JP2006347433A - Inter-vehicle distance information processor and inter-vehicle distance controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inter-vehicle distance information processor and an inter-vehicle distance controller for improving reponsiveness by quickly recognizing an inter-vehicle distance even if the inter-vehicle distance sharply changes. <P>SOLUTION: This inter-vehicle distance information processor is provided with an inter-vehicle distance detection means 100 for detecting inter-vehicle distance information between an own vehicle and a preceding vehicle and a filtering means 106 for filtering the inter-vehicle distance information, and configured to process and output the inter-vehicle distance information. The inter-vehicle distance information processor is provided with a switching means 207 for, when the change rate of the inter-vehicle distance information detected by the inter-vehicle distance detection means 100 or the change rate of the filtered inter-vehicle distance information filtered by the the filtering means 106 is a predetermined value or larger, outputting the detected inter-vehicle distance information, and for, when the change rate of the inter-vehicle distance information detected by the inter-vehicle distance detection means 100 or the change rate of the filtered inter-vehicle distance information filtered by the filter means 106 is a predetermined value or smaller, outputting the filtered inter-vehicle distance information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is suitable for use in an auto cruise control device or the like for automatically driving a vehicle at a predetermined speed, and detects inter-vehicle distance information between the host vehicle and a preceding vehicle and processes inter-vehicle distance information. The present invention relates to a processing device and an inter-vehicle distance control device.

In recent years, a technology for controlling the traveling of a vehicle based on the inter-vehicle distance information between the own vehicle and an object ahead of the own vehicle (preceding vehicle) has been developed. For example, the vehicle is automatically determined at a set speed. 2. Description of the Related Art An auto cruise device that travels at a high speed has been put into practical use with an inter-vehicle distance control function that detects the inter-vehicle distance from a preceding vehicle and maintains this at a predetermined distance.
In such an auto cruise device with an inter-vehicle distance control function, the presence or absence of a preceding vehicle is detected, and when the preceding vehicle is not detected, constant speed control is performed to maintain the set vehicle speed at the set vehicle speed, and the preceding vehicle is detected. In such a case, an inter-vehicle distance control is performed in which the inter-vehicle distance between the host vehicle and the preceding vehicle is detected and the inter-vehicle distance is maintained at a predetermined distance based on the detected inter-vehicle distance information.

  In such inter-vehicle distance control, inter-vehicle distance information is detected by an inter-vehicle distance sensor such as a laser radar or a camera. The detected inter-vehicle distance information is output, for example, as a voltage value signal or the like and input to an ECU (electronic control unit) of the vehicle. Based on the inter-vehicle distance information, the ECU sets the target acceleration of the vehicle and the like. By controlling acceleration / deceleration, the inter-vehicle distance between the host vehicle and the preceding vehicle is maintained at the set inter-vehicle distance.

  At this time, the signal value of the inter-vehicle distance information (see the thin solid line in FIG. 7) input from the inter-vehicle distance sensor is greatly affected by noise and the like, and it is difficult to perform stable control. The inter-vehicle distance is recognized using a signal obtained by performing a filtering process on the inter-vehicle distance information signal input from the inter-vehicle distance sensor and smoothing and stabilizing the signal value (see a thick solid line in FIG. 7). The filtering process is performed at regular intervals (for example, 20 msec) by a commonly used low-pass filter (LPF).

The inter-vehicle distance sensor is not always limited to a specific object (preceding vehicle), but always detects inter-vehicle distance information for an object closest to the own vehicle in front of the own vehicle.
For example, when an interrupting vehicle appears between the host vehicle and a preceding vehicle traveling in front of the host vehicle, the inter-vehicle distance sensor detects the target object for detecting the inter-vehicle distance information from the time when the interrupting vehicle is detected. The signal value of the inter-vehicle distance information is output by switching to the interrupting vehicle.

As a result, the signal value of the inter-vehicle distance information output from the inter-vehicle distance sensor rapidly changes from the value of the inter-vehicle distance information for the preceding vehicle when there is no interrupting vehicle to the value of the inter-vehicle distance information for the interrupting vehicle. . Such a sudden change in the inter-vehicle distance also occurs when the preceding vehicle deviates from the own vehicle lane due to a lane change or a branch.
By the way, when the signal is filtered, the value (filtered signal value) calculated by the filter (LPF) is the current signal value (detected signal value) and the calculated value (filtered signal value) calculated one cycle before. Based on the above.

Accordingly, the signal value after filtering is cumulatively affected by the detection signal value in each previous period. Of course, this influence becomes larger as the latest detection signal value becomes, and becomes smaller as the previous filtered signal value.
For this reason, as shown in FIG. 7, even if the detection signal value changes, the post-filter signal value does not change immediately. The signal value has a smooth fluctuation characteristic.

  However, at the same time, the signal value after the filter is inevitably delayed with respect to the change in the detection signal value. In particular, even when there is an interruption to the own vehicle lane of another vehicle at the time T1, and the detected signal value changes abruptly because the interruption vehicle disappears from the own vehicle lane at the time T2, the signal value after filtering Does not change abruptly, a large difference occurs between the signal value before and after filtering, and a certain time difference (as shown in FIG. 7) until the signal value after filtering becomes close to the signal value before filtering. ΔT) occurs.

