JPH0663882B2 - Pressure sensor output signal preprocessor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention grasps an object, for example, by attaching it to a hand of a robot and measuring the pressure distribution of its gripping portion,
The present invention relates to a pressure sensor output signal preprocessing device for facilitating computer processing of an output signal of a pressure sensor that detects a gripping state such as a release or a slip.

[Prior Art] A pressure detection unit of a pressure sensor to which the present invention is applied includes, for example, three sets of pressure sensors that detect forces in the X-axis, Y-axis, and Z-axis directions of a pressure receiving surface and temperature characteristics of the pressure sensors. One set of temperature sensors for compensation is one unit (hereinafter referred to as a pressure sensor module), and a large number of the pressure sensor modules are arranged in a matrix. Spans hundreds of circuits.

No output signal preprocessing device for this type of pressure sensor has been found at present, but for a device consisting of a very small number of pressure sensor modules, a temperature characteristic compensating circuit as shown in FIG. 5 is connected to each output circuit. You can take the means to do so.

In FIG. 5, the temperature compensating circuit 2 eliminates the influence of the temperature characteristic of the semiconductor strange cage on the output of the pressure detecting unit 1 composed of a semiconductor bridge such as a semiconductor strain gauge. That is, in this temperature compensation circuit 2,
The signal from the pressure detecting unit 1 is received by the analog integrated circuit 3 and the analog integrated circuit 4, and the span and offset of the signal are adjusted by these integrated circuits and the span adjusting resistor 5 and the offset adjusting resistor 6, and the zero adjusting resistor is also adjusted. 7
And the analog integrated circuit 8 adjust the zero point of the signal. Furthermore, after the temperature compensation of the pressure signal is performed by the zero temperature characteristic compensation resistor 9 and the analog integrated circuit 8 and the span temperature characteristic compensation resistor 10 and the analog integrated circuit 11, the signal output signal
An output signal is output from 12. 13 is a power supply terminal, and 14 is an analog ground terminal.

[Problems to be Solved by the Invention] However, if such a conventional technique is applied to a large number of pressure sensor modules as described above, a temperature compensating circuit is connected to each pressure detecting unit as shown in FIG. Therefore, more than 1,000 analog integrated circuits, resistors, etc. must be installed. Furthermore, since the signal outputs of the respective pressure sensor modules are in parallel, the number of connection points with, for example, a microcomputer unit that performs signal processing becomes large. Therefore, there is a drawback that the size and weight reduction required for the pressure sensor for the robot hand cannot be achieved, and it is also uneconomical.

Therefore, it is an object of the present invention to eliminate the above-mentioned drawbacks and to provide a pressure sensor output signal preprocessing device capable of economically measuring a pressure distribution.

[Means for Solving the Problems] According to the present invention, in order to achieve the above object, a plurality of pressure detection module parts having unique addresses, and a plurality of pressures arranged in the pressure detection module part are provided. A detection unit, a temperature detection unit arranged in the pressure detection module unit, for detecting the temperature of the pressure detection unit, arranged in the pressure detection module unit, and outputs the outputs of both the pressure detection unit and the temperature detection unit. A first analog switch that opens and closes; a second analog switch that is disposed in the pressure detection module unit and that controls the first analog switch at a first address given to the pressure detection module unit; A second output from the output group of both the pressure detection unit and the temperature detection unit sent via the first analog switch of the module unit is output. An analog signal switcher for sequentially selecting the address, the first address of the pressure detection module unit, and the second address of each output signal of the pressure detection unit and the temperature detection unit of the pressure detection module unit. An address reproducing unit for generating the address, a tactile unit including the pressure detection module unit, an analog signal switch and an address reproducing unit, an address generating unit connected to the address reproducing unit for generating the first and second addresses, An analog-digital converter for converting the pressure signal and the temperature signal sent from the pressure detection unit and the temperature detection unit addressed by the address reproduction unit through the analog signal switching unit into an analog-digital converter, and the analog-digital conversion Using the pressure signal and the temperature signal digitized by a vessel And an address processing unit for supplying the code values of the first and second addresses to the address generation unit at the same time by compensating the temperature of the pressure signal by operating a predetermined arithmetic expression The first and second addresses supplied from the generation unit to the address reproduction unit are serially transferred at a timing of a predetermined synchronous clock.

