, the other end side of each tactile sensor has a resistance of 3□,...3N, 3N, respectively.
. 1. ... 3x to the negative line (ground) 4 and a capacitor 51. ...5N, 5N
. 1. . . 5X, a diode 6+ of the illustrated polarity, . . . 6N6N+1+ . Both ends of the resistive voltage divider 7 are grounded. Therefore, when the tactile sensor 1 is turned on, a pulse voltage is applied to the anode of the diode 6. By applying this pulse voltage, a current flows in the resistance voltage divider 7 on both sides of the point connected to the diode 6N, which is inversely proportional to the resistance value from the point to the ground point.

Therefore, in this identification device, the voltage drop of the resistors 8a and 8b located at the final stage at both ends of the resistor voltage divider 7 is taken out, and this is applied to the divider 10 via the amplifiers 9a and 9b.
By dividing the position on the resistor voltage divider to which the diode 6N is connected, that is, the tactile sensor I that is turned on
I'm trying to find N. Note that the output of the divider 10 is outputted via the A/D converter 11 in the form of a digital signal. In addition, in the figure, diodes 12□,...12N
.

12N+1...12x1 resistor voltage divider 13, sign inverters 14a, 14b, amplifiers 15a, 15b, divider 1
6. A/D converter 17 indicates a system for identifying a tactile sensor that has been turned off.

However, the conventional identification device configured as described above has the following problems.

That is, in this identification device, the tactile sensor 1°...I
N, IN and 1. ...When 1x is turned on and off one by one, it is possible to accurately identify which tactile sensor is turned on or turned off. However, when two or more tactile sensors are turned on or turned off at the same time, there is a problem in that it is not possible to distinguish between them. In addition, since the identification device configured as described above needs to incorporate a huge number of circuit elements, it not only becomes complicated as a whole, but also has the problem of lacking reliability in operation over a long period of time. there were.

(Problems to be Solved by the Invention) As mentioned above, in the conventional identification device, a plurality of tactile sensors,
In other words, when multiple switches operate at the same time, it is not only impossible to identify them, but the entire system becomes complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a switch current state identification device that can accurately identify which switch is operating even when a plurality of switches are operating, and that has a simple configuration. .

[Structure of the Invention (Means for Solving the Problem) In order to achieve the above object, the current state identification device for a switch according to the present invention is a variable switch whose output frequency changes in a predetermined pattern over time. A frequency power supply and a number of LC series resonant circuits equal to the number of switches having mutually different resonance frequencies are provided, and the LC series resonant circuits are connected in parallel between the output terminals of the variable frequency power supply via the switches one by one in series. a resonant circuit group consisting of a resonant circuit group, a detection means for inspecting an electrical constant of the resonant circuit group, and a determination for determining the current state of the plurality of switches from the output of the detection means and the output frequency of the variable frequency power supply. equipped with the means.

(Function) When a switch connected in series to a certain LC series resonant circuit is in an on state, this LC series resonant circuit resonates when the output frequency of the variable frequency power supply reaches the resonant frequency. When it resonates, the impedance of the LC series resonant circuit becomes smaller.

This change changes the electrical constant of the resonant circuit group, for example, the voltage across it. Therefore, from the correspondence between the output frequency of the variable frequency power supply at the time when the voltage across both ends changes and the LC series resonant circuit that resonates at that frequency, it is determined that the switch connected in series to the LC series resonant circuit is in the on state. You can know that. Each LC series resonant circuit has a different resonant frequency. Therefore, even if two or more switches are turned on at the same time, it is possible to individually know that they are turned on.

(Example) Examples will be described below with reference to the drawings.

FIG. 1 shows N tactile sensors, that is, a switch 20, which independently turn on and off using a switch current state identification device according to an embodiment of the present invention. .

An example is shown in which the states of 202, . . . 2ON are identified.

In the figure, 21 indicates a variable frequency power supply. This variable frequency power supply 21 includes a relaxation oscillator 22 that sends out a sawtooth-shaped output Vt at a constant period, and an output Vt of this relaxation oscillator 22, and a constant amplitude in which the frequency changes in a pattern corresponding to the output Vt. The voltage/frequency converter 23 outputs a voltage signal Vi.

A resonant circuit group 25 is connected between output ends 24a and 24b of the voltage/frequency converter 23. This resonant circuit group 2
5 is the above-mentioned switch 201202,...2ON
N LC series resonant circuits 261.26□ connected in parallel between the output ends 24a and 24b each in series.
- Consists of 26N. Each of the LC series resonant circuits 26+, 262, . . Here, each LC series resonant circuit 261, 262 . ...26N and each switch 20+,'
20□, . . . 2ON and the resonance frequency of each LC series resonant circuit 261, 262 .

At both ends of the resonant circuit group 25, electrical constants of the resonant circuit group,
In this example, a peak detector 27 that detects the peak value of the voltage Vo across the resonant circuit group 25 is connected. The output Vp of the peak detector 27 is output from the A/D converter 2
8 and converted into a digital signal. Further, the output Vt of the relaxation oscillator 22 is also input to the A/D converter 28 and converted into a digital signal.