For this reason, when the inter-vehicle distance is suddenly narrowed due to an interruption or the like, the response of the signal value after filtering to the change in the signal value of the inter-vehicle distance sensor is delayed when the signal value of the inter-vehicle distance sensor is filtered. As a result, there is a problem that the ECU is delayed in recognizing the actual inter-vehicle distance, and thus the inter-vehicle distance control by the ECU is delayed.
The present invention has been devised in view of such problems, and can be suitably used for an auto cruise control device and the like, and can remove noise included in the detected inter-vehicle distance (information) and can also be used for inter-vehicle distance. An object of the present invention is to provide an inter-vehicle distance information processing device and an inter-vehicle distance control device that can quickly recognize the inter-vehicle distance even when the vehicle speed changes abruptly.

In order to achieve the above object, the inter-vehicle distance information processing device according to the present invention as claimed in claim 1 detects inter-vehicle distance information between the own vehicle and a preceding vehicle traveling in front of the own vehicle. If, comprising filter means for filtering the inter-vehicle distance information該車distance detecting means detects, and in the processing apparatus of the inter-vehicle distance information processing and outputting該車distance information,該車distance detecting means detects When the change rate of the inter-vehicle distance information or the change rate of the filtered inter-vehicle distance information filtered by the filter means is equal to or greater than a predetermined value, the inter-vehicle distance information detected by the inter-vehicle distance detection means is output, and the inter-vehicle distance detection If the change rate of the inter-vehicle distance information detected by the means or the change rate of the post-filter inter-vehicle distance information filtered by the filter means is less than a predetermined value, the post-filter inter-vehicle distance information It is characterized in that it comprises a switching means for outputting.

According to a second aspect of the present invention, there is provided the processing device for the inter-vehicle distance information according to the first aspect, wherein the filter means filters the inter-vehicle distance information at a preset calculation cycle, Filtered inter-vehicular distance information F (n) at n, inter-vehicle distance information L (n) at the computation cycle n, and filtered post-vehicle distance information F (n-1) at the computation cycle (n-1) before one computation cycle Is
F (n) = aF (n−1) + bL (n) (1)
However, a + b = 1, 0 <a, 0 <b
It is characterized by satisfying the relationship.

According to a third aspect of the present invention, there is provided the processing device for the inter-vehicle distance information according to the second aspect, wherein the rate of change of the inter-vehicle distance information is the inter-vehicle distance information obtained from the inter-vehicle distance detecting means in the calculation cycle n. It is detected on the basis of the difference between L (n) and the inter-vehicle distance information L (n-1) obtained from the inter-vehicle distance detection means in the arithmetic cycle (n-1) one arithmetic cycle before. Yes.
The inter-vehicle distance control device according to claim 4 is an inter-vehicle distance detecting unit that detects an inter-vehicle distance between an acceleration / deceleration unit that accelerates or decelerates the host vehicle and a preceding vehicle that travels ahead of the host vehicle. Filter means for filtering the inter-vehicle distance information detected by the inter-vehicle distance detection means, the rate of change of the inter-vehicle distance information detected by the inter-vehicle distance detection means, or the post-filter inter-vehicle distance information filtered by the filter means When the rate of change is equal to or greater than a predetermined value, the inter-vehicle distance information detected by the inter-vehicle distance detecting unit is output, and the rate of change of the inter-vehicle distance information detected by the inter-vehicle distance detecting unit or the filtered inter-vehicle distance filtered by the filter unit Switching means for outputting distance information after the filtered vehicle filtered by the filter means when the rate of change of the distance information is less than a predetermined value. It is characterized by controlling the the pressurized deceleration means based on the output value of said switching means.

  Therefore, according to the inter-vehicle distance information processing apparatus of the first aspect of the present invention, since the detected inter-vehicle distance information is normally filtered to suppress the influence of noise, stable control is performed. On the other hand, for example, when the inter-vehicle distance changes suddenly, such as when an intervening vehicle appears in the traveling lane of the host vehicle, the inter-vehicle distance suddenly decreases, the detected inter-vehicle distance information (detection signal value) Since the acceleration / deceleration control means outputs the inter-vehicle distance information (detection signal value) detected by the inter-vehicle distance detection means when the change rate or the change rate of the filtered post-filter inter-vehicle distance information is greater than or equal to a predetermined value, Even when the inter-vehicle distance changes rapidly due to the appearance of an interrupting vehicle, the inter-vehicle distance can be recognized with good responsiveness.

According to the inter-vehicle distance information processing apparatus of the second aspect of the present invention, in addition to the effect of the first aspect, the minute fluctuation (noise) included in the detection signal value can be surely removed. Therefore, it is possible to stably process the inter-vehicle distance information.
According to the inter-vehicle distance information processing apparatus of the third aspect of the present invention, in addition to the effect of the second aspect, the change rate of the detection signal value is the difference between the current value and the detection signal value before one calculation cycle. Can be detected quickly and reliably.

