JP2004086287A - Vehicle relative speed measurement device and vehicle control device - Google Patents

Abstract

An object of the present invention is to prevent an erroneous relative speed from being output due to detecting a distance to a side surface of an interrupting vehicle.
A laser radar measures a distance from a host vehicle to a preceding vehicle, calculates an instantaneous relative speed between the host vehicle and the preceding vehicle based on the measured inter-vehicle distance, and based on the calculated instantaneous relative speed. Thus, the relative speed between the own vehicle and the preceding vehicle is calculated. When a vehicle that interrupts between the host vehicle and the preceding vehicle is detected, the relative speed is not calculated if the amount of change in the instantaneous relative speed is larger than a predetermined value.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for measuring a relative speed between a host vehicle and a preceding vehicle, and an apparatus for controlling a vehicle using at least the relative speed.
[0002]
[Prior art]
2. Description of the Related Art An inter-vehicle distance control device including an inter-vehicle distance radar that emits a laser beam in front of a vehicle and measures the inter-vehicle distance between a host vehicle and a preceding vehicle based on reflected light reflected from an object is well known. This inter-vehicle distance control device calculates the relative speed between the host vehicle and the preceding vehicle from the inter-vehicle distance measured by the inter-vehicle distance radar, and keeps the inter-vehicle distance constant based on the inter-vehicle distance and the relative speed with the preceding vehicle. Controls throttle opening and brake fluid pressure.
[0003]
In such an inter-vehicle distance control device, when an interrupting vehicle enters from an adjacent lane between the host vehicle and the preceding vehicle, the distance from the host vehicle to the side of the interrupting vehicle is measured, and then the rear side of the interrupting vehicle is measured. The distance to may be measured. In such a case, even if the relative speed between the interrupting vehicle and the own vehicle is the same, the relative speed calculated based on the inter-vehicle distance changes, so that the own vehicle is controlled to decelerate, and the driver feels a sense of discomfort. There was something.
[0004]
In order to solve such a problem, for example, in the vehicle traveling control device described in Japanese Patent Application Laid-Open No. 2001-1790, the side detected by the following method is the side of the vehicle or the rear of the vehicle. Have identified. That is, the detection points detected by the scanning radar are grouped to detect the length of the detection object, and when the detected length is equal to or longer than a predetermined length, the side of the vehicle is detected. Deciding.
[0005]
[Problems to be solved by the invention]
However, the method used in the above-described vehicle travel control device has a problem that a high-resolution radar must be used.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle relative speed measuring device that prevents an erroneous relative speed caused by detecting a distance to a side surface of an interrupting vehicle from being output without using a high-resolution expensive radar device. And a vehicle control device.
[0007]
[Means for Solving the Problems]
(1) A relative speed measuring device for a vehicle according to the present invention comprises: an inter-vehicle distance measuring means for measuring a distance from the own vehicle to a preceding vehicle; and an instantaneous relative speed between the own vehicle and the preceding vehicle based on the measured inter-vehicle distance. An instantaneous relative speed calculation means for calculating, an instantaneous relative speed calculation means for calculating an instantaneous relative speed between the own vehicle and the preceding vehicle, and an instantaneous relative speed for calculating a change amount of the instantaneous relative speed calculated by the instantaneous relative speed calculation means Change amount calculating means, relative speed calculating means for calculating a relative speed between the own vehicle and the preceding vehicle based on the instantaneous relative speed, and interrupted vehicle detection for detecting a vehicle interrupting between the own vehicle and the preceding vehicle The relative speed calculation means does not calculate the relative speed if the amount of change in the instantaneous relative speed after the interrupted vehicle is detected by the interrupting vehicle detection means is greater than a predetermined value. To achieve the purpose.
