JPH0257255B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention is attached to a robot's hand, for example, and measures the pressure distribution of the gripping part to determine the gripping state such as grasping, releasing, sliding, etc. The present invention relates to a pressure sensor output signal preprocessing device for facilitating computer processing of the output signal of a pressure sensor to be detected.

[Prior Art and its Problems] Although this type of pressure sensor output signal preprocessing device is not currently available, there is a prior art similar to the present invention as shown in FIG. The temperature compensation circuit 2 removes the influence of temperature on the output of the pressure detection section 1, which is composed of a semiconductor bridge such as a semiconductor strain gauge. That is, in this temperature compensation circuit 2, the signal from the pressure detection section 1 is received by the analog integrated circuit 3 and the analog integrated circuit 4, and the span and the span of the signal are adjusted by these integrated circuits, the span adjustment resistor 5, and the offset adjustment resistor 6. The offset is adjusted, and the zero point of the signal is adjusted by the zero point adjustment resistor 7 and the analog integrated circuit 8. Further, after temperature compensation of the pressure signal is performed by the zero point temperature characteristic compensation resistor 9, the analog integrated circuit 8, the span temperature characteristic compensation resistor 10, and the analog integrated circuit 11, an output signal is output from the signal output terminal 12. 13 is a power supply terminal, and 14 is an analog ground terminal.

However, when using such conventional technology to measure the pressure distribution of pressure distributed over a plane as described above, for example, as shown in FIG. Therefore, a large number of temperature compensation circuits 2 must be arranged in parallel, which is very uneconomical.

[Object of the Invention] An object of the present invention is to provide a pressure sensor output signal preprocessing device that can economically measure pressure distribution.

[Summary of the Invention] This invention sweeps and extracts the outputs of a large number of pressure sensing sections arranged in a matrix using the vertical axis address and the horizontal axis address, and performs temperature compensation such as offset and span for each individual pressure sensing section. By performing this using the output of a temperature sensor and a microcomputer, pressure distribution can be measured economically.

[Embodiments of the Invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 3 shows an embodiment of the present invention, which includes a pressure detection block 15, an amplification section 16, and a microcomputer section 17. The pressure detection block 15 includes a plurality of pressure detection sections 1 made of a semiconductor such as a semiconductor strain gauge and arranged in a matrix, a temperature detection element 18 made of a thermistor or the like connected in parallel to each pressure detection section 1, and One set of pressure detection section 1 and temperature detection element 1
A vertical axis analog switch section 19 is connected every 8 and opens and closes these outputs for each vertical axis (column direction), and a vertical axis analog switch section 19 is connected to the rear stage of the vertical axis analog switch section 19 to switch between the pressure detection section 1 and the temperature detection element 18. Horizontal axis analog switch section 20 that opens and closes the output for each horizontal axis (row direction)
Consists of etc. Vertical axis analog switch section 1
9 and the horizontal axis analog switch section 20 are each made up of three analog switches 21 that open and close at the same time using a control voltage, and are connected to the output of the pressure detection section 1 and the output of the temperature detection element 18.

The amplifier section 16 connects all the horizontal axis analog switch sections 2
It is a single amplifier unit connected to the output of 0, and includes three analog integrated circuits 3, 4 and 11 for pressure signal amplification, and an analog integrated circuit 22 for temperature signal amplification.
It is composed of.

The microcomputer section 17 applies a control voltage to all the horizontal axis analog switch sections 20 of the corresponding horizontal axis in accordance with the horizontal axis address described later, and controls the opening/closing of the horizontal axis decoder 23, and the corresponding horizontal axis decoder 23 controls the opening/closing of the corresponding horizontal axis analog switch section 20 according to the horizontal axis address described later. A vertical axis decoder 2 applies a control voltage to the vertical axis analog switch section 19 and controls its opening/closing.
4. An analog signal switching section 25 which is connected to the output of the amplification section 16 and alternately switches and outputs the amplified analog pressure signal and temperature signal; ) Temporary storage for temporarily storing the A/D converter 26 to be converted and the digital output signal of the A/D converter 26
RAM (random access memory) 27, A/D
A multiplication coprocessor 28 and a division coprocessor 29 perform calculations for temperature compensation on data digitized by the converter 26, a ROM (read only memory) 30 stores calculation formulas, constants, control programs, etc. in advance; Corrected data storage RAM that stores compensated detection data
31. Signal output port 32 that outputs temperature compensated detection data to the outside, performs overall control.
CPU (central processing unit) 33, and CPU 33
The address output port 34 outputs the pressure detection unit address from the horizontal axis decoder 23 and the vertical axis decoder 24.