[Operation] In the present invention, a large number of pressure detection modules three-dimensionally constructed by a plurality of pressure detection units are arranged in a matrix, and each module is selectively swept by the vertical axis address and the horizontal axis address, and further selected. Select and sweep the output of each pressure detector in the module one by one by signal address,
By performing temperature compensation such as offset and span for each pressure detecting unit by using the output of the temperature detecting unit and a microcomputer, the pressure distribution in a two-dimensional plane shape or a three-dimensional three-dimensional shape is measured.

Further, in the present invention, since the temperature detection unit is provided for each pressure detection module composed of a plurality of bridges and the amplifier of the temperature measurement circuit is shared with the amplifier of the pressure detection circuit, the configuration is simplified and downsized. To be achieved.

Further, in the present invention, the pressure detection module and the circuit for generating and reproducing the address in order to supply the address value of the signal from the signal processing unit to the tactile unit are provided respectively, and the data transfer is performed by the serial method. A small number of connection points are required, and miniaturization can be achieved.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a circuit configuration of an embodiment of the present invention. Where 15
Is a pressure detection block that detects pressure sensations such as pressure sense and tactile sense with temperature detection, 16 is an amplifier that amplifies the output of the pressure detection block 15, 51 is an address regeneration unit that selectively sweeps the pressure detection module, and 49 is each of the above units The tactile unit is composed of 15, 16 and 51 and is attached to, for example, a robot hand. Reference numeral 17 denotes a microcomputer unit that performs temperature compensation of the output of the amplification unit 16 and the like, and 52 denotes an address generation unit that receives a command from the microcomputer unit 17 and extracts a signal of an arbitrary detector in the tactile unit 49. 50 is composed of the above-mentioned respective parts 17, 52,
A signal processing unit that controls a plurality of tactile units (one unit in the embodiment) and is mounted on, for example, the arm of a robot. This embodiment consists of these circuit elements 49, 50.

The pressure detection block 15 is composed of a plurality of pressure detection modules 18 and a single analog signal switch 19. Although not shown in the drawing, a large number of pressure detection modules 18 are arranged in a matrix in the vertical and horizontal directions and given a unique address,
A decode line group 43 and a decode line group 44 of an address reproducing unit, which will be described later, are connected to each pressure detection module 18.

In each pressure detection module 18, a plurality of pressure detection units 1 _X , 1 _Y , 1 _Z provided in consideration of three-dimensional pressure measurement and the like,
One temperature detector 20 for detecting the temperature of the pressure detector is provided. The pressure detectors 1 _X , 1 _Y and 1 _Z are bridges such as semiconductor strain gauges, and the temperature detector 20 is a thermistor. Further, 21 _X , 21 _Y , 21 _Z and 21 _T are signal switch sections as analog switches for opening and closing the detection outputs of the pressure detecting sections 1 _X , 1 _Y and 1 _Z and the temperature detecting section 20, and 22 is for this signal. Each module via switch
It is a module switch as an analog switch that controls the opening and closing of the detection output in units of 18 units, and the above-mentioned one set of switch units 21 _X , 21 _Y , 2
1 _Z and 21 _T open and close.

Switch 22 for each module is a pressure detection module
It is composed of switches SX and SY that open and close in response to an instruction of a decode signal on the horizontal and vertical axes indicating the address of 18, and a resistor R that potential-codes the open and close operation. The axis will switch SX and switch when the associated pressure detection module 18 is selected by the selection of the decoder described later.
It is specified by closing SY and simultaneously opening all signal switch parts 21 _X , 21 _Y , 21 _Z and 21 _T in the module to which it belongs.