  According to the inter-vehicle distance control device of the present invention as set forth in claim 4, the own vehicle is accelerated / decelerated based on the inter-vehicle distance information with good response from which noise is removed. Stable control that is unlikely to cause hunting can be performed.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
1 to 4 are diagrams for explaining an inter-vehicle distance information processing device and an inter-vehicle distance control device according to a first embodiment as an embodiment of the present invention, and FIG. 1 is a block diagram showing the configuration thereof. FIG. 2, FIG. 2 is a circuit diagram schematically showing an arithmetic circuit relating to the filtering process, FIG. 3 is a flowchart for explaining the filtering process, and FIG. 4 is an inter-vehicle distance information (detection signal value) and a filtered signal value in the present embodiment. It is a graph which shows a time-dependent change.

  In this embodiment, the inter-vehicle distance information processing device and inter-vehicle distance control device of the present invention are applied to an auto cruise control device. In this auto cruise control device, when there is no preceding vehicle ahead of the host vehicle or when the distance between the host vehicle and the preceding vehicle is sufficiently wide (when the distance between the vehicles is a predetermined distance or more), the vehicle is automatically set at the set speed. A constant speed control mode in which the vehicle travels at a constant speed, and when the inter-vehicle distance is shorter than a predetermined distance, the inter-vehicle distance is controlled by accelerating / decelerating the traveling speed of the host vehicle so that the inter-vehicle distance is maintained at the predetermined distance. The inter-vehicle distance control mode is implemented. The functional part that implements the constant speed traveling mode of the auto cruise control device corresponds to the constant speed control device, and the functional part that implements the inter-vehicle distance control mode corresponds to the inter-vehicle distance control device of the present invention.

The predetermined distance in this case can be set to a constant value in the simplest case, but is set to a value corresponding to the traveling speed so that the predetermined distance increases (for example, increases in a quadratic function) as the vehicle speed increases. May be.
As shown in FIG. 1, an auto cruise control apparatus according to the present embodiment includes an ECU (electronic control unit) 105 including a memory (ROM, RAM), a CPU, and the like, an inter-vehicle distance detection means (inter-vehicle distance sensor) 100, a vehicle speed. A sensor 101, a brake switch 102, an accelerator opening sensor 103, and an operation switch 104 are provided, and a throttle actuator 108 and a brake actuator 109 are further provided.

The input side of the ECU 105 is connected to an inter-vehicle distance detecting means (an inter-vehicle distance sensor) 100, a vehicle speed sensor 101, a brake switch 102, an accelerator opening sensor 103, and an operation switch 104, and an output side of the ECU 105 is connected to a throttle actuator 108. And a brake actuator 109 is connected.
A vehicle speed sensor 101, a brake switch 102, and a throttle opening sensor 103 are sensors for detecting information on the traveling speed of the host vehicle, on / off of a brake pedal (not shown), and the opening of a throttle valve, respectively. The operation switch 104 is a switch for instructing the ECU 105 to start auto-cruise control. When the driver turns on the operation switch 104, the auto-cruise control at the traveling vehicle speed at that time is started. The operation switch 104 is also provided with a function that can increase or decrease the set vehicle speed during auto-cruising.

In addition, the auto-cruise control can be released by turning off the operation switch 104, but the auto-cruise control is also released by the brake operation detected from the signal of the brake switch 102.
The inter-vehicle distance sensor 100 is a sensor that detects, for example, the presence or absence of an object (preceding vehicle) ahead of the host vehicle and the inter-vehicle distance between the host vehicle and the preceding vehicle using a laser radar or the like. Here, the detected inter-vehicle distance information is a voltage value. A signal (detection signal value) is output. The inter-vehicle distance sensor 100 has a detection limit value Dlim (150 meters in this case). If there is no preceding vehicle or the inter-vehicle distance is greater than or equal to the detection limit value Dlim, the inter-vehicle distance sensor 100 detects the detection limit value Dlim. Is output as inter-vehicle distance information.

Further, the ECU 105 includes a filtered inter-vehicle distance acquisition unit 111 and an acceleration / deceleration control unit 107 as functional elements.
The detection signal (inter-vehicle distance information) input from the inter-vehicle distance sensor 100 to the ECU 105 is processed by the post-filter inter-vehicle distance acquisition means 111, and minute fluctuations (noise) included in the detection signal (inter-vehicle distance information) are removed. The signal value is converted into a stable signal value (filtered inter-vehicle distance information) with little unnecessary fluctuation. Then, based on this filtered inter-vehicle distance information, the inter-vehicle distance recognition unit 110 recognizes the presence or absence of the preceding vehicle amount and the inter-vehicle distance between the host vehicle and the preceding vehicle.