35 is an internal data bus of the microcomputer section 17, 36 is an address bus of the microcomputer section 17, and 37 is an internal data bus of the microcomputer section 17.
38 is a digital ground terminal of the microcomputer section 17, 39 is a digital power supply electronic of the microcomputer section 17,
40 is a negative power supply terminal for the operational amplifier of the amplifier section 16;
1 is a positive power supply terminal for the operational amplifier of the amplifier section 16, 42
43 is a horizontal axis line group that comes out of the horizontal axis decoder 23 and connects to the gate of each horizontal axis analog switch section 20, and 43 comes out of the vertical axis decoder 24 and connects to the gate of the vertical axis analog switch section 19 for each vertical axis. The vertical axis is a group of lines.

Among the plurality of pressure detection units 1 by the CPU 33,
When it is determined which pressure detection unit 1 outputs the output to the signal output data bus 37, the CPU 33
outputs the address of the pressure detection section to the horizontal axis decoder 23 and the vertical axis decoder 24 via the address output port 34. Here, the address of the pressure detection section is a specific address given to each pressure detection section, and is made up of, for example, a vertical axis address and a horizontal axis address. Each of the decoders 23 and 24 decodes the input address, selects the vertical axis and horizontal axis lines corresponding to the address from the vertical axis line group 43 and the horizontal axis line group 42, and selects the lines connected to these lines. Only the vertical axis analog switch section 19 and the horizontal axis analog switch section 20 are turned on (conducted).

As a result, the specific pressure detection section 1 at the address specified by the CPU 33 and the temperature detection element 18 for measuring the temperature of this pressure detection section 1 are selected, and their output signals are amplified by the amplification section 16. . That is, the pressure signal from the pressure detection section 1 is amplified by the analog integrated circuit 3, analog integrated circuits 4 and 11, and the temperature signal from the temperature detection element 18 is amplified by the analog integrated circuit 22. The amplified pressure signal and temperature signal are switched by an analog signal switching unit 25 and are alternately converted into A/D converter 26.
D-converted. The A/D converted digital pressure signal and temperature signal are stored in the temporary storage RAM 27 via the internal data bus 35, and are further stored in the CPU 3.
3. The multiplication coprocessor 28 and the division coprocessor 29 perform calculations for temperature compensation of the pressure signal. Here, multiplication coprocessor 2
8 and the division coprocessor 29 are used to speed up the above-mentioned compensation calculation.

Such compensation calculation is performed as follows. First, the pressure signal input to the analog signal switching section 25 is
Approximately, using the offset that occurs when no pressure is applied to the pressure detector 1 and the proportionality constant that determines the span, V _pp = a ₀ + a ₁ T + a ₂ T ² + (b ₀ + b ₁ T + b ₂ T ² )・P offset Since it can be expressed as a proportionality constant, pressure P can be found from the following formula.

P=a ₀ +a ₁ T+a ₂ T ² −V _pp /b ₀ +b ₁ T+b ₂ T ² ……… However, V _pp : Pressure signal input to analog signal switching unit 25 T : Absolute temperature of pressure detection unit 1 P: Pressure applied to the pressure detection unit 1 a ₀ , a ₁ , a ₂ , b ₀ , b ₁ , b ₂ : Known constant determined individually for the pressure detection unit 1 Also input to the analog signal switching unit 25 The temperature signal can be approximately expressed as V _pT =C ₀ +C ₁ T when the temperature detection element 18 is a thermistor, for example, so the temperature T can be determined from the following equation.

T=V _pT −C ₀ /C ₁ ...... However, V _pT : Temperature signal input to the analog signal switching section 25 C ₀ , C ₁ : Known constant determined for each temperature detection element 18 T _pT : Temperature detection Absolute temperature of element 18 Therefore, if temperature detection element 18 and pressure detection part 1 are installed close enough that the temperature of temperature detection element 18 can be considered as the temperature of pressure detection part 1, the above-mentioned Using the temperature T calculated by
From the above equation, it is possible to calculate an accurate pressure value with the influence of temperature removed. In this way, the calculated pressure data is output to the outside via the signal output port 32, and at the same time is stored in the corrected data storage RAM 31, so that it can be output whenever necessary. There is.

As described above, the pressure signal from a particular pressure detection section 1 is processed by the microcomputer section 17 and output to the signal output data bus 37. Similarly, the pressures of the other pressure detection units 1 are sequentially addressed via the vertical axis decoder 24 and the horizontal axis decoder 23, and are arithmetic-processed by the microcomputer unit 17 and sent to the signal output data bus 37. Output. When all the plurality of pressure detection units 1 are swept in this manner, a pressure distribution data file is completed in the corrected data storage RAM 31.