Further, one temperature detecting unit 20 is connected to each of the pressure detecting units 1 _X , 1 _Y and 1 _{Z with} respect to the common power supply terminal 13 and the analog ground terminal 14, and the outputs of these detecting units are connected. The above-mentioned pair of signal switch parts 21 _X , 21 _Y , 21 _Z and 21 _T are connected to the terminals.

As shown in FIG. 2, the analog signal switch 19 is composed of a plurality of switches, receives signals from each pressure detection module 18, and outputs a set of signals as a signal decoder described later.
Selective output based on the output value of 25.

Amplifier section 16 connected to the output terminal of analog signal switch 19
Is composed of analog integrated circuits 3, 4 and 11 which operate as a differential amplifier and a plurality of resistors R _{0 to} R ₃ as shown in FIG. The output e ₀ of the amplifier 16 is the inputs e ₁ , e ₂
Then, it is given by the following equation (1).

The amplifying unit 16 is resistant to inductive noise and therefore has less common-mode voltage noise, and has the advantage that a floating power supply is not required because the bridge of the detecting unit 1 and the ground of the amplifying unit 16 are common (ground line common connection).

The microcomputer unit 17 is composed of a plurality of constituent elements.
Here, 26 is an A / D (analog-digital) converter connected to the output terminal of the amplification section 16, and A / D-converts the pressure signal and the temperature signal amplified by the amplification section 16. 27 is an A / D converter
For temporary storage that temporarily stores the digital signal output from 26
RAMs (random access memories) 28 and 29 are a processor for multiplication and a processor for division that perform an operation for temperature compensation of the data digitized by the A / D converter 26.

Reference numeral 30 is a ROM (read only memory) in which arithmetic expressions, constants, control programs, etc. are stored in advance, 31 is a corrected data storage RAM that stores the temperature-compensated detection data by computation, and 32 is the temperature-compensated detection data. A signal output port for output to the outside, and 33 is a CPU (central processing unit) that controls the whole. Further, 35 is a data bus inside the microcomputer unit 17, 36 is an address bus of the microcomputer unit 17, and 37 is a microcomputer unit 17.
Is a data output data bus. 38 and 39 are digital power supply and ground terminals for the microcomputer section 17,
Reference numerals 40 and 41 are positive and negative power supply terminals for the operational amplifier (operational amplifier) of the amplification section 16.

Reference numeral 52 denotes an address generator connected to the address bus 36 and the data bus 35 of the microcomputer unit, which includes a data converter 54 for converting input parallel data into serial data and a clock generator 55 for transferring its output. is there.

Reference numeral 51 is an address reproducing unit composed of an inverter 53 and decoders 23 to 25 for reproducing serial data from the address generating unit 52 into parallel data together with a clock supplied at the same time.

42 is a decode line group that is output from the signal decoder 25 and is connected to the analog signal switch 19, 43 is a output from the vertical axis decoder 23, and the switch SY of each module switch unit 22 is provided for each vertical axis.
The vertical axis decode line group connected to and the vertical axis 44 are output from the horizontal axis decoder 24, and switch modules 22 for each module are provided for each horizontal axis.
It is a horizontal axis decode line group connected to the switch SX.

In the above configuration, the CPU 33 determines, based on the control program stored in the ROM 30, which pressure detection module of which pressure detection module among the plurality of pressure detection modules 18 outputs the output to the signal output data bus 37. Once you decide
The address of the pressure detection module and the address of the pressure detection unit are output to the data converter of the address generation unit 52.

Here, the pressure detection unit 1 _X in each pressure detection module 18
The addresses given in advance to 1 _Y , 1 _Z and the temperature detection unit 20 are addresses specified for each detection unit. For example, the code value when the signal address, the vertical axis address and the horizontal axis address are arranged is Represent.

Next, the relationship between the address generator 52 and the address reproducer 51 will be described with reference to FIG.