  When the post-filter inter-vehicle distance information processed by the post-filter inter-vehicle distance acquisition unit 111 is equal to or greater than a predetermined value D0, the ECU 105 determines that there is no preceding vehicle ahead of the host vehicle, or the host vehicle and the preceding vehicle. The above-described constant speed control mode is performed by determining that the following inter-vehicle distance is sufficient, and when the inter-vehicle distance is smaller than a predetermined value D0, the above-mentioned inter-vehicle distance control mode is performed.

The value of the predetermined value D0 is stored in the storage device of the ECU 105 as a map corresponding to the vehicle speed V, and the ECU 105 sets the value of the predetermined value D0 corresponding to the vehicle speed V of the host vehicle input from the vehicle speed sensor 101. .
That is, when the ECU 105 recognizes that the operation switch 104 is on and the filtered inter-vehicle distance information is equal to or greater than the predetermined value D0, the ECU 105 starts the constant speed mode control and sets the vehicle speed V input from the vehicle speed sensor 101 at that time. The vehicle speed V0 is stored in the ECU 105, and the acceleration / deceleration control means 107 of the ECU 105 controls the throttle actuator 108 and the brake actuator 109 on the basis of inputs from the vehicle speed sensor 101, the brake switch 102, and the throttle opening degree sensor 103 to control the host vehicle. Is controlled so that the host vehicle travels at the set vehicle speed V0.

  Further, when the ECU 105 recognizes that the operation switch is 104 ON and the inter-filter inter-vehicle distance is smaller than the predetermined value D0, the inter-vehicle distance mode control is started, and the acceleration / deceleration control means 107 of the ECU 105 is operated by the inter-vehicle distance recognition unit 110. Based on the recognized post-filter inter-vehicle distance information, the input from the vehicle speed sensor 101, the brake switch 102, and the throttle opening sensor 103, the throttle actuator 108 and the brake actuator 109 as acceleration / deceleration means are controlled to accelerate / decelerate the own vehicle. Thus, the inter-vehicle distance is controlled so that the inter-vehicle distance becomes a predetermined value D0.

Next, with reference to FIGS. 2, 3, and 4, processing for calculating the filtered inter-vehicle distance information (also referred to as a post-filter signal value) in the post-filter inter-vehicle distance acquisition unit 111 including the LPF 106 will be described. The inter-vehicle distance information processing apparatus according to the present invention is configured by the filtered inter-vehicle distance acquisition unit 111 and the inter-vehicle distance sensor 100.
As shown in FIG. 2, the filtered inter-vehicle distance acquisition unit 111 includes a signal recognition unit 205, an LPF 106, an inter-vehicle distance change determination unit 206 as a switching unit, and a switch 207. The LPF 106 includes the first amplifier 201, the first amplifier 201, and the switch 207. 2 amplifier 202, delay element 203 and adder circuit 204. The first amplifier 201, the second amplifier 202, the delay element 203, and the adder circuit 204, which are each of these elements, do not need to be provided as a single member, but may be provided as, for example, a functional element of a computer.

The signal recognition unit 205 is connected to the inter-vehicle distance sensor 100 so that a detection signal of the inter-vehicle distance sensor 100 is input. The signal recognition unit 205 recognizes the value of the detection signal input from the inter-vehicle distance sensor 100 every one calculation cycle (here, 20 milliseconds), and uses the recognized value as the detection signal value L (n) for one calculation cycle. It is designed to output every time.
The functional elements included in the LPF 106 will be further described. The first amplifier 201 is interposed between the delay element 203 and the adder circuit 204, and the second amplifier 202 is interposed between the signal recognition unit 205 and the adder circuit 204. The first amplifier and the second amplifier output values obtained by multiplying the input signal values by set filter coefficients a and b (where a + b = 1, a> 0, b> 0), respectively. It has become. The filter coefficients a and b are values set in advance so that a minute change (noise) of the detection signal value L (n) can be sufficiently removed. In general, the larger the filter coefficient a (the smaller the filter coefficient b) is, the larger noise can be removed. However, the response delay with respect to the change in the detection signal value L (n) increases, so the values of the filter coefficients a and b reliably At the same time, the response delay to the change in the detection signal value L (n) is set so as not to become so large.

  Note that the response delay here (that is, the response delay to be considered in determining the filter coefficients a and b) does not include a response delay with respect to a sudden change in the inter-vehicle distance due to an interruption of the preceding vehicle or a lane change. This is because the response speed to these sudden changes in the inter-vehicle distance is ensured by the inter-vehicle distance change determination unit 206 and the switch 207. Therefore, in the present invention, it is not necessary to consider interruption and lane change when determining the LPF coefficient, so that a more appropriate coefficient can be determined.

The adder circuit 204 is configured to receive signal values from the first amplifier 201 and the second amplifier 202, and adds and outputs the input signal value values.
The delay element 203 is interposed between the switch 207 and the first amplifier 201, and delays the signal value (ie, the filtered signal value) input via the switch 207 by one calculation cycle (20 milliseconds). It is designed to output.

