JPH1199892A - Object detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an object detecting device which is correctly actuated even at low speed. SOLUTION: A detecting device OJC detects an object by detecting treatment devices DET1, DET2, DET3, DET4 through the change in the input impedance formed between sensor electrodes and the object. A controller CNT to permit or prohibit the drive of the detecting treatment devices is provided, the information from a vehicle speed pulse and a signal of a brake switch BKs are received by the controller, and the controller outputs the control signal Sc for permission or prohibition of the detecting treatment devices based on the information on the vehicle speed and the signal on the brake operating condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detection device, and more particularly to control of a controller for controlling a detection processing device for detecting an object using a sensor electrode.

[0002]

2. Description of the Related Art Conventionally, an object detection device is practical at low speeds such as when entering a garage or parking. However, an object detection device using an impedance change for object detection (detection of an obstacle) (for example, Japanese Patent Application Laid-Open No. 58-115384). JP, JP-A-3-233390
No. 6,009,098, which uses an impedance change, utilizes an electrostatic capacitance, so that not only an obstacle in front of which a detection request is required, but also an unnecessary object such as unevenness on a road surface is detected.

In order to prevent this, when it is not desired to detect an obstacle, the driver operates a start switch to prohibit the operation of the object detection device. However, it is troublesome for the driver to perform the starting operation manually, and an apparatus for automatically controlling the starting operation has been proposed in Japanese Patent Application Laid-Open No. 3-237386. This device detects the running speed of the vehicle and stops the function of the object detection device when the speed of the vehicle becomes equal to or higher than a predetermined speed.

[0004]

However, as described in the above publication, stopping the operation of the object detecting device when the traveling speed becomes equal to or higher than a predetermined speed does not detect irregularities on the road surface, and the The object detection device can be operated only when the vehicle is traveling at a low speed, for example, during parking or the like. However, when the vehicle is running at a low speed, such as when entering a garage or parking, a vehicle speed signal (vehicle speed pulse) is output.
Since the object detection device is operated only by the low speed, the number of pulses is reduced at a low speed, and the operation cannot be performed accurately. In other words, if the object detection device is started only with the vehicle speed information, for example, it starts too close to the object and then contacts an obstacle, or starts too early to easily cause a malfunction due to disturbance. Becomes unstable, and accurate determination cannot be performed.

[0005] Therefore, the present invention has been made in view of the above problems, and has as its technical object to provide an object detection device that operates accurately even at low speed.

[0006]

A first technical measure taken to solve the above-mentioned problem is that an object detection is performed by a detection processing device by a change in an input impedance formed between a sensor electrode and an object. The vehicle obstacle detection device includes a controller for permitting or prohibiting driving of the detection processing device. The controller receives vehicle speed information and a signal of a vehicle brake operation state, and the controller receives the vehicle speed information and the vehicle speed information. A control signal of permission or prohibition is output to the detection processing device based on the signal of the brake operation state.

With the above arrangement, the detection processing device is controlled to be permitted or prohibited by the controller based on the vehicle speed information and the signal of the brake operation state. Thus, accurate detection of a nearby object can be performed. In this way, when driving the vehicle, the driver always performs a braking operation when approaching an object (obstacle). Therefore, the brake signal and the vehicle speed signal allow the driver to brake even if a vehicle speed pulse does not enter at a low speed. The state of the operation signal allows the controller to operate the detection processing device.

Further, a second technical means taken to solve the above-mentioned problem is a failure of a vehicle in which a detection processing device detects an object by a change in an input impedance formed between a sensor electrode and the object. The object detection device includes a plurality of detection processing devices, and a controller for permitting or prohibiting the drive of each of the detection processing devices. The controller receives vehicle speed information and a signal indicating a brake operation state of the vehicle. A permission or prohibition control signal is output to the detection processing device based on the vehicle speed information and the signal of the brake operation state.

With the above arrangement, the plurality of detection processing devices are generally controlled by the controller, and the controller uses the signal of the brake operation state even at low speed based on the vehicle speed information and the signal of the brake operation state. Thus, accurate detection of a nearby object can be performed. In this way, when driving the vehicle, the driver always performs a braking operation when approaching an object (obstacle),
By the brake signal and the vehicle speed signal, even if the vehicle speed pulse does not enter at low speed, depending on the state of the brake operation signal,
A plurality of detection processing devices can be operated by the controller.

