JPS61142486A - Obstacle detector for vehicle - Google Patents

Abstract

PURPOSE:To enable quick detection with a high accuracy, by providing an emission rate altering means to switch the pulse signal emitted from a transmission means to the smaller emission rate receiving an emission rate alteration signal. CONSTITUTION:At the step 1005, it is judged whether as alarm signal exists or not. When no alarm signal exists, the step shifts to 1006 and TR is read out from a random number table. When the alarm signal is detected, the step shifts to 1007, there TR is read out from the random number table while multiplied by a specified value (for example, 0.5) to switch the pulse signal to the smaller rate. In this manner, when a vehicle is far away from an obstacle, a pulse signal is emitted at a large emission rate while it approaches the obstacle, the pulse signal is emitted at a small emission rate. This can reduce the time required for the detection of the obstacle thereby enabling quick detection with a high accuracy.

Description

[Detailed description of the invention]

[I! 1 Field of Application J of Tojo The present invention relates to an obstacle detection device mounted on a vehicle and used for detecting obstacles, etc. [Prior Art] Recently, in order to ensure the safety of vehicle driving, six vehicle bodies have been introduced.
Systems are being developed that are capable of detecting nearby obstacles using calculation means such as microcomputers as well as placing seven sensors on the body part.
As a prior art related to this type of system, JP-A-57-
There is one shown in Japanese Patent No. 168178. This device is specifically proposed as a back-up sonar for cars, and its basic operating principle is that a transmitter installed on the rear bumper emits ultrasonic pulses, and a receiver hits an obstacle. The reflected wave is received and the reflector width time is calculated by a microcomputer.
It is designed to detect the distance to obstacles, etc. Problems that tS Ming attempts to solve] However, according to such conventional obstacle detection devices,
Since the 2-channel transmitter not only senses the reflected wave of the pulse signal emitted from its own transmitter, but also the system signal, there is a problem that it is easily activated by interference signals and lacks reliability. Ta. In addition, in such conventional devices, the propagation time of the emitted pulse is estimated in advance based on the maximum detectable min, and the next pulse is waited until the propagation time has elapsed. Another problem is that the interval between pulses cannot be shortened and detection takes time, which can lead to a delayed warning and a collision, especially when an obstacle is approaching the vehicle. [Means for Solving the Problems] The present invention has been made to solve the problems of the conventional art and to provide an obstacle detection device with high V creativity. a transmitting means for detecting and receiving a pulse signal; and a receiving means for sensing and receiving a pulse signal, and one pair for each pulse signal emitted 5 times! storage means for storing received wave data defined by corresponding row addresses and column addresses corresponding to virtual reflection propagation times; The received wave data stored in the storage means is retrieved, the array is referred to, and the received pulse signals present at each row address in the received wave data are determined to indicate the movement of the vehicle! When it is confirmed that the data group is included as a series of data groups shifted in one direction at a constant rate according to Calculating means that calculates the distance from the vehicle to the obstacle based on the determined group of effective reflected pulses, and outputs a firing rate change signal when the calculated distance reaches a predetermined value;
The apparatus is characterized in that it includes a firing rate changing means that receives the firing rate changing signal and switches the firing rate of the pulse signal emitted from the transmitting means to a smaller one.

[Effect]

