JP2501540Y2 - Vehicle movement detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a vehicle movement detection device, and more particularly to a device that detects a start of a vehicle ahead and issues an alarm.

[Conventional technology]

Even if the vehicle immediately in front of your own vehicle (hereinafter referred to as the front vehicle) starts when the signal changes or the traffic advances forward during a temporary stop due to a signal, or during a temporary stop due to a traffic jam, etc. Drivers often overlook this. This is often seen especially when the driver is very tired, during a conversation in a car, operating a radio / audio, or performing business such as form work in a car for business use in the car.

In such a case, when the driver notices this due to a warning sound from the following vehicle, the distance between the vehicle ahead and the vehicle ahead is wide, and thus sudden start / acceleration is required. As a result, the safety confirmation at the time of starting is neglected, the driver of the following vehicle is annoyed, and the synergistic action of these causes a great loss of safety, fuel economy is deteriorated, and traffic flow is disturbed.

From such a point of view, a device for issuing an alarm when a vehicle ahead has started has already been proposed as shown below.

Japanese Utility Model Laid-Open No. 61-195487: Doppler type ultrasonic detector is attached to the front part of the vehicle body, and it is determined from the output of this detector that the preceding vehicle has moved in the separating direction and a start reminder is issued. Front departure vehicle detection device.

Japanese Utility Model Laid-Open No. 63-89200: Distance between the front vehicle and the front vehicle is detected by measuring the distance between the front vehicle and the front vehicle when the vehicle speed is zero and the vehicle is stopped. Inter-vehicle distance detection device that triggers an alarm.

Gazette of Japanese Utility Model Laid-Open No. 63-97200: The distance between the own vehicle and another vehicle or an obstacle is measured by using an ultrasonic transmitting / receiving element, and the distance data of the previous time is compared with the distance data of this time to make a difference between the data. A vehicle movement detection device that issues an alarm when the vehicle speed of the host vehicle is zero.

Japanese Utility Model Laid-Open No. 63-187083: Using an ultrasonic transmitter / receiver, the inter-vehicle distance proportional to the time between ultrasonic transmission and reception was measured, and it was detected that there was a difference compared with the stored inter-vehicle distance. At that time
An inter-vehicle distance change detection device that issues an alarm if the vehicle is in a stopped state (vehicle speed: zero, transmission: neutral, parking brake: activated) as if the vehicle is approaching or moving away from the vehicle in front.

[Problems to be solved by the device]

However, in any of the above conventional techniques, when a change in inter-vehicle distance occurs, an alarm is immediately issued under a certain condition, so that the preceding vehicle may start suddenly or suddenly regardless of this. Since the warning is frequently issued, it is very annoying and annoying to the driver, and there is a problem that many nerves must be devoted to driving in accordance with traffic conditions.

Therefore, an object of the present invention is to realize a vehicle movement detection device capable of issuing an appropriate warning according to road traffic conditions.

[Means for solving the problem]

In order to solve the above problems, the vehicle movement detection device according to the present invention includes an ultrasonic transmitter / receiver attached to the front of the vehicle, a means for detecting the stopped state of the own vehicle, and the transmission / reception when the stopped state is detected. The inter-vehicle distance between the front vehicle and the host vehicle is measured and calculated from the input / output of the device, and when the inter-vehicle distance is within a predetermined value, a signal indicating that the front vehicle is within the predetermined value is generated. After that, when the vehicle-to-vehicle distance sequentially reaches two predetermined values larger than the predetermined value within a predetermined time, a signal indicating the presence of the front vehicle is generated, and if the vehicle is stopped, the front vehicle starts. And a control means for calculating a starting acceleration during the period and activating the alarm output device corresponding to the acceleration.

Further, in the present invention, an ultrasonic transmitter / receiver attached to a front portion of the vehicle, a means for detecting a stopped state of the own vehicle, and an input / output of the transmitter / receiver when the stopped state is detected from the front vehicle and the own vehicle And calculates a vehicle-to-vehicle distance with the vehicle-to-vehicle distance, and when the vehicle-to-vehicle distance is within a predetermined value for a predetermined duration, generates a signal indicating that the preceding vehicle is within the predetermined value. A signal indicating the presence of the preceding vehicle is generated when two predetermined values larger than the predetermined value are sequentially reached for a predetermined duration, and a signal indicating that the preceding vehicle has started is generated in the stopped state. It is also possible to solve the above-mentioned object by providing a control means for calculating a starting acceleration during that time and activating the alarm output device in accordance with the acceleration.