In this case, if the signal of the vehicle speed information has hysteresis at a predetermined low speed, repetitive activation (hunting) of the detection processing device at the switching speed is prevented, and accurate object detection can be performed at a low speed. .

[0011]

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

FIG. 1 shows a system configuration diagram in one embodiment of the present invention. In this figure, an object detection device OJC has two sensor electrodes (hereinafter, referred to as electrodes) 10a and 10c.
And four detection processing devices (DET1 to DET4),
A detection controller (hereinafter, referred to as a controller) C that comprehensively controls the plurality of detection processing devices DET1 to DET4
It has NT. Here, four detection processing devices DE
Although T1 to DET4 are used, the number of the detection processing devices DET1 to DET4 is two in the right corner of the bumper of the vehicle (DET1, DET4).
ET2), and two sets (DET3, DET4) are provided at the left corner. Each of the detection processing devices has the same structure and the same function.

The detection processing devices DET1 to DET4 are provided with a control signal Sc as a command signal (permission / prohibition) from the controller CNT. The high level H of the control signal Sc indicates object detection (permission), that is, activation of the detection processing device, and the low level L indicates no object detection instruction (prohibition), that is, stop of the detection processing device.

The controller CNT is supplied with a vehicle speed pulse (rectangular wave) from the vehicle speed pulse generator SPs input to the engine fuel injection control device EFI and depresses a brake pedal (not shown). The brake switch BKs that closes according to the brake operation state when the brake operation is performed is connected to the controller CNT and is input. Further, the controller CNT is provided with a power supply circuit P which is supplied from a vehicle battery and supplies a stable power supply Vcc even when the battery voltage fluctuates. While the engine key switch is closed (on), a constant voltage Vcc is supplied to each part. give. Furthermore, a drive circuit Bd for driving a buzzer Bz provided on the vehicle side is also provided.

The vehicle speed pulse generated by the vehicle speed pulse generator SPs is a frequency / voltage (F / V) of the controller CNT.
The converter Fvc converts the frequency of the vehicle speed pulse into an analog voltage and supplies the analog voltage to comparators Cmp1 and Cmp2. The comparator Cmp1 determines that the analog voltage is
High level above Km / h (hereinafter referred to as H), 10
Low level when lower than Km / h (hereinafter referred to as L)
Is output to the set input S of the flip-flop Ff. When the analog voltage corresponds to the vehicle speed, the comparator Cmp2 outputs H when the analog voltage is equal to or lower than 7 km / h, and outputs L when the analog voltage is higher than 7 km / h.
f to the reset input R. Therefore, the flip-flop Ff is set when the signal at the set input terminal rises from L to H (when the vehicle speed increases and exceeds 10 km / h), the Q output Ssr of the flip-flop is set to H,
When the reset input terminal R changes from L to H (when the vehicle speed decreases and becomes 7 Km / h or less), the Q output Ssr is switched from H to L.

The output Ssr is input to the OR gate Org in a state where the signal level is inverted. The other input of the OR gate Org is connected to the brake switch BKs. Therefore, the output of the OR gate Org at point A outputs H when the brake switch BKs is turned on or the output of the flip-flop Q is L. At the point A, not only the switching speed of the vehicle speed of 7 km / h (at the time of decrease) or 10 km / h (at the time of the rise), but also the vehicle speed becomes H when the brake pedal is depressed even when the vehicle speed is increased, In this state, since an unnecessary change in impedance is detected, an AND gate Ang is added to its output. The output of the OR gate Org enters one input to the AND gate Ang, and the set input S of the flip-flop is input to the other input (H when the vehicle speed is 10 km / h or more).
When the vehicle speed is higher than 10 km / h, the output of the AND gate Ang, that is, the control signal Sc for starting the detection processing device is closed (inhibited state). That is, by adding the AND gate Ang to the vehicle speed determination signal Ssr, the vehicle speed becomes 10 km / km.
At h or more, activation of the detection processing device is prohibited, and when the brake switch BKs is closed, it is permitted. In this case, even if a vehicle speed pulse does not enter, the vehicle can be started by a signal from the brake operation.