The address generator 52 converts the input address value A of the pressure detection module and its signal into serial data B by the data converter 54, and sends it out in time series by the clock generator 55.

The transfer method at this time is such that the data corresponding to the two systems of the decoder of the address reproducing unit 51 described later share the cycle of the clock C (S _{0 to 3} and Y in the embodiment).
Separated from ₀ to ₃ and X ₀ to ₃ ). Further, when the bit lengths of the two data are different, in order to align the end points of the transfer, the sending out of the shorter bit length (signals X _{0 to 3 in} the embodiment) is delayed by a certain number of clocks. Thus, the serial data B and the clock C are supplied to the address reproducing unit 51. In the address reproduction unit 51, the decoders 23 to 25 having the shift register structure store the serial data B at the edge of the clock C and reproduce the parallel data at the same time when the clock C is stopped. In the reproducing system at this time, the two systems operate in parallel by separately inputting the clock C and its inverted clock C ', which are the input and output of the inverter 53, to the decoders 25, 23 and the decoder 24, respectively.

When the data transmission / reception between the address generation unit 52 and the address reproduction unit is completed as described above, each decoder 23 to 25 decodes the signal line, the vertical axis line and the horizontal axis line corresponding to the reproduced address value to the decoding line group 42. ， Selected from the decode line group 43 and the decode line group 44,
Only the analog selector 19 and the switches SX, SY connected to these selected lines are turned on (conducting).

That is, as shown in FIG. 2, the vertical axis decoder 23 uses the decode line group 43 to detect the column-direction pressure detection module 18.
The switch SY in the switch is selectively turned on, and the horizontal axis decoder 24 selectively turns on the switch SX in the row-direction pressure detection module 18 through the decode line group 44. When both switches SX and SY are turned on, the signal switch 22
When turned on, the pressure and temperature signals of the pressure detection module 18 to which the switch 22 belongs (specified by the address) are output all at once. In this way, the signal decoder 25 sequentially turns on any of the switches in the analog switch 19 in order to select a set of signals from the signals of the pressure detection module 18 selected by the decoders 23 and 24 described above.

As a result, the specific pressure detectors 1 _X , 1 _Y , 1 _Z having the address designated by the CPU 33 are selected, and the output signal of the selected pressure detector is amplified by the amplifier 16. Similarly, the output of the temperature detection unit 20 is changed only by the address by the CPU 33, and the amplification unit goes through the signal selection process described above.
Amplified by 16.

Next, the pressure signal and the temperature signal amplified by the amplifier 16 are
A / D conversion is performed by the A / D converter 26. The A / D-converted digital pressure signal and temperature signal are distinguished from each other in the temporary storage RAM 27 via the internal data bus 35 and stored in different areas, and further stored in the CPU 33, the multiplication processor 28, and the division processor. A calculation for temperature compensation of the pressure signal is performed by the processor 29. Here, the multiplication processor 28 and the division processor 29 are used to speed up the above-described compensation calculation.

Such compensation calculation is performed as follows. First, A / D converter 2
The analog value Vop of the pressure signal input to 6 is the offset that occurs when pressure is not applied to the pressure detection unit 1 (representative number of 1 _X , 1 _Y , 1 _Z ) and the proportional constant that determines the span. Approximately using and, The pressure P applied to the pressure detection unit 1 can be obtained from the following equation (3).

However, T: absolute temperature of the pressure detection unit 1, a ₀ , a ₁ , a ₂ , b ₀ , b ₁ , b ₂ : known constants determined individually for the pressure detection unit 1.

In addition, the analog value V of the temperature signal input to the A / D converter 26
_OT can be approximately expressed as V _OT = C ₀ + C ₁ T ₀ when the temperature detection unit 20 is, for example, a thermistor. Therefore, the temperature T ₀ can be obtained from the following equation (4). .

However, C ₀ and C ₁ : known constants determined for each temperature detecting unit 20 T ₀ : absolute temperature of the temperature detecting unit 20.