Further, according to the present invention, the control means includes a start operation detecting means, and the control means does not require an alarm when the start operation detecting means detects the start operation even when the stop state detecting means detects the stop state. It is also possible to generate the indicated signal.

[Action]

According to the present invention, the control means controls the input / output from the control means to the ultrasonic transceiver mounted on the front part of the vehicle and the transmission / reception of the ultrasonic pulse by the reflection of the ultrasonic pulse when the stopped state of the vehicle is detected. The inter-vehicle distance between the front vehicle and the host vehicle is measured and calculated by the output to the means.

Then, when the calculated inter-vehicle distance is within a predetermined value, a signal indicating that the preceding vehicle is present immediately before the host vehicle is generated.

After this, the control means again determines that the inter-vehicle distance between the front vehicle and the host vehicle, which is obtained again by measurement and calculation, reaches two predetermined values, which are larger than the predetermined value, within the predetermined time in the stopped state. When a signal indicating is generated, the acceleration during that time is calculated.

By activating the alarm output device in accordance with this acceleration, it is possible to inform the driver of the own vehicle how the preceding vehicle has started, and thus to inform the road traffic situation.

Further, according to the present invention, an alarm can be issued as if the forward vehicle has started only when the same determination result is obtained for a predetermined period of time in each of the two-stage presence signal generation (determination) of the preceding vehicle. The unnecessary and troublesome alarm can be eliminated by eliminating the repetition of the establishment / non-establishment of the alarm condition within a certain determination time according to the traffic situation.

Further, even when the vehicle is stopped, when the start operation detecting means detects the start operation, it is supposed that the driver is gazing ahead, so no alarm is issued.

In this way, the two-stage determination is performed so that various troublesome unnecessary alarms are not sounded.

〔Example〕

FIG. 1 is a diagram showing a system configuration of a vehicle movement detection device according to the present invention. In FIG. 1, a 40 KHz ultrasonic pulse inaudible to the human ear is emitted to emit a pulse from an object. It is intended to detect the movement of a vehicle ahead by measuring and calculating the reflection reception time and converting it into a distance.

First, in FIG. 1 (A), 1a and 1b are vehicles as a target object, and 10 and 20 are ultrasonic type devices each having a transmission unit 2, an ultrasonic transmission element 3, an ultrasonic reception element 4, and a reception unit 5. A transceiver, 6 is a control unit, 7 is an alarm output device, 11 is a vehicle speed sensor, 12 is a parking brake switch, 13 is an accelerator pedal switch, 14 is a gear position sensor, and 15 is a brake pedal switch. still,
The switches 12, 13, 15 and the sensor 14 are shown by dotted lines to show that they are not indispensable as described later, and the vehicle speed sensor 11 may be replaced with the parking brake switch 12 as described later. it can. Also, although an example using two transceivers is shown, as will be described later,
One may be used, or three or more may be used.

Next, the operation will be described. First, an oscillation pulse control signal (see FIG. 1B) is sent from the control unit 6 to the transmitter 2 of the transceiver 10 via the signal line a. In response to this, the transmitter 2 receives 40
A pulse of KHz is generated, and the pulse is amplified to a level required to drive the transmitting element 3 and the optimum waveform shaping for driving the pulse is performed to drive the transmitting element 3 and emit an ultrasonic pulse.

The ultrasonic wave receiving element 4 receives the ultrasonic wave reflected by the object 1a and inputs it to the receiving unit 5, where it amplifies the received wave to an optimum level and smoothes it with a filter or the like. And digitized and returned to the control unit 6 via the signal line b as a received signal.

As shown in FIG. 1 (B), the control unit 6 measures the reflection time t (sec) from the output of the oscillation pulse control signal to the input of the received signal to measure the sound velocity (340 m / s20
The distance l to the object is calculated as l = 340 × t / 2 (m).