FIG. 2B shows a control flowchart of the control signal Sc of the detection controller CNT. In FIG. 2B, in step S101, it is determined whether or not the signal is H based on a signal from the vehicle speed pulse. This vehicle speed determination signal S
sr increases the vehicle speed as described above, and the vehicle speed is 10 km /
When the vehicle speed becomes equal to or greater than h, the vehicle switches from L to H. When the vehicle speed decreases, the vehicle switches from H to L when the vehicle speed becomes 7 Km / h or less. As described above, the output signal is switched at a predetermined low speed (7 km / h and 10 km / h).

In step S101, the vehicle speed determination signal Ssr is set to L (10 km / h or less when the vehicle speed increases, or 7 when the vehicle speed decreases).
km / h or less), the vehicle speed determination signal Ss
When r is L (low speed of 10 km / h), step S102 is performed, but when the vehicle speed determination signal Ssr is H, the process proceeds to step S104. In step S104, it is determined whether the brake switch BKs is turned on (closed state) by stepping on the brake, and step S102 is performed when the brake is operated, but when the brake is not operated, step S105 is performed.

In step S102, it is determined whether or not the inverted signal of the set input S of the flip-flop is L (the vehicle speed is 10 km / h or less).
km / h or less), the control signal Sc is set to H (permitted) in step S103. On the other hand, when the S signal is L
If not (vehicle speed is 10 km / h or more), step S
At 105, the control signal Sc is set to L (inhibited state).

Looking at the timing chart of FIG.
When the ignition switch is turned on, the controller C
The power of NT is turned on. At this time, the vehicle speed pulse does not come in, and when the brake pedal is depressed, the brake switch BK
s is opened, and the detection processing devices DET1 to DET4 are activated (permitted).

When the engine is started, the brake pedal is normally depressed and the brake is applied, and then when the vehicle starts running, the brake is released and the speed is increased.
When the brake is released, the brake switch BKs is not closed, and the detection processing devices DET1 to DET4 are stopped (inhibited). At this time, there is no problem even if the detection processing devices DET1 to DET4 are not activated, because the vehicle starts running. Even if there is an obstacle, the driver can apply the brake immediately, so the detection processing device D
There is no problem even if ET1 to DET4 are stopped.

Next, when stopping or parking, the driver applies a brake to reduce the vehicle speed. At this time, the brake switch BKs is closed and the vehicle speed is 10 km / h.
In the following cases, the AND gate Ang opens, and the detection processing devices DET1 to DET4 are activated. For example, low speed (10
km / h or less) and no vehicle speed pulse
By using the brake signal as a start condition, the detection processing devices DET1 to DET4 can be started.

As described above, since the signal of the brake operation state (brake switch BKs) is used in accordance with the vehicle speed signal, the brake operation in a state where the low-speed vehicle speed pulse does not enter is detected and the signal is used. Therefore, accurate detection of an object can be performed even at a low speed. For example, in the case of a garage, the driver can reduce the vehicle speed and apply a brake in a low speed state, so that the driver can recognize a start request, and can activate the detection processing devices DET1 to DET4 when necessary in a stable state.

When the control signal Sc of the controller CNT is L
When the state is switched from (prohibited state) to H (permitted state), pre-processing of object detection (calibration of oscillation level) is performed. in this case,
When an abnormality is detected, the output signal a1 is set to L (abnormal). In response to this abnormal signal, the light emitting diode Le1 lights up,
The output of the inverter In1 becomes H and is supplied to the buzzer drive circuit Bd via the diode D3, and the buzzer Bz is energized to generate a warning sound. When no abnormality is detected, the output signal Sa1 is set to H to perform object detection, and when an object is detected, S1 is set to L. In response to this signal, the light emitting diode Le2 is turned on, the output of the inverter In2 becomes H, is given to the buzzer driver Bd via the diode D4, and the buzzer Bz is energized to generate a warning sound. When the object detection is changed from permission to prohibition, the output signal S1 is set to H (no object). As a result, the light emitting diode Le2 is turned off, the output of the inverter In2 becomes L, and the buzzer Bz
Stops. Similarly, the detection processing devices DET2 to DET
T4 also operates.

