JPH04140687A - Ultrasonic object recognition device - Google Patents

Abstract

PURPOSE:To improve recognition speed by correcting the initial value of address arithmetic circuit in accordance with the temperature change and memorizing reflecting wave data at roughly determined position in a memory. CONSTITUTION:Ultrasonic sound is emitted from an ultrasonic sensor 2 to an object 14 and the reflected sound is received by the sensor 2. The received signal is converted with an A/D converter circuit 5 into digital signal 8 and is memorized in a memory 6 following the address 12 calculated with an address arithmetic circuit. On the other hand, a temperature sensor 13 detects temperature and inputs in an initial value correction means 10. The means 10 does a correction calculation to decrease an initial value 11 when the temperature is high and to increase it when the temperature is low so as to keep it constant. Then the initial value 11 is input in the arithmetic circuit 9, and the address of the reflected sound data in the memory 6 is calculated to output to the memory 6. And the reflected sound data is memorized at a roughly determined position in the memory 6. Therefore, searching of reflected sound data in the memory device is not necessary even in the case of temperature change, and thus the speed of object recognition is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an ultrasonic object recognition device using an ultrasonic element in a system such as ultrasonic holography and image reproduction.

[Prior Art] In an acoustic holography system that reproduces a target object image by irradiating the target object with ultrasonic waves and measuring the reflected waves, an ultrasonic object recognition device that recognizes the object using an ultrasonic element is used. It is deployed.

Conventionally, some ultrasonic object recognition devices employ a method of controlling the gain of an amplifier of a transmitter or a receiver depending on the distance between an ultrasonic sensor and a target object.

[Problems to be Solved by the Invention] However, in the conventional ultrasonic object recognition device described above, the speed of ultrasonic waves also changes when the temperature changes, so the reflected wave data from an object stored in the storage device is based on the temperature. As the value changes, its memory location also moves. Therefore, it is necessary to search the reflected wave data in the storage device every time the temperature changes, resulting in a disadvantage that the speed of object recognition decreases.

Another drawback is that the waveform of the target object cannot always be obtained at the same timing.

Therefore, this invention solves the above-mentioned conventional problems, and
An object of the present invention is to provide an ultrasonic object recognition device that does not require searching for reflected wave data in a storage device even when the temperature changes, and can improve object recognition speed accordingly.

[Means for Solving the Problems] The gist of the present invention is at least to include a transmitting circuit that generates a burst wave, and a transmitting circuit that transmits ultrasonic waves to a target object and transmits ultrasonic waves that are reflected from the target object. An ultrasonic sensor that receives waves, an amplifier circuit that amplifies the output from the ultrasonic sensor, an A/D conversion circuit that generates reflected wave data from the output of the amplifier circuit, and from the A/D conversion circuit. a storage device that stores reflected wave data of the storage device; an address calculator that calculates an address for storing the reflected wave data in the storage device; and a computer that processes the reflected wave data of the storage device to recognize the target object. An ultrasonic object recognition device comprising a data processing means that determines the temperature.

and an initial value correcting means for correcting the initial value of the address calculator based on the detection result of the temperature detecting means so that the storage position of the reflected wave data does not change. There is a particular thing.

[Operation] Therefore, the temperature detection means detects the temperature and the signal thereof is input to the initial value correction means. The initial value correction means corrects the initial value (start address) of the address of the reflected wave data stored in the storage device according to the input temperature,
Output to address calculator. This address calculator calculates the above-mentioned address based on the corrected initial value and outputs it to the storage device, so that the reflected wave data is always stored at a substantially fixed position in the storage device.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In the functional block diagram of FIG. 1, 1 is a transmission circuit that generates a burst wave, 2 is an ultrasonic sensor that transmits and receives ultrasonic waves to a target object 14, and 3 is a vibration of the ultrasonic sensor 2 when transmitting waves. 4 is an amplifier and filter that is an amplification circuit that amplifies the output from the ultrasonic sensor during reception, 5 is an A/D conversion circuit, and 6 is digitally converted by the A/D conversion circuit 5. 7 is a data processing means for recognizing the target object 14 from the reflected wave data in the memory 6; 9 is an address calculator for calculating the address of the reflected wave data in the memory 6; 10 is an initial value correction circuit for correcting the initial value (starting address) of the address of the address calculator 9, and 13 is a temperature sensor (temperature detection means) for detecting the ambient temperature.