As will be described later, if no reception signal is detected within a certain time T, it is assumed that an object does not exist within a certain distance (340 × T / 2) from the corresponding sensor.

The control unit 6 receives the output signal from the transceiver 10 to calculate the distance, and then sends the oscillation pulse control signal to the transmitter 2 of the transceiver 20 in the same manner. Then, the distance 1 to the object 1b is similarly measured.

Measurement of this transceiver 10 → transceiver 20 → transceiver 10 ...
By repeating the output, it is possible to stably obtain the distance l between each transmitter and the receiver, and the mutual interference is prevented by alternately oscillating and receiving ultrasonic waves between the transmitters and receivers.

Therefore, here, two ultrasonic transceivers are connected to one control unit, but when there is one transceiver, only the input / output of that transceiver is used, and two or more ultrasonic transceivers are used. In this case, the control unit 6 uses only the output of the transmitter / receiver indicating the closest distance.

Further, although the description has been made by taking as an ultrasonic transmitter / receiver a transmitter and a receiver only, a transmitter / receiver integrated type is also possible. Also, various ultrasonic frequencies can be used.

Then, in the control unit 6, the transceivers 10, 20
The alarm output device 7 is energized to generate an alarm by using the distance data from the sensor and the output signals from the sensors or the switches 11 to 15 alone or in combination.

FIG. 2 is a schematic view of a mounting example and a detection range when the ultrasonic transmitter-receiver described in FIG. 1 is mounted on a vehicle.

That is, FIG. 3A shows an example of attachment to the front part of the vehicle. Vehicle width, depending on the mounting position
Since the detection range is limited by the distance from the road surface, angle adjustment / correction is performed as appropriate up / down / right / left.

FIG. 2B schematically shows the horizontal plane detection range, and the detection range x (m) corresponds to the vehicle type,
The detection range can be set by the user. still,
FIG. 3C shows a side view.

In FIG. 2 as well, two examples of mounting the ultrasonic transmitter / receiver are shown, but the number and mounting positions of the transmitter / receivers can be arbitrarily set according to the vehicle type and are not limited.

FIG. 3 schematically shows control conditions for the control unit 6 to activate the alarm output device 7 to generate an alarm according to the present invention. The system ON condition S1, the system setting condition S2 and the alarm are shown. Output condition S3 and alarm generation step S4
The alarm generation is reset when these conditions are not satisfied.

Incidentally, among these conditions, the system ON condition S1 does not necessarily have to pass through, and is shown by a dotted line.

For each condition step, the case where the start detection of the vehicle ahead is performed according to the present invention will be described.

(I) The system ON condition is a control that does not sound the alarm until the running state is detected at least once after the engine is started, and is conceptually illustrated in FIG. 4 (I). As described above, since the traveling state can be detected based on the vehicle speed, the alarm can be controlled based on this.

As a result, an alarm is generally unnecessary at the first start after the engine is started, and an unnecessary alarm that is offensive to the driver is prevented.

Incidentally, when a predetermined start switch (not shown) is set, the control of this system ON condition can be omitted by starting with this switch.

(II) As conceptually shown in FIG. 4 (II), the system setting condition is satisfied, when the vehicle ahead is detected within a certain distance (and time) in the stop detection state (and non-start operation detection state). This is the case when the presence is detected.

This is a state in which the driver needs a front vehicle start detection warning as a step before the front vehicle start detection, that is, the reference distance immediately before the own vehicle in the state where the driver can run or is stopped (stopped). This is a control for detecting a vehicle ahead in time.

At this time, when the start of the vehicle is detected, the alarm is not required and is reset (see FIG. 4 (I
V)).

(III) As the alarm output condition is satisfied, as conceptually shown in FIG. 4 (III), the vehicle stop detection state (and the non-start operation) is still present at two distances larger than the predetermined distance in the condition (II). This is the case where the preceding vehicle cannot be detected within the predetermined time in the detection state).

At this time, the acceleration by the two distances within the predetermined time is calculated, and an alarm is issued according to the calculated acceleration (S4).