(2) A relative speed measuring device for a vehicle according to the present invention comprises a signal transmitting means for transmitting a signal forward of the vehicle, and an inter-vehicle distance for measuring a distance from the own vehicle to a preceding vehicle based on the signal transmitted from the signal transmitting means. Measuring means, reflected signal intensity variation detecting means for detecting the intensity variation of the reflected signal of the signal transmitted by the signal transmitting means, and the instantaneous relative speed between the own vehicle and the preceding vehicle based on the measured inter-vehicle distance. An instantaneous relative speed calculating means for calculating, a relative speed calculating means for calculating a relative speed between the own vehicle and the preceding vehicle based on the instantaneous relative speed, and a splitting device for detecting a vehicle interrupting between the own vehicle and the preceding vehicle. And a relative speed calculating unit that does not calculate the relative speed if the amount of change in the reflected signal intensity after the interrupted vehicle is detected by the interrupting vehicle detecting unit is greater than a predetermined value. By, to achieve the above purpose.
(3) The vehicle control device according to the present invention includes an inter-vehicle distance measuring means for measuring a distance from the own vehicle to the preceding vehicle, and an instant for calculating an instantaneous relative speed between the own vehicle and the preceding vehicle based on the measured inter-vehicle distance. Relative speed calculating means, instantaneous relative speed change amount calculating means for calculating a change amount of the instantaneous relative speed, relative speed calculating means for calculating a relative speed between the own vehicle and the preceding vehicle based on the instantaneous relative speed, and the own vehicle And a control means for controlling the vehicle based on at least the relative speed calculated by the relative speed calculation means, wherein the control means controls the vehicle based on at least the relative speed calculated by the relative speed calculation means. Means for not outputting the relative speed to the control means when the change amount of the instantaneous relative speed calculated by the instantaneous relative speed change amount calculation means after the detection of the interrupted vehicle is larger than a predetermined value. By, to achieve the above purpose.
[0008]
【The invention's effect】
(1) According to the vehicle relative speed measuring device of the present invention, if the amount of change in the instantaneous relative speed after the detection of the interrupted vehicle is larger than a predetermined value, the relative speed is not calculated. When the rear part of the vehicle is captured after capturing the side surface of the interrupted vehicle, a relative speed different from the actual relative speed can be prevented from being output.
(2) According to the relative speed measuring device for a vehicle according to the present invention, the relative speed is not calculated when the amount of change in the reflected signal intensity after the detection of the interrupted vehicle is larger than a predetermined value. When the rear part of the vehicle is captured after capturing the side surface of the interrupted vehicle, a relative speed different from the actual relative speed can be prevented from being output.
(3) According to the vehicle control device of the present invention, there is provided control means for controlling the vehicle based on at least the relative speed with respect to the preceding vehicle, and the amount of change in the instantaneous relative speed after the interruption vehicle is detected is reduced. When the vehicle speed is larger than the predetermined value, the relative speed is not output to the control means, so that the vehicle based on the relative speed different from the actual relative speed when the rear portion of the vehicle is captured after capturing the side surface of the interrupted vehicle by the following distance measuring device. Control can be prevented from being performed.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
-1st Embodiment-
FIG. 1 is a diagram showing a configuration of a vehicle relative speed measuring device according to a first embodiment of the present invention. The vehicle relative speed measurement device according to the first embodiment has a laser radar 1 and a controller 2. The laser radar 1 includes a power supply circuit 3, a signal processing device 4, a drive circuit 5, a light emitting element 6, a light emitting lens 7, a light receiving lens 8, a light receiving element 9, and a light receiving circuit 10.
[0010]
The power supply circuit 3 is a circuit for supplying / cutting off a power supply voltage supplied from the outside to the laser radar 1. The signal processing device 4 includes a CPU, a ROM, a RAM, and the like. The signal processing device 4 transmits an inter-vehicle distance signal and a relative speed signal to the controller 2 and drives the driving circuit 5 to drive the light emitting element 6 based on a control signal from the controller 2. Is transmitted. The signal processing device 4 calculates a distance to the preceding vehicle based on a signal input from the light receiving circuit 10 and also calculates a relative speed V with respect to the preceding vehicle by a method described later. The drive circuit 5 drives the light emitting element 6 based on a drive signal transmitted from the signal processing device 4. The light-emitting element 6 is driven by the drive circuit 5 and emits near-infrared light having a peak of the radiation intensity around the wavelength λ = 850 to 950 mm. The pulsed light emitted from the light emitting element 6 is radiated as radiated light via the light emitting lens 7.