According to the RWL of the present invention, the pulse signal sensed by the receiving means is stored in the storage means for each emitted pulse signal.
is stored as received wave data defined by the row address corresponding to f
fl[The calculating means reads out the received wave data stored in the storage means, and refers to the array of the read out 52 @ wave data to find out whether the received pulse signals existing at each row address in the received wave data are the same as those of the vehicle. When it is confirmed that the data is contained in a series of data groups shifted in one direction at a constant rate according to the moving speed, the data group is determined to be a valid reflected pulse group and the presence or absence of an obstacle is detected are doing. Therefore, according to this detection device, even if the receiving means detects an interference signal other than the reflected wave of an obstacle, it is determined at the time of readout, thereby reliably eliminating the influence of interference signals emitted by nearby vehicles, etc. can do. Further, the firing rate changing means is actuated when receiving a firing rate changing signal outputted from the calculation means when the distance to the obstacle is less than a predetermined value, and the firing rate of the pulse signal is emitted from the transmitting means. Since the distance between the vehicle and an obstacle becomes shorter, it is possible to measure the distance between the two with high accuracy, effectively preventing the vehicle from colliding with the obstacle. There are advantages to S. [Embodiment] An embodiment of the present invention will be described below with reference to the drawings. The rs1 diagram is a correspondence diagram of the device of the present invention, in which 1 is a transmitting means, 2 is a receiving means, 3 is a calculation means, 4 is a storage means, and 5
indicates a means for changing the pulse firing rate. Fig. ff12 is a block diagram showing the configuration of Fig. 1 in more detail, and the transmitting means 1 is mainly composed of the ultrasonic transmitter 11, and the receiving means 2 receives the wave B! ! 9
411 have been constructed mainly from. Further, calculation means 3.
The storage means 4 and the pulse emission rate changing means 5 are mainly constituted by a microcomputer 12, and the storage means 4 is constituted by a RAM 4 within the microcomputer 12. The transmitting means 1 outputs a pulse signal of a predetermined frequency (for example, toKHz) based on the ultrasonic JA@ device 11.
It is equipped with an A oscillator 17 and a timer (#2) 6 that receives control signals from the microcomputer 12 and outputs pulse signals randomly at irregular intervals, and sends each of these outputs to a gate circuit (AND gate) 7. Further, the output from this gate circuit 7 is sent to the ultrasonic transmitter 1 via an amplifier 8.
1, and the timer (#
2) Ultrasonic pulses are sequentially emitted every time 6 outputs a pulse signal. Further, the receiving means 2 includes an ultrasonic receiver 9 and a comparator 10t-
The sensed pulse signal is passed through the amplifier 15 to the comparator! 0, and only reflected pulses above a certain level are received. In addition, the ultrasonic transmission s11 and the ultrasonic 9 transmission! Reference numeral 19 is arranged at an appropriate position on the vehicle body facing the forward or reverse direction of the vehicle. On the other hand, the M calculation means 3 includes a timer (#1) 18 and the timer (#2) 8 in an ordinary microcomputer 12 which is a combination of a CPU 13, a ROM 14, a RAM 4 constituting a storage means, and an I10 port (not shown). It is made by combining. Such a microcomputer 12 already installed in the vehicle can be used for multiple purposes. Next, the operating procedure of this detection device will be explained with reference to the 31st flowchart. The program is composed of routine A, routine B, and routine C. Routine A consists of a pulse signal emission routine 100 and a transmission wave table creation routine 101, in which the transmission means 1 is operated at a predetermined time interval T-, and the emission rate Ta (pulse signal emission time fIR interval) is determined. ) are sequentially emitted at random, and at the same time the emission time TI of the pulse signals is written in the RAM 4 to create a transmission wave data table T (1). Routine B consists of a pulse signal reception routine 102 and a received wave table creation routine 103, and defines the pulse signal sensed by the receiving means 2 by a row address l and a column address according to the virtual reflection propagation time Tb. It is received as the received wave data and stored in the RAMA as the received wave data table TD (i, Tb (d)).
Create. Here, the row address 5 is a number corresponding to the pulse signal emitted from the transmitting means 1-, and Th (
