JP2009265010A - Object recognition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a predetermined object existing in a detectable region without generating a beam or sweeping the beam. <P>SOLUTION: Reflection wave detection circuits 32a, 32b, ..., 32h output a value of "1" to delay circuits 44a, 44b, ..., 44h, respectively when a top position of a reflection wave is detected. Shift registers 41a to 41h on a receiving side sequentially shift values output from the delay circuits 44a to 44h in accordance with a transmission clock signal. In the case where a reflection signal from a vehicle is received, it is assured that a value of "1" indicative of the top with respect to reflection from one of a plurality of positions representing a boundary of a body of the vehicle, resides in a specific register (stage) in a shift register 41i on the transmission side and the shift registers 41a to 41h of each of receivers 1a to 1h. An AND-circuit 423 detects that all or most of the registers have the value of "1" so that the body of the vehicle is recognized. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an object recognition apparatus that recognizes the shape of an object existing in a detection area using ultrasonic waves or the like.

  A conventional object detection apparatus using ultrasonic waves measures a time from when an ultrasonic pulse is transmitted to when a reflected wave is received by a pair of transceivers.

  A conventional object detection device that measures the time from transmitting an ultrasonic pulse to receiving a reflected wave with a pair of transceivers can measure the distance to the reflecting object, but the direction is not known. , Can not locate.

  Also, in an ultrasonic echo diagnostic device, etc., signals from a large number of receiving sensors arranged in an array are added by controlling the time difference or phase difference to give directivity (beam) in a specific direction. An image is obtained by scanning the beam. Since this method requires scanning the beam, it takes time to scan the whole, and the whole picture is not known until the whole scan is complete, and the information obtained from the beam scan must be reconstructed. There is a problem that must be. Furthermore, since the above processing is very complicated, there is a problem that it is difficult to reduce the cost.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an object recognition apparatus which can recognize a predetermined object without forming a beam and scanning the object existing in the detection area.

  For example, it is possible to determine whether or not the vehicle collides with an object that reflects ultrasonic waves (walls, standing trees, curbs, etc.), taking into account the body shape of the vehicle, or in darkness like a kite Thus, it is possible to know the position of the wall surface of the cave by ultrasonic waves and to fly without colliding.

  In order to solve the above problems, an object recognition apparatus according to the present invention is first configured as follows. An ultrasonic transmitter for detection, a receiver arranged in an array for receiving a reflection signal generated by reflection of a transmission signal from the transmitter by an object existing in a detection region, and a reception signal by the receiver Alternatively, one shift register is prepared for one receiver that sequentially inputs the converted data as time series data.

  Next, an AND circuit for detecting that a signal has reached all or most of a plurality of specific positions of the plurality of shift registers having this configuration is prepared, and an object is present at a position of the specific positions. In accordance with the arrival time of the reflected wave, if an object exists at that position and the ultrasonic wave is reflected, the output of this and circuit becomes “1”. By providing an AND circuit for a plurality of positions representing the boundary of the automobile body and detecting that one of them outputs “1”, the object is about to collide with the automobile body. I understand that.

  In order to increase the resolution of position detection, it is necessary to handle a smaller time difference, and it is necessary to increase the transfer speed of the shift register, that is, the frequency of the shift clock. If the frequency of the shift clock is increased, the total time that can be handled is reduced with the same number of stages. Therefore, if the detection range is not changed, the number of stages of the shift register must be increased in proportion to the frequency of the shift clock. On the other hand, in order to widen the detection range, it is necessary to handle a larger time interval, and the number of shift register stages must be increased. Therefore, both the increase in resolution and the detection range lead to an increase in the number of shift register stages.

  Therefore, a mechanism that makes the frequency of the transfer clock of the shift register variable and inserts a variable number of FIFOs between the receiving sensor and the shift register so that the first half of the shift register is replaced with the FIFO to suppress an increase in hardware due to the shift register. Provide. Since the FIFO can be realized by a 2-port RAM or the like, the amount of hardware can be greatly reduced compared to the shift register. In this configuration, first, the shift register bears the entire detection range in a state where the resolution is small, and first, it is detected at which position the reflecting object is present. Next, it can be used to increase the resolution and acquire detailed information for an object in a critical (interesting) area.