[0011]
The light receiving lens 8 receives light reflected by an object such as a preceding vehicle. The received light is condensed on the light receiving element 9 and is converted by the light receiving element 9 into a current corresponding to the amount of the received light. The light receiving circuit 10 amplifies the output signal of the light receiving element 9 and inputs the amplified signal to the signal processing device 4.
[0012]
The controller 2 receives an inter-vehicle distance signal and a relative speed signal transmitted from the signal processing device 4 of the laser radar, and controls various devices (such as a throttle actuator and a brake actuator) so as to keep the inter-vehicle distance to the preceding vehicle constant. (Not shown).
[0013]
The principle of measuring the inter-vehicle distance to the preceding vehicle using the laser radar 1 will be described with reference to FIG. The laser radar 1 is attached to a grill, a bumper, and the like on the front of the vehicle 11. As described above, the pulsed light emitted from the light emitting element 6 of the laser radar 1 is emitted to the front of the vehicle as the emitted light 13 via the light emitting lens 7. The emitted light 13 is reflected by the preceding vehicle 12 and returns to the laser radar 1 as reflected light 14.
[0014]
The signal processing device 4 obtains a time t from when the emitted light 13 is emitted to when the reflected light 14 is received, and calculates an inter-vehicle distance d between the host vehicle 11 and the preceding vehicle 12 from the following equation (1). .
d = (c × t) / 2 (1)
Here, c is the speed of light.
[0015]
A method for calculating the relative speed between the host vehicle 11 and the preceding vehicle 12 will be described. Since the inter-vehicle distance is calculated for each predetermined measurement cycle, the instantaneous relative speed v is calculated by dividing the difference between the currently calculated inter-vehicle distance and the previously calculated inter-vehicle distance by the measurement cycle. The relative speed V is obtained by performing a filtering process such as a moving average process on the instantaneous relative speed v. The filtering process will be described in detail.
[0016]
When the number of times of calculating the relative speed V is equal to or less than the predetermined number a, the average value of the instantaneous relative speed v is output. For example, the output V (i) when the relative speed is calculated at the i-th (i ≦ a) time is represented by the following equation (2).
V (i) = (v (i) + v (i-1) +... + V (2) + v (1)) / i (i ≦ a) (2)
Here, v (i) is the instantaneous relative speed calculated at the i-th time.
[0017]
The output V (i) when the relative speed is calculated when the number i of calculating the relative speed V is equal to or more than (a + 1) is expressed by the following equation (3).
V (i) = (k1 × v (i) + K2 × v (i−1) + K3 × v (i−2)) / (K1 + K2 + K3) (i ≧ a + 1) (3)
Here, K1, K2, and K3 are constants.
[0018]
FIG. 3 is a flowchart illustrating a relative speed calculation process performed by the vehicle relative speed measurement device according to the first embodiment. The process according to this flowchart is performed by the signal processing device 4 every 100 msec, for example. In step S10, an inter-vehicle distance to the preceding vehicle 12 is calculated by equation (1). After calculating the inter-vehicle distance, the process proceeds to step S20. In step S20, it is determined whether or not the target preceding vehicle whose inter-vehicle distance has been measured is a new measurement target vehicle (hereinafter, referred to as a new target).
[0019]
FIGS. 4A to 4C are diagrams illustrating a state where the interrupting vehicle 15 enters between the host vehicle 11 and the preceding vehicle 12 from an adjacent lane. The laser radar 1 can measure a distance to a vehicle existing in the detection area 16. As shown in FIG. 4A, when the interrupting vehicle 15 is traveling on an adjacent lane, the lane on which the own vehicle is traveling divided by two road division lines 17 (hereinafter, referred to as a traveling lane). The inter-vehicle distance d0 to the preceding vehicle 12 traveling inside is measured.