That is, the alarm output condition (III) exists immediately before the own vehicle after satisfying the condition that the driver needs the forward vehicle start detection alarm in the system setting condition (II) in the previous stage. This is a method of detecting that the vehicle has started at a certain acceleration and alerting the driver of the acceleration state by an alarm.

Also at this time, when the start of the own vehicle is detected, the alarm is not necessary and is reset (see FIG. 4 (I
V)).

This prevents unnecessary warnings that are offensive to the driver.

A concrete flowchart of the control conceptual diagram of FIG. 4 described above is shown in FIG. 5 as a program flow chart of the control unit 6, and an embodiment of the present invention will be described below with reference to this flow chart.

First, when this program is started, under the system ON condition S1, it is unnecessary to generate an alarm and is stopped until one or more running states are detected after the engine is started (step S11) (step S11). S11, 12).

The system ON condition S1 is not essential to the present invention as described above and can be omitted.

Next, in the system setting condition S2, first set the timer to x
It is set to seconds (step S21), and it is determined whether or not the alarm requirement is satisfied (step S22).

The alarm requirement in this case is that the vehicle is stopped at a vehicle speed of 0 km / h, for example. Incidentally, various necessary conditions for this alarm can be considered depending on the setting (design) of the system as shown in FIG. 6, which will be explained after the explanation of FIG.

When an alarm is required, for example, when the vehicle speed is 0, the control unit 6 energizes the transceivers 10 and 20 to emit an ultrasonic pulse forward to detect the vehicle ahead (step S2).
3).

In this case, a fixed reference forward distance from the host vehicle is set, and the actual reflection time is the same as or shorter than the reflection time t (see FIG. 1B) of the ultrasonic pulse corresponding to this distance. The presence of a vehicle in front can be detected depending on whether the vehicle is ahead (step S24).

Then, when it is detected that there is a forward vehicle, it is determined whether or not the timer flag set as described above has reached x seconds (step S25), and the forward vehicle is present before reaching x seconds. When it disappears, when the alarm requirement S22 is not satisfied (when the host vehicle starts, etc.), the system setting condition S2 is reset and returns to the beginning, but when the presence of a vehicle ahead is continuously detected for x seconds. The judgment of the system setting condition S2 is completed and the process proceeds to the alarm output condition S3.

In this way, after confirming the presence of the front vehicle under the system setting conditions, first, in the alarm output condition S3, the inter-vehicle distance between the front vehicle and the own vehicle corresponding to the reflection time t of the ultrasonic pulse is calculated, and α is set to this distance. (This is a value for absorbing the variations of the ultrasonic transmitter / receiver 10 and the like) and set this as D1 (step S31).

Then, even in the alarm output condition S3, the timer for determination is set to y seconds (may be the same as x seconds), and then in step S33, the same vehicle detection as in step S23 is performed.
In step S33, it is determined whether or not a vehicle ahead is present with the distance D1 as a reference distance (step S34).

Then, while the preceding vehicle is within the inter-vehicle distance D1, step S3
Repeating steps 2 to 34, the measurement timer T is started when D1 is exceeded (step S35). The timer T is incremented by the clock of the control unit 6 separately from this program.

Then, in step S36, the same front vehicle detection as in steps S23 and S33 is performed, but in this step S36, it is determined whether or not a front vehicle exists with the inter-vehicle distance D2 larger than the distance D1 as a reference distance. Step S37).

If the vehicle ahead is within the inter-vehicle distance D2, step S3
In step 8, as in step S22, it is determined whether or not the alarm necessary condition is satisfied. If not satisfied, for example, when the host vehicle starts moving, the process returns to step S21, but when satisfied, the timer time T is a predetermined time. It is determined whether or not (step S39).

As a result, if the predetermined time is not reached, step
S36 to S39 are repeated, but when the predetermined time is reached, that is,
For example, when the preceding vehicle stops after reaching the distance D2 after exceeding the distance D1, the process returns to the first step S31 of the alarm output condition S3.

By the time the vehicle ahead within the predetermined time of the in this way exceeds the inter-vehicle distance D2, is the elapsed time acceleration G from the inter-vehicle distance D1 to over D2 (G = (D2-D1 ) / T 2) It is calculated based on the timer time T (step S40).