The pressure detection unit 1 is also suitable for a semiconductor bridge circuit of a three-component force detection pressure-sensitive module that detects the applied pressure by decomposing it into three mutually perpendicular force components. Furthermore, the temperature detection element 18 does not need to be used in pairs with the pressure detection section 1; for example, one temperature detection element 18 may be used for each of the three pressure detection sections 1 to measure the temperature, and temperature compensation may be performed using formulas. It is obvious that one temperature detection element 18 may be used in the pressure detection block 15 to measure the temperature and perform temperature compensation in the same way.

[Effects of the Invention] As explained above, according to the present invention, the outputs of a large number of pressure detection sections arranged in a matrix are swept using the vertical axis address and the horizontal axis address as described above, and the individual pressures are detected. Temperature compensation such as offset and span for each detection section is performed using a microcomputer, so instead of sweeping the outputs of multiple pressure detection sections as shown in Figure 2, temperature compensation is applied to the output of each pressure detection section. There is no need to provide a separate compensation circuit, and the pressure distribution can be measured as a whole at low cost and economically.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a temperature compensation circuit of a conventional pressure sensor, Fig. 2 is a block diagram showing an example of a system configuration when measuring pressure distribution using a conventional pressure sensor and its temperature compensation circuit, and Fig. 3 is a circuit diagram showing a conventional pressure sensor and its temperature compensation circuit. The figure is a circuit diagram showing an embodiment of the invention. 1...Pressure detection section, 2...Temperature compensation circuit, 3...
...analog integrated circuit, 4...analog integrated circuit,
5... Span adjustment resistor, 6... Offset adjustment resistor, 7... Zero point adjustment resistor, 8... Analog integrated circuit, 9... Zero point temperature characteristic compensation resistor, 10... Span temperature characteristic compensation resistor, 11... Analog integrated circuit, 12... signal output terminal, 13... power supply terminal,
14...Analog ground terminal, 15...Pressure detection block, 16...Amplification section, 17...Microcomputer section, 18...Temperature detection element, 19...
... Vertical axis analog switch section, 20 ... Horizontal axis analog switch section, 21 ... Analog switch, 22
... Analog integrated circuit, 23 ... Horizontal axis decoder,
24...Vertical axis decoder, 25...Analog signal switching unit, 26...A/D converter, 27...RAM for temporary storage, 28...Coprocessor for multiplication, 29...
...Coprocessor for division, 30...ROM, 31...
...RAM for storing data after correction, 32...Port for signal output, 33...CPU, 34...Port for address output, 35...Internal data bus, 36...
Address bus, 37...Data bus for signal output,
38...Digital earth terminal, 39...Digital power supply terminal, 40...Negative power supply terminal for operational amplifier, 41...Positive power supply terminal for operational amplifier, 42...
Horizontal axis line group, 43... Vertical axis line group.

Claims (1)

[Claims] 1. A plurality of pressure detection sections having unique addresses consisting of upper addresses and lower addresses, a temperature detection section that detects the temperature of the pressure detection sections, and a connection to the pressure detection section and the temperature detection section. a first analog switch that turns on and off the outputs of both of the detection sections and sends the output to a signal line belonging to the lower address of the pressure detection section; a first analog switch connected to each of the signal lines and turns on and off the signal line; 2 analog switch, an address generation section that sequentially generates the upper address and the lower address of the pressure detection section, and a first switch drive that opens and closes the first analog switch belonging to the upper address supplied from the address generation section. a second switch driving section that opens and closes the second analog switch belonging to the lower address supplied from the address generation section; a second switch driving section that opens and closes the second analog switch belonging to the lower address supplied from the address generation section; an analog-to-digital converter that converts the pressure signal and temperature detection signal outputted through the first analog switch and the second analog switch from analog to digital; and the pressure signal and temperature detection digitized by the analog-to-digital converter. A pressure sensor output signal preprocessing device, comprising: a microcomputer section that performs temperature compensation of the pressure signal by calculating according to a predetermined arithmetic expression using the signal. 2. In the device according to claim 1,
A pressure sensor output signal preprocessing device comprising a three-component force detection pressure-sensitive module that detects the applied pressure by decomposing the applied pressure into three mutually orthogonal component forces by the pressure detection section. 3. In the device according to claim 1 or 2, an intersection point of a matrix wiring consisting of a control line for driving the first analog switch and the signal line that intersects the control line. A pressure sensor output signal preprocessing device characterized in that the pressure detection section is disposed in each of the pressure sensor output signals. 4. The device according to any one of claims 1 to 3, wherein the address generating section, the first switch driving section, the second switch driving section, and an analog-to-digital converting section. A pressure sensor output signal preprocessing device, characterized in that it is included in the microcomputer section.