[0020]
When the vehicle 15 running on the adjacent lane is interrupted, the side surface of the interrupted vehicle 15 hits the edge of the detection area 16 as shown in FIG. The inter-vehicle distance measured in this case is the distance d1 to the point where the side surface of the vehicle 15 and the edge of the detection area 16 intersect. Thereafter, as shown in FIG. 4C, when the interrupted vehicle 15 enters the detection area 16, the inter-vehicle distance measured by the laser radar 1 becomes d2.
[0021]
FIGS. 5A to 5D show an inter-vehicle distance and an instantaneous relative speed calculated when the interrupting vehicle 15 enters the traveling lane, as shown in FIGS. 4A to 4C. FIG. 7 is a diagram illustrating an instantaneous relative speed fluctuation amount and a relative speed after filtering. As shown in FIG. 5A, d0 is detected as the inter-vehicle distance to the preceding vehicle until time t1, but d1 is measured when the interrupting vehicle 15 enters, and at the next distance measurement cycle, d2 is measured.
[0022]
The determination in step S20 is made based on the amount of change in the following distance. If the amount of change in the following distance is small, it is determined that the detected target is not a new target, and the process proceeds to step S30. In step S30, the instantaneous relative speed v is calculated based on the inter-vehicle distance calculated this time and the inter-vehicle distance calculated last time. After calculating the instantaneous relative speed v, the process proceeds to step S40. In step S40, the above-described filtering process is performed, and the flow advances to step S190.
[0023]
On the other hand, as shown in FIG. 5A, when the amount of change in the inter-vehicle distance is large (d0 → d1), it is determined that the detected target is a new target, and the process proceeds from step S20 to step S50. In step S50, the filtering process performed when calculating the relative speed V is reset. As described above, the relative speed V is not calculated by resetting the filtering process using the instantaneous relative speed v calculated in the past. In step S60, the number of calculations i for performing the filtering process is set to 0, and the process proceeds to step S70.
[0024]
In step S70, 1 is added to the number of calculations i for performing the filter processing, and the process proceeds to step S80. In step S80, the same process as in step S10, that is, the inter-vehicle distance to the preceding vehicle 12 is calculated. After calculating the inter-vehicle distance, the process proceeds to step S90. In step S90, the same determination as in step S20, that is, whether or not the target whose inter-vehicle distance has been measured is a new target is determined. If it is determined that the target is a new target, the process returns to step S50. If it is determined that the target is not a new target, the process proceeds to step S100.
[0025]
The reason for determining again whether or not the target is a new target in step S90 is that when the interrupting vehicle 15 stops interrupting, the preceding vehicle 12 existing on the own lane is detected. is there. In such a case, the process returns to step S50, and the process of measuring the inter-vehicle distance is performed again (step S80). For example, the state shown in FIG. 4 (a) is shifted to the state shown in FIG. 4 (b), and after it is determined in step S20 that the target is a new target, the distance between the vehicles in the state shown in FIG. When the distance measurement (step S80) is performed, the change in the inter-vehicle distance when the state of FIG. 4 (b) shifts to the state of FIG. 4 (c) is small (d1 → d2). In the determination, it is determined that the target is not a new target.
[0026]
In step S100, the instantaneous relative speed v is calculated using the previously calculated inter-vehicle distance (the inter-vehicle distance calculated in step S10) and the inter-vehicle distance calculated this time (the inter-vehicle distance calculated in step S80). . After calculating the instantaneous relative speed v, the process proceeds to step S110. In step S110, the variation Δv of the instantaneous relative speed v is calculated. FIG. 5C is a diagram showing a variation Δv of the instantaneous relative speed v calculated based on the instantaneous relative speed v of FIG. 5B. After calculating the variation Δv of the instantaneous relative speed v, the process proceeds to step S120.