Vp and Vt converted into digital signals are introduced into the microprocessor 29. The microprocessor 29 includes, in this example, each LC series resonant circuit 26 . , 262.・
A table is provided that shows the correspondence between each switch 20+, 202°, . . . 2ON and Vt derived from the relationship between the resonant frequency of . And Vp
At each point in time when Vt falls below a steady value, Vt at that point
A switch name is selected from the list, and a signal corresponding to that switch name is output.

In addition, in FIG. 1, 30 indicates the internal resistance on the output side of the voltage/frequency converter 23.

With such a configuration, for example, when the switch 202 is turned on, Vp decreases when the output frequency of the voltage/frequency converter 23 reaches the resonant frequency of the LC series resonant circuit 262. I will do it. and,
The microprocessor 29 calculates Vt at the time when Vp drops.
A switch 20° is selected from among them, and a signal corresponding to this switch 20□ is output.

The above example is an example in which the switch 202 is turned on, or the output frequency of the voltage/frequency converter 23 is swept, so the LC series resonant circuit 26. ．． 2
6□, . . . 26N are never in a resonant state at the same time. Therefore, for example, all switches 201, 20□
, . . . 2ONs are in the on state, these on states can be identified by one frequency sweep. In this case, by grounding one end of the resonant circuit group 25, it is possible to multiplex transmit the on-state signals of multiple switches using only one signal line, thereby simplifying the overall configuration. This can improve reliability accordingly.

FIG. 2 shows an example in which a plurality of on/off type tactile sensors are mounted on the elbow joint of a robot by applying the present invention.

In the figure, 41 indicates the upper arm, 42 indicates the forearm, and 43
indicates the elbow joint. A coil spring 44 is installed between the upper arm 41 and the forearm 42 so as to surround the elbow joint 43. An integrated body 45 that integrates a tactile sensor and an LC series resonant circuit is attached to the outer periphery of the coil spring 44 so as to be distributed at a rate of 8 per turn.

Specifically, as shown in FIG. 3, the integrated body 45 is made by covering the coil spring 44 with a piece of rubber tube 46 with copper foil 47 glued to a part of the inside thereof, and combining the coil spring 44 and the copper foil 47. It constitutes an on/off type switch, that is, a tactile sensor. Ceramic oscillators 48 as LC series resonant circuits having different resonance frequencies are fixed to each rubber tube piece 46, and these ceramic oscillators 48 are connected in series to each tactile sensor to form a signal line 49 and a coil spring 44. are connected in parallel.

By adopting such a resonant circuit group configuration, it becomes possible to mount a tactile sensor on the elbow joint, which has been difficult in the past.

Note that the present invention is not limited to the embodiments described above. That is, in the embodiments described above, it is possible to identify whether the switch is on or off. Further, in the above embodiment, the state of each switch is detected from the change in the voltage across the resonant circuit group, but it may be detected from the change in the current flowing into the resonant circuit group.

[Effects of the Invention] As described above, according to the present invention, the states of a plurality of switches can be accurately identified no matter what state they are in or what relationship they have. Also,
Even if the number of switches increases, the state of each switch can be identified using only one signal line.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of an example in which the states of a plurality of tactile sensors are identified using the current state identification device of a switch according to an embodiment of the present invention, and Figures 2 and 3 are diagrams of a robot robot. FIG. 4 is a diagram for explaining an example of attaching a tactile sensor to an elbow joint, and is a schematic configuration diagram of a conventional example of a current state identification device of a switch. 20+, 20□,...20 N...Switch, 21
- Variable frequency power supply, 22... Relaxation oscillator, 23...
Voltage/frequency converter, 25...resonant circuit group, 26□,
262, 26 N...LC series resonant circuit, 27...
Peak detector, 28... A/D converter, 29... Microprocessor, 48... Ceramic oscillator. Applicant's agent Patent attorney Takehiko Suzue

Claims (5)

[Claims] (1) A device for identifying the current state of a plurality of switches that operate independently of each other, including a variable frequency power supply whose output frequency changes in a predetermined pattern over time, and a variable frequency power supply whose output frequency changes in a predetermined pattern over time, and a device whose resonant frequency is different. The number of LC series resonant circuits is the same as the number of switches, and the switches are connected in series between the output terminals of the variable frequency power supply.
A resonant circuit group formed by connecting series resonant circuits in parallel, a detection means for detecting an electrical constant of the resonant circuit group, and a detection means for detecting the electrical constant of the plurality of switches from the output of the detection means and the output frequency of the variable frequency power supply. 1. A current state identification device for a switch, comprising determining means for determining the current state. (2) The variable frequency power supply is comprised of a relaxation oscillator that sends out a sawtooth waveform output, and a voltage/frequency converter that operates by introducing the output of the relaxation oscillator. A device for identifying the current state of the switch described in . (3) The current state identification device for a switch according to claim 1, wherein each LC series resonant circuit constituting the resonant circuit group is comprised of a ceramic oscillator. (4) The current state identification device for a switch according to claim 1, wherein the detection means is constituted by a peak detector connected to both ends of the resonant circuit group. (5) The determination means makes the determination based on the correspondence between the output frequency of the variable frequency power supply at the time when the output of the detection means changes and the LC series resonant circuit that resonates at that frequency. The current state identification device for a switch according to claim 1.