Therefore, if the temperature detection unit 20 and the pressure detection unit 1 are installed sufficiently close to each other so that the temperature T ₀ of the temperature detection unit 20 is considered to be the temperature T of the pressure detection unit 1, the above (4) By using the temperature T ₀ calculated by the equation as T, it is possible to calculate the accurate pressure value P by removing the influence of the temperature T from the above equation (3). In this way, the calculated digital pressure data P is output to the outside from the signal output data bus 37 via the signal output port 32 and, at the same time, is stored in the corrected data storage RAM 31 and is always required. It can be output at any time.

As described above, the output signal of the specific pressure detection unit 1 is arithmetically processed by the microcomputer unit 17 and output to the signal output data bus 37. Similarly, the outputs of the other pressure detection units 1 are detected by being sequentially addressed via the vertical axis decoder 23, the horizontal axis decoder 24, and the signal decoder 25, and are processed by the microcomputer unit 17. , To the data output data bus 37. Pressure detection unit 1 of a plurality of matrix-shaped pressure detection modules 18
When the sweeping of all of the temperature detecting section 20 is completed in this way, the data file of the pressure distribution is completed in the corrected data storage RAM 31.

Thus, in this example, the pressure detection module 18 constructed with a plurality of pressure detection units is used.
Are arranged in a matrix, and the vertical axis decoder 23 and the horizontal axis decoder 24 sequentially select and sweep out the signal of one pressure detection module 18, and then select and take out the signal and the signal decoder 25 and the analog signal. An address signal for further selective sweeping with the signal switcher 19 and for sequentially extracting one set of detection signals from the signals is serially transferred, and a pressure signal and a temperature signal are amplified in the same path by sharing an amplifier. After that, since temperature compensation such as offset and span is performed, the same signal can be bundled in the pressure detection unit, and the number of connections between the lead wire from the pressure detection module 18 and the tactile unit and signal processing unit is reduced. Moreover, the number of analog signal switching devices is reduced. Therefore, the tactile part (in which the sensor array and the IC such as the multiplexer are integrated) can be miniaturized.

It should be noted that modularization of the pressure detection unit 1 in units of several units is, for example, for constructing a three-component force detection pressure-sensitive module that decomposes and detects applied pressure into three-component forces orthogonal to each other as a single component. , Is an effective means.

[Effects of the Invention] As described above, according to the present invention, a large number of pressure detection modules constructed by a plurality of pressure detection units are arranged in a matrix, and the pressure detection modules are provided on a vertical axis assigned to each module. Address and horizontal axis address are sequentially selected, and the output of each pressure detection unit in the selected module is further selected one by one by the signal address, and each pressure detection unit is selected for the selected detection signal. Since temperature offset compensation is performed for each offset span, the outputs of a plurality of pressure detection units are swept like in the conventional device of FIG. 6 and a temperature compensation circuit is separately provided for each pressure detection unit. It is not necessary, the number of circuit components is reduced as a whole, and not only the size reduction is achieved, but also the pressure distribution can be measured inexpensively and economically.