[0027]
In step S120, it is determined whether or not the variation Δv of the instantaneous relative speed v calculated in step S110 exceeds a predetermined value α. As shown in FIG. 5C, when the variation Δv exceeds the predetermined value α, it is determined by the laser radar 1 that the measurement point has moved from the side of the vehicle to the rear of the vehicle, and the process proceeds to step S130. If it does not exceed the value α, the process proceeds to step S150. In step S130, the filtering process is reset, and the process proceeds to step S140. In step S140, the above-described filtering process is performed, and the process proceeds to step S190. In step S190, the relative speed after the filter processing is output.
[0028]
FIG. 5D is a diagram illustrating the output of the relative speed after the filtering process. As shown in FIG. 5C, when the variation Δv of the instantaneous relative speed v exceeds the predetermined value α, the filtering process is reset, and during this period (from time t1 to t2), the relative speed is reduced. V is not output. That is, when the relative speed V is output, it is guaranteed that an accurate value is output. It is preferable that control such as keeping the vehicle speed constant is performed between times t1 and t2 when the relative speed V is not output.
[0029]
As described above, as shown in FIG. 4A to FIG. 4C, when the vehicle 15 interrupts from the adjacent lane, the filtering process is reset based on the variation Δv of the instantaneous relative speed v. , Can output an accurate relative speed. However, when the interrupting vehicle 15 slowly enters the own lane, the filtering process may not be reset because the variation amount Δv of the instantaneous relative speed v is small.
[0030]
FIG. 6A to FIG. 6F are diagrams showing a situation in which the vehicle 15 is slowly interrupting between the host vehicle 11 and the preceding vehicle 12. In this case, when the inter-vehicle distance is measured, the side surface of the vehicle 15 is continuously detected as a measurement point (FIGS. 6B to 6E), and thus the fluctuation amount Δv of the instantaneous relative speed v also becomes a small value. . Therefore, even in such a case, a process for accurately outputting the relative speed V is performed in steps S150 to S180 in the flowchart of FIG.
[0031]
In step S150, the variation Δp of the amount of reflected light received by the light receiving element 9 is calculated. The amount of reflected light received will be described. As shown in FIG. 7, a normal vehicle is equipped with a reflection reflector 18 at the rear of the vehicle. The reflection reflector 18 has a characteristic of reflecting incident light in the incident direction, and therefore generally has a very high reflectance. On the other hand, the reflectivity of the vehicle side is not so high, and the radiation emitted from the laser radar 1 does not enter the vehicle side perpendicularly, so that the light reflected on the vehicle side is reflected in a different direction from the laser radar 1. Cheap. Therefore, there is a large difference between the amount of light received from the reflector 18 and the amount of light received from the side of the vehicle.
[0032]
FIGS. 8A to 8F show an inter-vehicle distance, an instantaneous relative speed v, and an instantaneous relative speed when the vehicle 15 is slowly interrupted, as shown in FIGS. 6A to 6F. It is a figure which shows the variation | change_quantity (DELTA) v, the reflected light reception amount p, the variation | change_quantity (DELTA) p of reflected light reception amount, and the relative speed output after filtering. Since the vehicle 15 interrupts slowly, the instantaneous relative speed v and the variation Δv of the instantaneous relative speed v are small. On the other hand, the reflected light reception amount p is small while the side surface of the vehicle 15 is at the measurement point, but increases rapidly when the reflection reflector 18 of the vehicle 15 enters the detection area 16. Therefore, the variation Δp of the reflected light reception amount shows a large value when the laser radar 1 receives the reflected light from the reflection reflector 18, that is, when the rear part of the vehicle 15 is captured by the laser radar 1.
[0033]
Returning to the flowchart of FIG. 3, the description will be continued. After calculating the variation Δp of the reflected light reception amount in step S150, the process proceeds to step S160. In step S160, it is determined whether or not the variation Δp calculated in step S150 is larger than a predetermined value β. As shown in FIG. 8E, when the variation Δp exceeds the predetermined value β, the process proceeds to step S130, and the filtering process is reset. On the other hand, if it is determined that the variation Δp is equal to or smaller than the predetermined value β, the process proceeds to step S170.