  Therefore, the inter-vehicle distance information (detection signal) input from the inter-vehicle distance sensor 100 to the filtered inter-vehicle distance acquisition unit 111 is first input to the signal recognition unit 205 and the signal value is recognized every one calculation cycle (20 milliseconds). Is done. The signal recognition unit 205 sends the recognized signal value as the detection signal value L (n) to the second amplifier 202, the switch 207, and the inter-vehicle distance change determination unit 206.

Here, a path that is input from the signal recognition unit 205 to the switch 207 via the second amplifier 202 and the addition circuit 204, that is, a path that passes through the LPF 106 is referred to as a route 1, and the signal recognition unit 205 to the switch 207 without passing through the LPF 106. The route directly inputted to is called route 2.
In route 1, the second amplifier 202 sends a signal value bL (n) obtained by multiplying the detection signal value L (n) input from the signal recognition unit 205 by the filter coefficient b to the adder circuit 204.

On the other hand, the first amplifier 201 receives the filtered signal value F (n−1) one computation cycle before from the delay element 203, and the first amplifier inputs the filtered signal value F (n−1) one computation cycle before. The signal value aF (n−1) obtained by multiplying −1) by the filter coefficient a is sent to the adder circuit 204.
The adder circuit 204 adds the signal value aF (n−1) input from the first amplifier 201 and the signal value bL (n) input from the second amplifier 202, and adds the signal value aF (n− 1) Output + bL (n).

That is, considering the route 1 as a whole, the input detection signal value L (n) is passed through the LPF 106, that is,
F (n) = aF (n−1) + bL (n) (1)
As output.
In the route 2, the detection signal value L (n) does not pass through the LPF 106, that is, the value as it is,
F (n) = L (n) (2)
As output.

  One end (output end) of the switch 207 is fixed, and the other end (input end) is arranged to switch connection / disconnection between the Y side terminal and the N side terminal by energizing a solenoid (not shown). . The fixed terminal (output terminal) is connected to the acceleration / deceleration control means 107 and the delay element 203 of the LPF 106, and outputs a filtered signal value F (n) as an output signal. On the other hand, the Y-side terminal as the input terminal is connected to the signal recognition unit 205 (that is, route 2), and the N-side terminal as the input terminal is also connected to the addition circuit 204 (that is, route 1) of the LPF 106, respectively. ing.

The detection signal value L (n) is input from the signal recognition unit 205 to the inter-vehicle distance change determination unit 206, and the input detection signal value L (n) is stored in a storage device inside the inter-vehicle distance change determination unit 206. It has become.
Further, the inter-vehicle distance change determination unit 206 calculates a difference between the detection signal value L (n) of the current calculation cycle and the stored detection signal value L (n−1) of the previous calculation cycle, and the calculated value Are compared with a predetermined value S set in advance. When the difference between the detection signal value L (n) and the detection signal value L (n−1) one calculation cycle before is smaller than the predetermined value S (that is, when the change rate of the detection signal is small), The switch 207 is connected to the terminal on the N side assuming that there is no sudden change in the inter-vehicle distance, and when the above difference is equal to or greater than the predetermined value S (that is, when the change rate of the detection signal is large), the inter-vehicle distance is changed suddenly. The switch 207 is controlled so as to connect 207 to the terminal on the Y side. Since the fluctuation of the signal value due to the noise included in the detection signal value L (n) is sufficiently small with respect to the fluctuation of the signal value due to the sudden change of the inter-vehicle distance, the predetermined value S is changed to the sudden change of the signal value fluctuation amount due to the noise and the inter-vehicle distance. By setting the intermediate value between the fluctuation amount of the signal value due to the noise, it is possible to prevent erroneous determination of noise included in the detection signal value L (n) and a sudden change in the inter-vehicle distance.

Therefore, when the switch 207 is connected to the terminal on the N side (that is, when | L (n) −L (n−1) | ≦ predetermined value S), the filtered signal value from the LPF 106 (Route 1). F (n) is output and input to the acceleration / deceleration control means 107 and the delay element 203 of the LPF 106.
Further, when the switch 207 is connected to the Y-side terminal (that is, when | L (n) −L (n−1) |> predetermined value S), the inter-filter inter-vehicle distance from the LPS 106 (Route 2) F (n) is output and input to the acceleration / deceleration control means 107 and the delay element 203 of the LPF 106.

  Since the inter-vehicle distance information processing apparatus and inter-vehicle distance control apparatus according to the first embodiment of the present invention are configured in this manner, as shown in FIG. When the difference between the detection signal value L (n) and the detection signal value L (n-1) one calculation cycle before is calculated and the calculated difference is smaller than the predetermined value S, the inter-vehicle distance detected by the inter-vehicle distance sensor 100 is detected. It is determined that the change rate of the distance information (detection signal) is small, and the process proceeds to step S02.

In step S01, if the difference between the current detection signal value L (n) and the detection signal value L (n) one calculation cycle before is equal to or greater than the predetermined value S, the inter-vehicle distance detected by the inter-vehicle distance sensor 100 is detected. It is determined that the rate of change of information (detection signal) is large, and the process proceeds to step S03.
In step S02, the inter-vehicle distance change determination unit 206 connects the switch 207 to the N-side terminal, and in the route 1 of the post-filter inter-vehicle distance acquisition unit 111, the current detection signal value L (n) and one calculation cycle before Based on the filtered signal value F (n−1), the filtered signal value F (n) obtained by performing the calculation (referred to as filter calculation) to F (n) = aF (n−1) + bL (n) is obtained. Output from the LPF 106 via the switch 207. At this time, a + b = 1, a> 0, b> 0.