In addition, in the case of supplying the pressure detection module and the address value of the signal from the signal processing unit to the haptic unit,
An address generator and an address reproducer are provided,
Since the transfer method is serial, only a small number of connection points are required for each other, and miniaturization can be further promoted.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of an embodiment of the present invention, FIG. 2 is a circuit diagram showing a configuration example of the analog signal switch shown in FIG. 1, and FIG. 3 is a configuration example of an amplifier section shown in FIG. FIG. 4, FIG. 4 is a diagram for explaining the operation of the address generation unit and address reproduction unit of FIG. 1, FIG. 5 is a circuit diagram showing a temperature characteristic compensation circuit of a conventional pressure sensor, and FIG. FIG. 3 is a block diagram showing a system configuration example when a pressure distribution is measured using a pressure sensor and its temperature characteristic compensation circuit. 1 ... Pressure detection unit, 2 ... Temperature characteristic compensation circuit, 3 ... Analog integrated circuit, 4 ... Analog integrated circuit, 5 ... Span adjustment resistor, 6 ... Offset adjustment resistor, 7 ... Zero adjustment resistor, 8 ... Analog integrated circuit, 9 ... Zero temperature characteristic compensation resistance, 10 ... Span temperature characteristic compensation resistance, 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 ... Pressure detection module, 19 ... Analog signal selector, 20 ... Temperature detection section, 21 ... Signal Switch, 22 …… Module switch, 23 …… Vertical axis decoder, 24 …… Horizontal axis decoder, 25 …… Signal decoder, 26 …… A / D converter, 27 …… Temporary storage RAM, 28 …… Multiplying processor, 29 ... Dividing processor 30 …… ROM, 31 …… Corrected data storage RAM, 32 …… Signal output port, 33 …… CPU, 35 …… Internal data bus, 36 …… Address bus, 37 …… Signal output data bus, 38 …… Digital power supply terminal, 39 …… Digital ground terminal, 40 …… Positive power supply terminal for operational amplifier, 41 …… Negative power supply terminal for operational amplifier, 42… Decode line group, 43… Decode line group, 44… … Decode line group, 49 …… Tactile unit, 50 …… Signal processing unit, 51 …… Address reproducing unit, 52 …… Address generating unit, 53 …… Inverter, 54 …… Data converter, 55 …… Clock generator .

Claims (5)

[Claims] 1. A) a plurality of pressure detection module parts having unique addresses, b) a plurality of pressure detection parts arranged in the pressure detection module part, and c) arranged in the pressure detection module part, A temperature detection unit for detecting the temperature of the pressure detection unit, d) a first analog switch which is disposed in the pressure detection module unit and opens and closes outputs of both the pressure detection unit and the temperature detection unit, e) the pressure A second analog switch disposed in the detection module section for controlling the first analog switch at a first address given to the pressure detection module section; f) the first analog of the pressure detection module section An analog signal for sequentially selecting one output from the output groups of both the pressure detection unit and the temperature detection unit sent via a switch at a second address G) an address reproducing unit for generating the first address of the pressure detecting module unit and the second address for each output signal of the pressure detecting unit and the temperature detecting unit of the pressure detecting module unit; H) a haptic part comprising the pressure detection module part, an analog signal switch and an address reproducing part, i) an address generating part connected to the address reproducing part and generating the first and second addresses, j) the An analog-digital converter for converting the pressure signal and the temperature signal sent from the pressure detection unit and the temperature detection unit addressed by the address reproduction unit through the analog signal switching device, and k) the analog A predetermined arithmetic expression predetermined using the pressure signal and the temperature signal digitized by a digital converter And an information processing unit for supplying the code values of the first and second addresses to the address generating unit at the same time by performing temperature compensation of the pressure signal by calculation, and from the address generating unit to the address reproducing unit. The pressure sensor output signal pre-processing device, wherein the first and second addresses to be supplied to are configured to be serially transferred at a timing of a predetermined synchronous clock. 2. The apparatus according to claim 1, wherein each of the first and second addresses is divided into two, and the first and second addresses divided into the two are transferred alternately. A pressure sensor output signal preprocessing device characterized by being configured as follows. 3. The device according to claim 2, wherein the first and second addresses are divided into two parts, and one transfer time is delayed when a data length imbalance occurs. A pressure sensor output signal preprocessing device characterized by: 4. The apparatus according to any one of claims 1 to 3, wherein the address reproducing section is composed of two reproducing systems operating with two synchronous clocks having different phases. A pressure sensor output signal preprocessing device characterized by: 5. The apparatus according to claim 1, wherein the plurality of pressure detection units are configured to include a pressure sensitive module that decomposes and detects the applied pressure into component forces in three directions orthogonal to each other. A pressure sensor output signal preprocessing device characterized by the above.