d) is determined based on the time point at which the pulse signal emitted from the transmitting means l is reflected, assuming that the sensed pulse signal is a reflected signal emitted from the transmitting means l. Further, the routine C includes the reading routine CI of the received wave data table TD (1, 7b (d)) created above and the read received wave data table TD (1, 7b (d)).
Based on the array pattern of Tb(d)), the reflected wave from the obstacle (hereinafter referred to as effective reflected pulse) is composed of a received wave data array pattern determination routine C2 for determining an effective reflected pulse. Note that the routine AcF) While routine B is being executed, routine B is interruptible, but while routine C is being executed, the execution of routines A and E is interrupted. Each routine will be explained below. In routine A, first, in step 1001, all fis of the received wave data table TD (t, Tb (d)) are
Clear the data written in #1 and proceed to step 100
2, the number tea of the pulse signal first emitted from the transmitting means l is set, and T(0) is written in the 0th row # of the transmission wave data table together with its emission time TI. Next, in step 1003, the olIIth pulse signal is emitted and the timer 16 (#1) is set. The value is set to 1-0, and the process proceeds to step 1004, where l is incremented. Then, in step 1005, it is determined whether or not there is an alarm signal, and if there is no alarm signal, the process proceeds to step 100B, where TI is read from the random number table, but when a %'1 alarm signal is detected, the process proceeds to step 1007. In step 1007, Ta is derived from a random number chain, and Tm is set to a predetermined value α (for example, 0.
5) to switch the emission rate of the pulse signal to a smaller one. In step 1008, the operating time of the timer (#2) is set based on the read Tl, and in step 10
In 09, the firing time TI of the 3 A pulse is calculated based on the operation time of the set timer (#2) 8. Initially, it is calculated based on the firing time of the 0th pulse), In step 1010, it is determined whether t>Tm and whether a predetermined time Tll has elapsed after emitting the ofIith pulse. Proceeding to step 1011, a primary pulse signal is emitted. And step 10
In step 12, t > T p is n1lL. If so, proceed to step 1013 and interrupt the routine B, but if not, return to step 1004, increment l, and proceed to steps 1005 to 101.
0 and emits the next pulse signal (see Fig. 4). Thus, after the O-th pulse ° signal is emitted, at a time interval until a predetermined time T- has elapsed, the pulse signal is sequentially emitted from the transmitting means l at a random emitting routine (TI) read from the random number table. At the same time, the number l and the emission time T of the emitted pulse signal are
(i) is stored in the RAM 4, and a transmitted wave data table T (1) as shown in FIG. 8 is created. In addition, the one in FIG. 8 is during one hour interval Tm. An example is shown in which six pulse signals are emitted. Needless to say, as the number increases to 7.8A, the number of 1s in the transmission wave data table increases. On the other hand, in routine B including sI, all pulse signals sensed by the receiving means 2 are given one row address l and virtual reflector width time II.
A column address d corresponding to IIT* is defined, and a received wave data table Tn (1, T> (d)) is created. That is, in step 2000, the reception time t of the pulse signal sensed by the receiving means 2 is read, and in step 2001, the virtual reflection propagation time T- of the sensed pulse signal is calculated, and in step 2002, the received wave data Write 1 to the corresponding address of the table TD (1, T-(d)), receive wave data table TD (1, T
In b (d)), when there is no sensed pulse, O is written to the corresponding address. Here, the first row address i is assigned a number corresponding to the pulse @ emitted from the transmitting means l, and the virtual reflection propagation time Tb indicates that the pulse signal sensed by the receiving means 2 is the same as the transmitting means! It is calculated as the body width time assuming that the pulse signal is a reflected pulse of a pulse signal emitted from the center. Next, in step 2003, it is determined that d>d, and if it is likely that d>d, the process proceeds to step 2004 and l is incremented. Then, in step z005, it is determined whether l has reached the maximum row 1* of the received wave data table τD (1, TI (d)), and if i has reached IN,
In step 2006, reception of the pulse signal by the receiving means 2 is stopped and l is set to O (see Figure !85). As a result, in routine B, the pulse signal sensed by the receiving means 2 is read into the RAMA in a manner unaffected by the firing rate T, and the received wave data table TD (1, TI (d)) will be created. On the other hand, when routine A reaches step 1013, interrupts of routine B are prohibited and the process proceeds to routine C. Therefore, while routine C is being executed, the execution of routines A and H described in TI is interrupted. , received wave data table TD (1, Tb