[0034]
In step S170, the filtering process is continuously performed. In the next step S180, it is determined whether or not the number of calculations i for performing the filter processing has exceeded a predetermined value n. When it is determined that the difference does not exceed the predetermined value n, the process returns to step S70, where the above-described variation Δv of the instantaneous relative speed is compared with the predetermined value α, and the variation Δp of the reflected light reception amount is compared with the predetermined value β. If it is determined that the number of calculations i has exceeded the predetermined value n, the process proceeds to step S190, and the relative speed V is output.
[0035]
Under actual driving conditions, the rear part of the interrupting vehicle 15 is often grasped from the beginning when the vehicle 15 interrupts. In such a case, the variation Δv of the instantaneous relative speed and the variation Δp of the reflected light reception amount are likely to be very small. Accordingly, by setting a limit (n) on the number i of filter processing operations after detecting a new target, it is possible to prevent the relative speed V from being output forever. That is, the filter processing is reset when the fluctuation amount Δv of the instantaneous relative speed exceeds the predetermined value α in step S120 or the fluctuation amount Δp in the reflected light reception amount exceeds the predetermined value β in step S160. This is a case where the number of operations i is equal to or less than a predetermined value n. Since the calculation of the filter processing is usually performed in a fixed time, in other words, if the fluctuation amount Δv of the instantaneous relative speed exceeds a predetermined value α within a predetermined time after a new target is detected, Alternatively, when the variation Δp of the reflected light reception amount exceeds the predetermined value β, the filtering process is reset.
[0036]
According to the vehicle relative speed measurement device of the first embodiment, when the variation amount Δv of the instantaneous relative speed exceeds a predetermined value α after a new target is detected, the filtering process for calculating the relative speed is performed. Since the reset is performed, it is possible to prevent a relative speed different from the actual relative speed from being output when the rear side of the vehicle is captured after the side surface of the interrupted vehicle 15 is captured by the laser radar 1 (FIG. 5 ( d)).
[0037]
Further, when the variation Δp of the reflected light reception amount exceeds the predetermined value β, the filter processing for calculating the relative speed is reset, so that the interrupted vehicle 15 can be interrupted slowly, and the variation Δv of the instantaneous relative speed becomes smaller than the predetermined value. Even when the value does not exceed the value α, the output of a relative speed different from the actual relative speed can be prevented (see FIG. 8F).
[0038]
Further, after the new target is detected, until the number of times i of the filtering process exceeds a predetermined number n, the filtering process is performed based on the variation amount Δv of the instantaneous relative speed and / or the variation amount Δp of the reflected light reception amount. Is determined, and if the number of calculations i exceeds a predetermined number n, the relative speed is output. Therefore, when the variation Δv of the instantaneous relative speed and the variation Δp of the reflected light reception amount do not exceed the predetermined values. It is possible to prevent the relative speed from being output forever.
[0039]
When the interrupted vehicle 15 is detected, a method of not outputting the relative speed for a predetermined time may be considered. However, in this method, when the interrupted vehicle 15 is detected, the relative speed is always output until the relative speed is output. A time delay will occur. According to the vehicle relative speed measurement device of the first embodiment, the presence or absence of the reset of the filtering process is determined based on both or one of the variation Δv of the instantaneous relative speed and the variation Δp of the reflected light reception amount. , The filtering is reset only when necessary. That is, as described above, a delay of a predetermined time does not always occur until the relative speed is output.
[0040]
FIG. 10A shows the inter-vehicle distance when the vehicle 15 running in the adjacent lane has cut in front of the host vehicle 11 as shown in FIGS. 4A to 4C. . FIG. 10B shows the relative speed calculated by the method of the related art based on the following distance shown in FIG. When the vehicle 15 is interrupted, the inter-vehicle distance changes greatly from d0 to d1, so that the target is detected as a new target, and the relative speed calculation process is reset. However, since the difference between the distance d1 to the side of the vehicle 15 and the distance d2 to the rear of the vehicle is small, the relative speed calculation processing is not reset. As a result, when the inter-vehicle distance shifts from d1 to d2, a very large relative speed in the approaching direction (direction in which the preceding vehicle decelerates) is detected. That is, in the filter processing for calculating the relative speed, the instantaneous relative speed calculated in the past is used, so that the instantaneous relative speed when the inter-vehicle distance shifts from d1 to d2 is used a predetermined number of times, and the error is incorrect. The relative speed is output for a long time. However, according to the vehicle relative speed measurement device in the present embodiment, it is possible to prevent an erroneous relative speed from being output as described above.