Then, it is again determined whether or not the alarm requirement is satisfied (step S41). If not satisfied, the reset state is entered and the process returns to step S21. If the condition is satisfied, the determination timer flag y seconds elapse. It is determined whether or not (step S42), and the alarm output device 7 is activated when y seconds have elapsed.
Is activated (step S4).

Here, the alarm output device 7 can issue an alarm in a form corresponding to the acceleration G found in step S40. For example, if the starting acceleration of the vehicle ahead is large, the digital value of the acceleration is received from the control unit 6. Converted to an analog value, this analog voltage shortens the alarm sounding cycle and prompts the driver's attention.

Incidentally, the timer is used in the system setting condition S2 and the alarm output condition S3 as described above, as a result of the forward vehicle repeatedly starting and stopping during that period, the distance to the forward vehicle becomes shorter or longer than the reference distance, or Since the own vehicle may start, it is unnecessary and troublesome to sound the alarm each time, and even if it changes, it does not immediately output an alarm and the vehicle ahead certainly starts. This is to confirm. Further, it is possible to eliminate an unnecessary alarm even when a person, a bicycle, or the like crosses the front of the own vehicle.

Even without using a timer like this, steps S23 and S24
And the reference distance for detecting the forward vehicle in steps S33, S34 and S36, S37 from the former (for example, 5 m) to the latter (for example, D1) as described above.
= 5 + 2m, D2 = 10m), the warning will be issued as long as the preceding vehicle is not separated by 10m or more in the alarm output condition S3 even if it is detected that the preceding vehicle is within 5m in the system setting condition S2. Since it is not output, it is equivalent to having a fixed timer.

FIG. 6 shows a modification of steps S22, S38 and S41 for judging the alarm requirement shown in FIG. 5, which will be described below.

FIG. 6A shows a vehicle speed sensor as a vehicle stop state detecting means.
The condition is satisfied because it is necessary to issue an alarm because the vehicle is stopped when the vehicle speed = 0 km / h.

In the same figure (B), the judgment is made by the output of the parking brake switch 12 as the vehicle stop state detecting means instead of the vehicle speed sensor 11. When the switch 12 is on, the own vehicle is in the vehicle stop state, so the alarm necessary condition is satisfied. To do.

In the figure (C), in addition to the vehicle speed sensor 11, the accelerator pedal switch 13 as the starting operation detecting means is also used, so that even if the vehicle speed is 0 (step S221), the driver does not have to press the accelerator pedal. Since it is usual to look ahead, when the accelerator pedal switch 13 is on, the alarm requirement is not satisfied. Incidentally, the step
As shown in S222 ′, instead of using the accelerator pedal, the vehicle speed =
Even if it is 0, when the clutch pedal is stepped on (clutch pedal switch: ON), the alarm necessary condition may not be established because it is linked to the starting operation.

The figure (D) shows that the output of the gear position sensor 14 as the starting operation detecting means is further added to the figure (C) to make a determination (step S223). For example, when the vehicle speed = 0, the accelerator pedal is depressed. However, if the gear position is neutral N and parking P, it means that the vehicle has not started.
Drivers often don't look ahead, so it is assumed that the alarm requirements are met.

(E) of the figure is for judging the alarm necessary condition by each output of the vehicle speed sensor 11, the parking brake switch 12, and the brake pedal switch 15, even if the parking brake is not applied at the vehicle speed = 0 (step S224: OF
F) Immediately, the state of the foot brake pedal is judged not to be the start operation state (step S225), and if this is on, it is determined that an alarm should be issued, and it is not. Occasionally, it is determined that the vehicle is in the starting operation state and the alarm necessary condition is not satisfied.

In the same figure (F), the gear position is determined instead of the brake switch in step S225 of the same figure (E) (step S223).
However, if the gear position is in the state where the neutral N is in the parking P state, it is not in the starting operation state and it is necessary to issue an alarm.

FIG. 7G is obtained by adding a brake switch determination step S225 and a parking brake switch determination step S226 to step S223 of FIG. 7D, in which the accelerator pedal is depressed and the gear position is set to the traveling gear. In position,
If the parking brake is applied even if the brake pedal is not depressed, the vehicle is not in the start operation state and the alarm requirements are satisfied.