In step S03, the inter-vehicle distance change determination unit 206 connects the switch 207 to the terminal on the Y side, and the detection signal value L (n) recognized by the signal recognition unit 205 is not filtered from the LPF 106. It is output via 207.
Therefore, in normal times when there is no sudden change in the inter-vehicle distance, a filter operation is performed on the detection signal output from the inter-vehicle distance sensor 100, and the detection signal value L (n) and the post-filter signal value F (n−1) one calculation cycle before ) At a predetermined ratio, the detection signal that slightly changes is flattened to obtain a stable filtered signal value F (n). Therefore, the acceleration / deceleration control means 107 can perform stable control.

  Further, as shown in FIG. 4, the inter-vehicle distance is suddenly shortened due to the appearance of an interrupted vehicle at the time T1, or the inter-vehicle distance is suddenly increased due to the absence of the interrupted vehicle at the time T2. In the calculation cycle in which the sudden change in the inter-vehicle distance occurs, the detection signal value L (n) is used as the filtered signal value F (n) as it is, so that the acceleration / deceleration control means 107 is not delayed from the sudden change in the inter-vehicle distance. The distance can be controlled.

  Further, in this case, since the detection signal value L (n) is set as the filtered signal value F (n) as it is, when the filter calculation is performed in the subsequent calculation cycle, the filtered signal value before the sudden change in the inter-vehicle distance is obtained. Since it is not affected, the calculated filtered signal value F (n) is close to the detected signal value L (n) after the sudden change in the inter-vehicle distance, and a stable signal value is obtained while removing unnecessary noise. The acceleration / deceleration control means 107 can be input, and the acceleration / deceleration control means 107 can perform stable inter-vehicle distance control without being delayed with respect to a sudden change in the inter-vehicle distance.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIGS. 5 and 6 are for explaining the inter-vehicle distance information processing device and inter-vehicle distance control device according to the second embodiment as one embodiment of the present invention. FIG. FIG. 6 is a flowchart showing the control in the filter means.

In the present embodiment, as in the first embodiment described above, the inter-vehicle distance information processing device and inter-vehicle distance control device of the present invention are applied to an auto-cruise control device, and most of the configuration is shown in FIG. Since it is the same as that of the first embodiment, only the parts different from those of the first embodiment will be described here.
In addition, what is corresponded to 1st Embodiment is demonstrated using a same sign.

In the present embodiment, as shown in FIG. 5, the configuration of the after-filter inter-vehicle distance acquisition unit 251 is different from that of the first embodiment.
In this embodiment, the configuration of the LPF 106 is the same as that of the first embodiment, and includes the first amplifier 201, the second amplifier 202, the delay element 203, and the addition circuit 204, and is input from the inter-vehicle distance sensor 100. The detected signal is input to the signal recognizing unit 205, and the signal recognizing unit 205 outputs the detection signal value L (n) before the filter calculation every predetermined calculation cycle.

Then, in route 1 that is a route passing through the LPF 106, a filter operation F (n) = aF (n−1) + bL (n) (1) is applied to the detection signal input from the inter-vehicle distance sensor 100.
To output the filtered signal value F (n). In route 2, which does not pass through the LPF 106,
F (n) = L (n) (2)
The filtered signal value F (n) is output.

The inter-vehicle distance change determination unit 250 receives the filtered signal value F (n) in the route 1 of the LPF 106 from the adder circuit 204 of the LPF 106, and is filtered by one calculation cycle before the delay element 203 of the LPF 106. A signal value F (n-1) is input.
The inter-vehicle distance change determination unit 250 calculates and calculates the difference between the input filtered signal value F (n) in the calculation cycle n and the filtered signal value F (n−1) one calculation cycle before. The magnitude relationship between the value and the predetermined value S ′ set in advance is compared, and the difference between the filtered signal value F (n) and the filtered signal value F (n−1) one calculation cycle before is greater than the predetermined value S ′. Is also small (that is, when the change rate of the detection signal is small), the switch 207 is connected to the terminal on the N side on the assumption that there is no sudden change in the inter-vehicle distance, and the above difference is equal to or greater than the predetermined value S (that is, When the change rate of the detection signal is large), the switch 207 is controlled so that the switch 207 is connected to the terminal on the Y side, assuming that the inter-vehicle distance has suddenly changed. The predetermined value S ′ in the present embodiment is a value set in advance so that a sudden change in the inter-vehicle distance can be determined, and is preferably set to a value smaller than the predetermined value S in the first embodiment.