  According to the present invention, reflected waves from a plurality of directions can be detected directly including a distance without scanning the beam, and high-speed recognition is possible. In addition, since it has a simple architecture and a regular configuration, it is suitable for hardware and can be expected to operate with low power consumption. In addition, it is possible to perform an adaptive operation such as detecting a position with an increased resolution with respect to a target to which attention is directed.

  FIG. 1 is an overall block diagram of an object recognition apparatus 100 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an arrangement example of a transmitter and a receiver and a state in which ultrasonic waves are reflected by an object and received.

  In this example, as shown in FIG. 2, receivers 1 a to 1 h are arranged in an array around the transmitter 11. In FIG. 1, a burst signal generator 12 generates a burst signal at a transmission timing, and a burst signal (electric signal) output from the burst signal generator 12 is converted into an ultrasonic wave by the transmitter 11 and is detected in the detection area. Radiated toward the object. The receivers 1a, 1b,... 1h convert the ultrasonic waves reflected by the object into electric signals. The reflected wave detection circuits 32a, 32b,... 32h calculate the correlation with the transmission signal, and set the time series data to “1” when the head position of the reflected wave is detected and “0” otherwise. This is output to the delay circuits 44a, 44b,... 44h. When multiple heads of reflected waves arrive due to the shape or number of objects, “1” is output each time.

  The delay circuits 44a, 44b,... 44h are FIFO delay circuits composed of a 2-port RAM or the like, and after delaying by a time corresponding to the number of stages and the frequency of the clock signal, the shift registers 41a, 41b,. Input to 41h.

  The clock signal generator 43 provides a transfer clock signal to the shift registers 41a to 41i.

  The values output from the delay circuits 44a to 44h are input to the shift registers 41a to 41h on the receiving side. A signal from the burst signal generator 12 is input to the shift register 41i on the transmission side via the delay circuit 44i. In other words, “1” is sequentially input to the shift register 41 i on the transmission side, and “0” is sequentially input at the leading position of the burst signal. These shift registers 41a to 41i sequentially shift the contents in synchronization with the transfer clock signal.

  The control unit 5 gives a burst signal generation timing signal or its cycle control signal to the burst signal generator 12, gives a clock signal frequency control signal to the clock signal generator 43, and gives the delay circuits 44a to 44i the number of stages of the delay circuit. A control signal, that is, a delay time control signal is provided. Further, the control unit 5 gives a control signal for selecting which AND circuit to be effective to an AND circuit 423 described later.

  When the burst signal period is less than the distance resolution and a sufficient S / N ratio is obtained, the reflected wave detection circuits 32a, 32b,... 32h can be omitted. That is, the output signals of the receivers 1a, 1b,... 1h may be binarized into logic level signals and supplied to the delay circuits 44a, 44b,.

  First, the control unit 5 sets both the delay circuit 44i on the transmission side and the delay circuits 44a to 44h on the reception side to 0 stage, that is, “delay time = 0”, and the clock signal generator 43 receives the received signal from the search range. A clock signal having a sufficiently low frequency is supplied so that (the conversion signal) just fits in the shift registers 41a to 41i. In such a state, the “1” signal indicating the head position and the “0” signal not so are sequentially shifted to the subsequent stage.

  When a reflected signal is received from one of a plurality of positions representing the boundary of the body of the automobile, “1” representing the head is a shift register 41 i on the transmission side and shift registers 41 a to 41 h for each of the receivers 1 a to 1 h. It exists in a specific register (stage) of 41h. Therefore, when the AND circuit 423 detects that “1” is present in all or most of these registers, it can be seen that an object is present at this one position that represents the boundary of the body of the automobile. The AND circuit 423 corresponds to “reflection position specifying means” according to the present invention. Such a circuit is also prepared for other positions representing the boundary of the body of the automobile, and if the or circuit 424 detects that there is an output from any of these, an object touches the body of the automobile. I understand that I am trying.