In the ultrasonic object recognition device having the above configuration, a burst wave is generated in the transmitting circuit 1 and transmitted from the ultrasonic sensor 2 to the target object 1.
4, ultrasonic waves are irradiated (transmitted).

After this ultrasonic irradiation, the resonance suppression circuit 3 operates to suppress the vibration of the ultrasonic sensor 2, and after the vibration is sufficiently attenuated, the reflected wave from the target object 14 is received by the same ultrasonic sensor 2. do. Since this received signal is minute, it is amplified by an amplifier 4 and then input to an A/D conversion circuit 5 where it is converted into a digital signal 8. The converted digital signal 8 is stored in the memory 6 according to the address 12 calculated by the address calculator 9.

On the other hand, the initial value correction circuit 10 is configured such that the address of the reflected wave data stored in the memory 6 does not change depending on the temperature.
The initial value 11 of that address is calculated. For example, as shown in FIG. 2, when the temperature is relatively high, the initial value of the address of the reflected wave data stored in the memory 6 is a.
((a) in the same figure), and the initial value of the address of the reflected wave data when the temperature is relatively low is aa ((b) in the same figure, al
(a,) In this way, the address of the reflected wave data in the memory 6 changes depending on the temperature.

Therefore, the temperature is detected by the temperature sensor 13 and inputted to the initial value correction circuit 10. If the input temperature is high, the initial value 11 of the address of the reflected wave data is decreased, and if the temperature is low, the initial value 11 is increased. The initial value 1 so that
1 is corrected by an initial value correction circuit 10 so that the initial value 11 becomes constant. For example, the temperature is t, and the initial value 11 is a. Then, a. = α to 10 β In the arithmetic expression (1), the initial value 11 is calculated by appropriately selecting constants α and β in advance.

This initial value 11 is input to the address calculator 9 to calculate the address of the reflected wave data in the memory 6, and is output to the memory 6. However, the initial value 11 is changed depending on the address fluctuation due to the temperature change mentioned above. Its size changes (
(1)) Therefore, the reflected wave data is always at a substantially fixed position in the memory 6, for example, as shown in FIG. 2(c), the initial value a2
It is stored at the position (a, <a2<a,). Then, the target object 14 is electrically recognized by the data processing means 7 from the reflected wave data in the memory 6.

In this way, if the temperature is relatively high, the initial value of the reflected wave data will be small (for example, a), so the initial value a0 to be corrected is made thicker (see equation (1)), If it is low, the initial value of the reflected wave data will be large (for example, a
3), the initial value a to be corrected. By reducing , the reflected wave data is stored at a substantially fixed position in the memory 6 (for example, at the position of the initial value a2).

[Effects of the Invention] As explained above, according to the present invention, the initial value of the address calculator is corrected in accordance with changes in temperature, and the reflected wave data is stored in a substantially fixed position in the memory. Therefore, there is no need to search for reflected wave data in the memory as in the conventional method, and the speed of object recognition can be improved.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention, and FIGS. 2(a) and 2(c) are explanatory diagrams showing the storage location of reflected wave data in the memory. 1... Transmission circuit; 2...Ultrasonic sensor, 4...Amplification circuit, 5...A/D conversion circuit, 6...Storage device (memory), 7...Data processing means, 9...Address calculator,
1°...Initial value correction means, 13...Temperature detection means (temperature sensor).

Claims (1)

[Claims] At least a transmitting circuit that generates a burst wave, an ultrasonic sensor that transmits ultrasonic waves to a target object and receives ultrasonic waves reflected from the target object, and an amplifier circuit that amplifies the output from the sensor; an A/D conversion circuit that generates reflected wave data from the output of the amplifier circuit;
a storage device that stores reflected wave data from the D conversion circuit;
An ultrasonic object comprising: an address calculator for calculating an address for storing the reflected wave data in the storage device; and a data processing means for processing the reflected wave data in the storage device to recognize the target object. The recognition device includes: temperature detection means for detecting air temperature; and initial value correction for correcting the initial value of the address calculator based on the detection result of the temperature detection means so that the storage position of the reflected wave data does not change. An ultrasonic object recognition device characterized by comprising means.