  As a result, when there is no sudden change in the inter-vehicle distance, route 1 is selected by the switch 207, and the filtered signal value F (n) filtered by the LPF 106 is input to the delay element 203 and the acceleration / deceleration control means 107. When a sudden change in the inter-vehicle distance occurs, the route 2 is selected by the switch 207, and the detection signal value L (n) from the signal recognition unit 205 without the LPF 106 is used as the filtered signal value F (n). The signal is input to the acceleration / deceleration control means 107.

That is, in this embodiment, the difference between the filtered signal value F (n) and the filtered signal value F (n−1) one calculation cycle before the change rate of the inter-vehicle distance information detected by the inter-vehicle distance detecting means | F Detection is performed by comparing (n) −F (n−1) | with a predetermined value S ′.
Since the inter-vehicle distance information processing apparatus and inter-vehicle distance control apparatus according to the second embodiment of the present invention are configured in this manner, the inter-vehicle distance change determination unit 250 of the LPF 106 is shown in FIG. The difference between the post-filter signal value F (n) input from the adder circuit 204 and the filter operation and the post-filter signal value F (n−1) one operation period input from the delay element 203 of the LPF 106 is calculated. If the calculated difference is smaller than the predetermined value S ′, it is determined that the rate of change of the inter-vehicle distance information (detection signal) detected by the inter-vehicle distance sensor 100 is small, and the process proceeds to step S12.

In step S11, if the difference between the filtered signal value F (n) in the current computation cycle and the filtered signal value F (n-1) in the previous computation cycle is equal to or greater than a predetermined value S ′, the inter-vehicle distance It is determined that the rate of change of the inter-vehicle distance information (detection signal) detected by the sensor 100 is large, and the process proceeds to step S13.
In step S12, the inter-vehicle distance change determination unit 250 selects the route 1 by connecting the switch 207 to the terminal on the N side, and detects the detection signal value L (n) of the current calculation cycle and the filter after one calculation cycle. A value obtained by performing the filter operation based on the signal value F (n−1) is output through the switch 207 as the filtered signal value F (n). Also in this case, a + b = 1, a> 0, b> 0.

In step S13, the inter-vehicle distance change determination unit 250 selects the route 2 by connecting the switch 207 to the terminal on the Y side, and the detection signal value recognized by the signal recognition unit 205 without being filtered by the LPF 106. L (n) is output via the switch 207.
Therefore, in the present embodiment, the detection signal value L (n) is compared by comparing the difference between the filtered value and the filtered signal value F (n−1) before one calculation period with the predetermined value S ′. ) Can be determined, and the same effect as in the first embodiment can be obtained.

Further, the inter-vehicle distance change determination unit 250 calculates and compares the two currently input signal values [that is, the filtered signal value F (n) and the filtered signal value F (n−1) one calculation cycle before]. Therefore, there is an advantage that it is not necessary to memorize the value before one calculation cycle, and the CPU or the like is not burdened.
[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

For example, depending on the inter-vehicle distance sensor, when the inter-vehicle distance is long, the amplitude of noise included in the inter-vehicle distance detection signal may increase due to a decrease in detection accuracy of the sensor. At this time, the detection signal value L (n ) And a variation in the detection signal value L (n) due to a sudden change in the inter-vehicle distance may be erroneously determined.
In such a case, the predetermined value S or S ′ in the above-described embodiment may be set to a different value depending on whether the detection signal value L (n) of the inter-vehicle distance is large or small. At this time, naturally, when the detection signal value L (n) is large, the predetermined value S or S ′ is set large, and when the detection signal value L (n) is small, the predetermined value S or S ′ is set small. To do. Further, the value of the predetermined value S or S ′ may be set in two or more stages corresponding to the magnitude of the detection signal value L (n) without being limited to two stages.

Thereby, even when the inter-vehicle distance is long and the amplitude of the noise included in the detection signal of the inter-vehicle distance sensor becomes large, the fluctuation of the detection signal value due to the noise is not confused with the sudden change of the inter-vehicle distance. Further, when the inter-vehicle distance is long, the fluctuation amount of the inter-vehicle distance due to an interrupting vehicle or the like is generally large, so that the sudden change of the inter-vehicle distance can be accurately determined when the inter-vehicle distance changes suddenly.
In addition, even when the vehicle speed of the host vehicle is high, it is conceivable that the amplitude of noise included in the inter-vehicle distance detection signal increases due to sensor vibration or the like. Accordingly, the values of the filter coefficients a and b in the above-described embodiment are not limited to constant values. For example, when the detection signal value L (n) (inter-vehicle distance) is large, the filter coefficient a is increased (the filter coefficient b is increased). When the detection signal value L (n) is small, the filter coefficient a may be set small (the filter coefficient b is large). In this way, even when the inter-vehicle distance is large and the amplitude of the noise of the inter-vehicle distance detection signal is large, the noise can be surely removed. Processing can be performed.