  A plurality of sets of the AND circuits 423 are provided according to the transfer clock frequency of the shift register. That is, the transfer clock frequency of the shift register is switched by distance resolution (resolution of the reflection position to be detected), and an AND circuit to be used is selected according to the switching.

  Thereafter, in order to increase the distance resolution, the control unit 5 increases the frequency of the clock signal generated by the clock signal generator 43, and thereby causes the delay circuits 44a to 44i to take over the number of shift register stages that are insufficient. In addition, the number of FIFO stages of the delay circuits 44a to 44i is set to a predetermined number. The number of stages of the delay circuit is determined so that conversion data of the received signal in a predetermined time range after a predetermined time from the generation of the burst signal is developed in the shift register. By using the delay circuit in this way, an increase in hardware due to the shift register can be suppressed, and the entire amount of hardware can be greatly reduced.

  Further, the control unit 5 selects an AND circuit corresponding to the distance resolution from the AND circuit 423.

  In this way, first, the shift register is responsible for the entire detection range with a low resolution, detects where the reflective object is present, and then, in a relatively narrow area including the approximate position. On the other hand, detection is performed with the resolution increased. In this way, by increasing the resolution stepwise, detailed information of the reflecting object is acquired in a short time. The control unit 5, the clock signal generator 43, and the delay circuit 44 that perform the resolution control correspond to the “position resolution control means” according to the present invention.

  The AND circuit 423 is not provided with an AND circuit that inputs only the output of the stage of the shift register corresponding to the position representing the boundary of the body of the automobile, but inputs the output signals of all the stages of the shift register, It may be configured to determine which stage of the output signal is valid by the “detection validation input bit”. That is, the “detection validation input bit” is set to “1” for the output signal from the stage corresponding to the position representing the boundary of the body of the automobile. As a result, all the AND circuits have the same hardware configuration, which simplifies the circuit and enables high-speed operation.

  In each of the embodiments described above, the ultrasonic signal is used as the detection signal, but light waves and radio waves may be used as the detection signal in the same manner.

  In addition, not only when the detection transmission signal receives a reflection signal due to reflection by an object existing in the detection area, but also when an object existing in the detection area passively radiates sound waves, light waves, radio waves, etc. You may apply this invention. That is, when distance measurement of an object is unnecessary, a signal emitted from an object existing in the detection area may be directly received and the received signal may be used as detection data.

It is a figure which shows the structure of the object recognition apparatus which concerns on embodiment of this invention. It is a figure which shows the example of arrangement | positioning of the transmitter and receiver in the apparatus, and a mode that an ultrasonic wave is reflected and received by an object.

Explanation of symbols

1a, 1b ... 1h ... receiver 11 ... transmitter 12 ... burst signal generator 32a, 32b ... 32h ... reflected wave detection circuit 41a, 41b ... 41h, 41i ... shift register 43 ... clock signal generator 44a, 44b ... 44h, 44i ... delay circuit 100 ... object recognition device 421 ... comparison circuit 422 ... reference data storage unit 423 ... and circuit 424 ... or circuit

Claims (3)

  A transmitter for transmitting a detection signal; a receiver for receiving a reflection signal generated by reflection of the detection signal by an object existing in a detection region; and a reception signal by the receiver; or A shift register that sequentially inputs the converted data as time-series data, and whether or not the received signal or the converted data arrives at a predetermined position on the shift register to identify the reflection position of the detection signal An object recognition apparatus comprising: a reflection position specifying unit.   The object recognition apparatus according to claim 1, further comprising position resolution control means for controlling a position resolution for specifying a reflection position of the detection signal by controlling a frequency of a transfer clock of the shift register.   The object recognition apparatus according to claim 1, wherein a FIFO delay circuit having a variable number of stages is provided between the receiver and an input of the shift register.

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