FIG. 3 shows a circuit configuration of the detection processing device DET1, and FIG. 4 shows a configuration of the resonance / coupling circuit 2 shown in FIG. The detection processing device DET1 is provided at the right corner of the front bumper of the vehicle, and has a sensor electrode 10a of about 40 to 50.
Detect obstacles in the area within cm.

The configuration of the detection processing device DET1 will be described. The oscillation circuit 3 of the detection processing device DET1
Connected to the resonance / coupling circuit 2 to generate a high-frequency AC voltage v1,
It is applied to the primary side (see FIG. 4). The secondary side of the induction coil L includes the sensor electrode 10a and the second electrode 10c of the electrode unit 10. A temperature compensating circuit 5 is connected to the resonance / coupling circuit 2, and is controlled by the temperature compensating circuit 5 so that the oscillation level in the resonance state is constant regardless of the temperature.

FIG. 5 shows the distribution of electric lines of force around the electrode unit. In this figure, an AC voltage v is applied between a first electrode 10a and a second electrode 10c that is grounded (grounded).
n is applied. The first electrode 10a and the second electrode 10c are parallel plates, and when the two electrodes are considered as one set of a capacitor, the capacitance between the first electrode 10a and the second electrode 10c is determined by the distance between the two. If d, the permittivity of vacuum is ε0, the relative permittivity is εr, and the areas facing each other are S, then Co1 = (ε0 · εr · S) / d. Assuming a virtual boundary LL at a distance from the first electrode 10a and letting the capacitance in the electric field radiated from the first electrode 10a up to the virtual boundary LL be Cs, the first electrode 10a
Impedance Zin1 between the first electrode 10a and the second electrode 10c between the first electrode 10a and the ground (the second electrode 10c grounded).
Impedance between the first electrode 10a and the virtual boundary LL [−1 / (jωCo1)].
(JωCs)], and is represented by Zin1 = −1 / [jω (Co1 + Cs)]. Here, when an object (obstacle) such as a person, a building, or a metal exists between the virtual boundary LL and the first electrode 10a, the capacitance Cs of the radiated electric field between the virtual boundary LL and the first electrode 10a is increased. Change. Thereby, the impedance Zi
n1 changes. The first electrode 10a and the second electrode 10c
The capacitance Co1 between them becomes constant because the second electrode 10c is grounded.

Returning to FIG. 3, the DC constant voltage Vcc supplied from the power supply circuit P of the controller CNT is applied to each element of the electric circuit. It is the CPU 1 that controls the detection processing device DET1. The CPU 1 first stabilizes the oscillation of the oscillation circuit 3. In order to stabilize the oscillation of the oscillation circuit 3, C
PU1 reads the oscillation level VL, which is a DC voltage signal representing the oscillation level of the AC voltage v1, from Io-1 of the I / O port. Next, a digital data control voltage Vm is calculated so that the resonance / coupling circuit 2 satisfies the oscillation condition of the oscillation circuit 3 according to the oscillation level VL. Then, the digital data control voltage Vm is D / A-converted from the IO-2 of the I / O port via the ladder resistor RA, and given to the resonance / coupling circuit 2.

The control voltage Vm is applied to the series capacitor Cz1 side of the bicap diode (variable capacitance diode) VD in the resonance / coupling circuit 2, and the capacitance of the varicap diode VD changes according to the voltage level of the control voltage Vm. The capacitance on the secondary side of the resonance / coupling circuit 2 changes, and the oscillation condition of the oscillation circuit 3 is satisfied, and the oscillation is stabilized.

When the oscillation of the oscillation circuit 3 is stable, when an obstacle approaches the electrode unit 10 (electrode 10a), the impedance Zin1 of the electrode unit 10 changes, and the resonance / coupling circuit is changed according to the impedance change. The capacitance on the secondary side of 2 changes. Oscillation circuit 3
The oscillation condition of the AC voltage v1 generated by the oscillation circuit 3 changes.