The reading in (d)) is executed to determine the presence or absence of an obstacle. That is, in routine C1. In step 4000, all # of the pi signal data table TD (i, Th (d)) are set to dMo.
The first three lines to be read from the beginning are the A address set to 0°0, and in step 4001, the ##! ! T.D.
It is determined whether the data at (0, O) is 0 or not. Steps 4001-4002-4003 are then cycled through, and if no received wave data is found in all columns #81 in row 0 of the received wave data table TD (i. Tb(d)), a failure is detected. It is determined that there is no item and the process proceeds to step 40G4 to display the fact. Therefore, steps 4001-4002-4003
When received wave data is detected at any column address of the 0th row address by cycling through the steps 4005-4006
-4007 to read all rows of data. As a result, the received wave data table TD(t, Tb
(d) Data written in all rows at address 1 in (d)) is read out. On the other hand, in the array pattern determination routine c2, it is determined whether or not the read received wave data table TD (1,7*(d)) includes an effective reflected pulse. This discrimination can be easily performed when the vehicle is stationary by synchronously adding the information written in the received wave data table TD ([, Tb(d)).
In order to detect the presence or absence of obstacles, including when the vehicle is moving, sL:i signal wave data table TD (1°T
This is possible by referring to the arrangement pattern of the pi signal data written in 111 in b(d)). That is, if we consider the time when the vehicle is moving now, in such a case, the data table TD(1, Th (d
) J is likely to contain an effective reflected pulse, the received wave pulse signal rlJ present at each row address of the data table TD (1, 7 * (d)) will be uniform at a constant rate according to the moving speed of the vehicle. This means that the array is shifted in the direction. If not, please read the received wave data table TD (
1, Tb (d)) array bar II-y is ffll
When it is like the one shown in the figure o, the series of received wave data "1" included in the white arrow tends to shift to the left at a certain rate, so it is judged to be an effective reflected pulse group, and there is no obstruction. This means that it is considered to be detecting the FIG. 7 shows a flowchart of such received wave data array pattern determination routine C2, in which steps Step 3
At step 000, the maximum speed vII is first determined as the moving speed of the vehicle, and at step 3001, the array pattern of the received wave data table TD (i, Ts (d)) is referred to. As a result of this array reference, the received wave data table T
If there is no dextral reflex pulse group within D (1, Tb(d)) that is shifted in one direction by a certain percentage according to the maximum speed VH, the process advances to step 3003 and the speed V is gradually increased. Reduce the received wave data table TD (
i, Tb (d)), but 4
Such pattern reference is carried out in step 3003 until the speed V reaches the negative maximum speed -2. Then, the effective reflected pulse group corresponding to the speed assumed in step 3002 is expressed in the data table TD (I, Tb
, (d)), the process proceeds to step 3006, where a signal for detecting the obstacle is issued, and the speed V assumed at the time of the discovery is determined as the actual relative speed between the vehicle and the obstacle. At the same time, the distance to the obstacle is calculated based on the virtual reflection propagation time T- written in the data table TD (1, Tb (d)). Furthermore, after calculating D, the required vehicle moving speed V and the calculated distances II & D to the obstacle are displayed. Furthermore, as a result of all the pattern references of one or more received wave data tables TD (l. Tb (d)), if no effective reflection pulse group corresponding to the assumed speed is detected, it is determined that there is no obstacle. It is. In step 3005, this information is displayed on the display. On the other hand, it is determined that there is an obstacle and step 3006
When the process proceeds to step 3007, a message to that effect is displayed on the display device, and the distance RID is calculated in step 3007.
The process proceeds to 0B, and it is determined whether the distance is less than or equal to a predetermined value D. Then, when the distance becomes less than the required value D,
The pulse signal emission rate changing means 5 activates the alarm means to generate an alarm signal to notify that the vehicle is abnormally close to an obstacle (for example, approaching less than 1.5 m).
is activated to switch the emission rate of the pulse signal emitted from the transmitting means l to a smaller one. Specifically, the firing rate is changed from an average of 20+gec to an average of 101 seconds. As a result, when the vehicle approaches the obstacle to a predetermined distance, the pulse signal emitted from the transmitting means 1 has a lower emission rate, and according to the same operating procedure as described above,