  Further, in the above-described embodiment, the rate of change of the inter-vehicle distance is determined by using the detection signal value L (n) and the detection signal value L (n−1) before one calculation cycle or the filtered signal value F (n) and one calculation cycle. Although the determination is made by comparison with the previous filtered signal value F (n-1), in order to more reliably determine the sudden change in the inter-vehicle distance, the current signal values L (n), F (n) and t The determination may be made by comparing the signal values L (nt) and F (nt) (where t is an integer of 2 or more) before the cycle. In this case, the larger the value of t, the more reliable the determination can be. However, since the responsiveness to changes in the inter-vehicle distance deteriorates, it is desirable to set the value of t within a range that does not impair the responsiveness (for example, t = 2).

  Further, it is needless to say that the time of the calculation cycle is not limited to that of the above-described embodiment (20 milliseconds) and can be changed as appropriate. Further, the inter-vehicle distance information processing device according to the present invention may be used for an inter-vehicle distance alarm device or the like.

It is a block diagram which shows the structure of the auto-cruise control apparatus to which the processing apparatus of the distance information between vehicles based on 1st Embodiment of this invention is applied. It is a circuit diagram showing typically the arithmetic circuit concerning filter processing in the processing device of the distance information between vehicles concerning a 1st embodiment of the present invention. It is a flowchart explaining the filter process based on 1st Embodiment of this invention. It is for demonstrating the processing apparatus of the inter-vehicle distance information based on 1st Embodiment of this invention, Comprising: An example of a time-dependent change of the detected inter-vehicle distance information (detection signal value) and the processed inter-vehicle distance information signal value It is a graph to show. It is a circuit diagram which shows typically the arithmetic circuit concerning the filter process in the inter-vehicle distance control apparatus based on 2nd Embodiment of this invention. It is a flowchart explaining the filter process based on 2nd Embodiment of this invention. It is a graph which shows an example of the time-dependent change of the signal value before a filter regarding the inter-vehicle distance information used for the conventional inter-vehicle distance control apparatus, and the signal value after a filter.

Explanation of symbols

100 Inter-vehicle distance detection means (inter-vehicle distance sensor)
101 Vehicle speed sensor 102 Brake switch 103 Throttle opening sensor 104 Actuation switch 105 ECU (electronic control unit)
106 LPF (filter means)
107 Acceleration / deceleration control means 108 Throttle actuator 109 Brake actuator 110 Inter-vehicle distance recognition unit 111, 251 Filtered inter-vehicle distance acquisition means 201 First amplifier 202 Second amplifier 203 Delay element 204 Adder circuit 205 Signal recognition unit 206, 250 Inter-vehicle distance change determination Part (switching means)
207 switch (switching means)

Claims (4)

Inter-vehicle distance detection means for detecting inter-vehicle distance information between the host vehicle and a preceding vehicle traveling in front of the host vehicle;
In the processing apparatus of the inter-vehicle distance information該車distance detecting means and a filter means for filtering the inter-vehicle distance information detected, processing and outputting該車distance information,
When the change rate of the inter-vehicle distance information detected by the inter-vehicle distance detection means or the change rate of the filtered inter-vehicle distance information filtered by the filter means is a predetermined value or more, the inter-vehicle distance information detected by the inter-vehicle distance detection means When the change rate of the inter-vehicle distance information detected by the inter-vehicle distance detection means or the change rate of the post-filter inter-vehicle distance information filtered by the filter means is less than a predetermined value, the post-filter inter-vehicle distance information is output. An inter-vehicle distance information processing apparatus comprising switching means. The filter means filters the inter-vehicle distance information at a preset calculation cycle,
Filtered inter-vehicle distance information F (n) in the calculation cycle n, inter-vehicle distance information L (n) in the calculation cycle n, and filtered post-vehicle distance information F (n−) in the calculation cycle (n−1) before one calculation cycle. 1) is
F (n) = aF (n−1) + bL (n) (1)
However, a + b = 1, 0 <a, 0 <b
The inter-vehicle distance information processing device according to claim 1, wherein the relationship is satisfied. The rate of change of the inter-vehicle distance information is calculated based on the inter-vehicle distance information L (n) obtained from the inter-vehicle distance detection unit at the calculation cycle n and the inter-vehicle distance detection unit at the calculation cycle (n−1) one calculation cycle before. The inter-vehicle distance information processing device according to claim 2, wherein the inter-vehicle distance information processing device is detected based on a difference from the inter-vehicle distance information L (n-1) obtained from the above. Acceleration / deceleration means for accelerating or decelerating the vehicle;
An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the host vehicle and a preceding vehicle traveling in front of the host vehicle;
Filter means for filtering the inter-vehicle distance information detected by the inter-vehicle distance detection means;
When the change rate of the inter-vehicle distance information detected by the inter-vehicle distance detection means or the change rate of the filtered inter-vehicle distance information filtered by the filter means is a predetermined value or more, the inter-vehicle distance information detected by the inter-vehicle distance detection means A filter that is output by the filter means when the change rate of the inter-vehicle distance information detected by the inter-vehicle distance detection means or the change rate of the filtered inter-vehicle distance information filtered by the filter means is less than a predetermined value. Switching means for outputting rear vehicle distance information,
An inter-vehicle distance control device that controls the acceleration / deceleration means based on an output value of the switching means.

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