A detection / amplification circuit 4 is connected to the oscillation circuit 3, and detects and amplifies the AC voltage v1 to amplify the AC voltage v1.
1 is converted into an oscillation level VL, which is a DC voltage that increases or decreases in accordance with a change in the oscillation level of the I / O port 1 of the CPU 1.
Give to O-1. The CPU 1 compares the oscillation level VL with the threshold value, and according to the comparison result, determines whether the IO
On / off signal from -5, that is, indicating presence or absence of an obstacle 2
Outputs a value signal. An inverted signal of this binary signal is an output signal S1 representing an obstacle, and when the output signal S1 is L,
As a result, the inverter In2 (see FIG. 1) applies the ON voltage H to the buzzer drive circuit Bd, the buzzer drive circuit Bd is energized to the alarm buzzer Bz, and the alarm buzzer Bz sounds.

[0032]

According to the first aspect of the present invention, there is provided an obstacle detecting device for a vehicle in which a detection processing device detects an object based on a change in input impedance formed between a sensor electrode and an object. A controller for permitting or prohibiting the vehicle. The controller receives vehicle speed information and a signal indicating a brake operation state of the vehicle, and the controller controls the detection processing device based on the vehicle speed information and the signal indicating the brake operation state. By outputting the control signal of permission or prohibition, the detection processing device is controlled to permit or prohibit by the controller based on the vehicle speed information and the signal of the brake operation state, and the signal of the brake operation state even at low speed. By using together, it is possible to accurately detect a nearby object.

According to the second aspect of the present invention, there is provided a vehicle obstacle detecting apparatus for detecting an object by a detection processing apparatus based on a change in input impedance formed between a sensor electrode and an object. A controller for permitting or prohibiting the drive of each of the detection processing devices; vehicle speed information and a signal of a brake operation state of the vehicle are input to the controller; and the controller is configured to perform control based on the vehicle speed information and the signal of the brake operation state. By outputting a control signal of permission or prohibition to the detection processing device, the plurality of detection processing devices are controlled by the controller as a whole, and the controller controls the vehicle speed information and the brake operation state. Based on the signal, the signal of the brake operation state can be used at low speed to accurately detect nearby objects. It can be performed to detect. If you do this,
When driving a vehicle, the driver always applies a brake when approaching an object (obstacle), so the brake signal and the vehicle speed signal allow the driver to use the brake operation signal at low speeds, even if a vehicle speed pulse does not enter. A plurality of detection processing devices can be operated by the controller.

In this case, if the signal of the vehicle speed information has a hysteresis at a predetermined low speed, the repetitive activation of the detection processing device at the switching speed is prevented, and accurate object detection can be performed at a low speed.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an object detection device according to an embodiment of the present invention.

2A is a diagram illustrating an output state of a vehicle speed determination signal of a controller illustrated in FIG. 1, and FIG. 2B is a flowchart illustrating an object detection instruction output by the controller.

FIG. 3 is a circuit block diagram of the detection processing device shown in FIG.

4 is an electric circuit diagram of the resonance / coupling circuit shown in FIG.

FIG. 5 is a plan view showing a state of lines of electric force of the electrode unit 10 shown in FIG.

FIG. 6 is a timing chart showing a vehicle speed and a permission or prohibition state of the detection processing device.

[Explanation of symbols]

DET1, DET2, DET3, DET4 Detection processing device CNT controller SPs Vehicle speed pulse generator BKs Brake switch

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tsune Inawa 2-1-1 Asahi-cho, Kariya-shi, Aichi, Japan Aisin Seiki Co., Ltd.

Claims (3)

[Claims] 1. An obstacle detection device for a vehicle, which detects an object by a detection processing device based on a change in input impedance formed between a sensor electrode and an object, comprising: a controller for permitting or prohibiting driving of the detection processing device. The controller receives vehicle speed information and a signal indicating a brake operation state of the vehicle, and the controller controls the detection processing device based on the vehicle speed information and the signal indicating the brake operation state. An object detection device that outputs 2. An obstacle detection device for a vehicle, wherein a detection processing device detects an object based on a change in an input impedance formed between a sensor electrode and an object, comprising: a plurality of detection processing devices; A controller for permitting or prohibiting the driving of the vehicle. The controller receives vehicle speed information and a signal indicating a brake operation state of the vehicle, and the controller is configured to detect the detection processing device based on the vehicle speed information and the signal indicating the brake operation state. An object detection device, which outputs a control signal of permission or prohibition of the object. 3. The object detection device according to claim 1, wherein the signal of the vehicle speed information has a hysteresis at a predetermined low speed.