It should be noted that the determination may be made based on the output of the clutch pedal switch instead of the gear position in the above embodiment.

[Effect of device]

As described above, in the present invention, when the inter-vehicle distance between the front vehicle and the own vehicle measured and calculated when the stopped state of the own vehicle is intermittently detected is within a predetermined predetermined value, the front vehicle is It is determined that the vehicle ahead of the vehicle has started when the vehicle is in the stopped state when the inter-vehicle distance reaches two distances larger than the predetermined value within a predetermined time. Since the two-stage determination is made so that an alarm corresponding to the acceleration during that time is issued, the alarm does not sound unless the preceding vehicle separates from the own vehicle for a certain distance or more, and unnecessary and troublesome warnings can be eliminated, and It is expected that the driver can immediately recognize not only the start-up but also the traffic condition of the road accompanying the start-up situation by the alarm sound, and it is possible to avoid the driver from using extra nerves.

Further, in the present invention, the same warning can be issued as if the forward vehicle has started only when the same determination result is obtained for a predetermined time continuously in the presence determination of the forward vehicle. When a bicycle or the like crosses, unnecessary and troublesome alarms can be eliminated within a certain determination time.

Further, even when the vehicle is stopped, when the start operation detecting means detects the start operation, the user should be paying attention to the front, so that it is possible not to sound an unnecessary alarm.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a vehicle movement detection device according to the present invention, FIG. 2 is a diagram for explaining a mounting state of the vehicle movement detection device according to the present invention on a vehicle, and FIG. FIG. 4 is a diagram schematically showing control conditions of the present invention, FIG. 4 is a diagram showing various control conditions of the present invention in a conceptual hard image, and FIG. 5 is a flowchart of a control program executed by the present invention. FIG. 6 and FIG. 6 are flow charts showing various embodiments of the alarm necessary conditions used in FIG. In the figure, 1a, 1b ... Target object, 10, 20 ... Ultrasonic transceiver, 6 ... Control unit, 7 ... Alarm output device, 11
… Vehicle speed sensor, 12… Parking brake switch, 13…
Accelerator pedal switch, 14 ... Gear position sensor, 15 ... Brake pedal switch. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

(57) [Scope of utility model registration request] 1. An ultrasonic transmitter-receiver attached to a front portion of a vehicle,
A means for detecting the stopped state of the own vehicle, and when the stopped state is detected, the inter-vehicle distance between the preceding vehicle and the own vehicle is measured and calculated from the input / output of the transceiver, and the inter-vehicle distance is within a predetermined value. To the front vehicle when a signal indicating that the front vehicle is within the predetermined value is generated, and thereafter, the inter-vehicle distance successively reaches two predetermined values larger than the predetermined value within the predetermined time. Control for generating a signal indicating the presence of the vehicle and generating a signal indicating that the preceding vehicle has started in the stopped state, calculating the starting acceleration during that period, and energizing the alarm output device corresponding to the acceleration. A vehicle movement detection device comprising: 2. An ultrasonic transmitter / receiver attached to the front of the vehicle,
A means for detecting the stopped state of the own vehicle, and when the stopped state is detected, the inter-vehicle distance between the preceding vehicle and the own vehicle is measured and calculated from the input / output of the transceiver, and the inter-vehicle distance is predetermined for a predetermined duration. A signal indicating that the preceding vehicle is within the predetermined value is generated when the vehicle is within the predetermined value, and thereafter, when the inter-vehicle distance reaches two predetermined values that are larger than the predetermined value for a predetermined continuous time. A signal indicating the presence of the preceding vehicle is generated, and when the vehicle is in the stopped state, a signal indicating that the preceding vehicle has started is generated, the starting acceleration during that period is calculated, and an alarm output device is provided corresponding to the acceleration. A vehicle movement detection device, comprising: 3. A starting operation detecting means is further included, and the control means does not require an alarm when the starting operation detecting means detects a starting operation even if the vehicle stopping state detecting means detects a stopping state. The vehicle movement detection device according to claim 1 or 2, wherein the vehicle movement detection device generates a signal indicating.