The distance to the l1g book will be displayed moment by moment. FIG. 11 shows such an arrangement pattern determination routine C2.
is a diagram showing the relationship between the assumed moving speed V of the vehicle and the array pattern of the effective reflected pulse group, where i1 degree is V
-Ol, that is, when the vehicle is stationary, the effective reflected pulse group is not shifted and is vertically -I! Although it is arranged in a linear manner,
As the moving speed V increases in the positive direction (closer to the obstacle), the effective reflected pulse increases as shown in the data table TD (
1゜Tb(d)) exhibits an arrangement shifted in the direction of smaller row addresses at a rate corresponding to the moving speed V. Conversely, the moving speed V increases in the negative direction (direction moving away from the obstacle). , the effective reflected pulse is given by data table TD
It will be understood that the row address of ←i, Ts(d)) is shifted in the direction of the larger row address at a rate corresponding to the moving speed V. Note that the transmitting means l in the present invention is not limited to one in which the firing rate is random, but may be one that fires at a constant firing rate, but if the number of vehicles that emit pulse signals at regular intervals increases. Since there is a risk of interference with each other, it is desirable to emit them randomly. [Effects of the Invention] Since the present invention includes one or more of the above configurations, it is possible to provide an obstacle detection device for use in a vehicle that is not affected by interference signals, is accurate, and has a high level of focus. Gade S Ru again. A group of pulse signals emitted from the transmitting means is
There is no need to emit pulse signals at a pulse interval that takes into account the reflection method width time assuming the maximum IL range that can be detected by OT, and when the vehicle is far from the obstacle, the pulse signal is emitted at a high firing rate to reach the obstacle. When approaching, pulse signals can be emitted at a low firing rate, so there is no wasted time to detect obstacles, and the time required to detect obstacles can be significantly reduced, allowing rapid and highly accurate detection. 4 A brief explanation of the drawings: WS1 is a claim correspondence diagram of the device of the present invention, FIG. 2 is a block diagram showing the configuration of the final rI3 device, and t! Figure S3 is a flowchart for explaining the operating principle of the device of the present invention;
FIG. 4 is a flowchart of the pulse signal emission routine, FIG. 5 is a 70-chart of the pulse signal reception routine, and FIG.
754 is a flowchart of a routine for reading the reception wave data table, FIG. 8 is a flowchart of a routine for determining the arrangement pattern of reception wave data, and FIG. FIG. 9 is an example of the received wave data table, Shima 10v4 is an explanatory diagram of the principle of determining the array pattern of the received wave data table, and FIG. 11 is a diagram showing the vehicle movement 4! in the received wave data table. & It is an explanatory diagram of the arrangement pattern when the speed is changed. 1. Transmitting means 2... Receiving means 3... Calculating means 4... Memory child actor 5, φ, firing rate changing means

Claims (2)

[Claims] (1) A transmitting means for sequentially emitting a group of pulse signals, a receiving means for sensing and receiving the pulse signals, and a pulse signal sensed by the receiving means is transmitted to each emitted pulse signal.
A storage means for storing received wave data defined by a pair-one corresponding row address and a column address according to a virtual reflection propagation time, and a storage means for reading the received wave data stored in this storage means and referring to the arrangement thereof. When it is confirmed that the received pulse signals existing at each row address are included in the received wave data as a series of data groups shifted in one direction at a constant rate according to the moving speed between the vehicles, the data is The system determines the group as an effective reflected pulse group and detects the presence or absence of an obstacle, calculates the distance from the vehicle to the obstacle based on the determined effective reflected pulse group, and when the calculated distance reaches a predetermined value. It is characterized by comprising a calculation means for outputting a firing rate change signal, and a firing rate changing means for switching the firing rate of the pulse signal emitted from the transmitting means to a smaller one in response to the firing rate changing signal. Obstacle detection device for vehicles. (2) The vehicle obstacle detection device according to claim 1, wherein the transmitting means is configured to sequentially emit pulse signals at random time intervals.