[0041]
-2nd Embodiment-
The configuration of the vehicle relative speed measurement device according to the second embodiment is the same as the configuration of the vehicle relative speed measurement device according to the first embodiment shown in FIG. The content of the relative speed calculation process performed by the vehicle relative speed measurement device according to the second embodiment will be described with reference to the flowchart shown in FIG. Processing having the same contents as the processing performed in the flowchart shown in FIG. 3 is denoted by the same reference numeral, and detailed description is omitted.
[0042]
The processing from step S10 to step S120 is the same as the processing performed in the flowchart shown in FIG. 3, and a description thereof will be omitted. If it is determined in step S120 that the variation amount Δv of the instantaneous relative speed has exceeded the predetermined value α, the process proceeds to step S150, and if it is determined that the variation amount Δv does not exceed the predetermined value α, the process proceeds to step S170. In step S150, the variation Δp of the reflected light reception amount p received by the light receiving element 9 is calculated, and the process proceeds to step S160. In step S160, it is determined whether or not the variation Δp of the reflected light reception amount p calculated in step S150 has exceeded a predetermined value β. If it is determined that the fluctuation amount Δp has exceeded the predetermined value β, the process proceeds to step S130 to reset the filtering process. On the other hand, if it is determined that the fluctuation amount Δp does not exceed the predetermined value β, the process proceeds to step S170, and the filtering process is continuously performed.
[0043]
That is, in the vehicle relative speed measuring device according to the second embodiment, the variation Δv of the instantaneous relative speed exceeds the predetermined value α, and the variation Δp of the reflected light reception amount exceeds the predetermined value β. In such a case, the filter processing for calculating the relative speed V is reset. As a result, it is possible to reliably detect a situation in which the rear side of the vehicle is captured after the laser radar 1 captures the side surface of the interrupted vehicle 15.
[0044]
The processing performed by the vehicle relative speed measuring device according to the second embodiment is also effective when the vehicle 15 running on the adjacent lane suddenly decelerates immediately after the interruption. In the process according to the flowchart shown in FIG. 3, when the interrupted vehicle 15 suddenly decelerates immediately, the instantaneous relative speed v greatly changes. Therefore, depending on the value of the predetermined value α, the interrupted vehicle 15 suddenly decelerates. The filtering may be reset during the operation. When the filtering process is reset, the relative speed V is not output, so that it becomes impossible to perform the following distance control based on the relative speed V.
[0045]
However, according to the processing according to the flowchart shown in FIG. 9, since the filter processing is reset based on the fluctuation amount Δv of the instantaneous relative speed and the fluctuation amount Δp of the reflected light reception amount, when the interrupted vehicle 15 suddenly decelerates, This can prevent the filtering process from being reset. That is, when the interrupting vehicle 15 is rapidly decelerating, since the interrupting operation from the adjacent lane has been completed, the variation Δp of the reflected light reception amount is small. Therefore, even when the condition of Δv> α is satisfied, the condition of Δp> β is not satisfied, so that resetting of the filtering process can be prevented.
[0046]
Further, the processing performed by the vehicle relative speed measuring device according to the second embodiment is effective even in a situation where the reflection reflector 18 of the interrupted vehicle 15 moves in and out of the detection area 16 of the laser radar 1. In such a situation, the amount of reflected light received fluctuates greatly. Therefore, in the method of resetting the filter processing based only on the amount of change Δp in the amount of reflected light received, the filter processing is reset even when the rear part of the vehicle is continuously captured. there is a possibility. However, if the filter processing is reset when both the conditions of Δv> α and Δp> β are satisfied, as in the processing performed in the second embodiment, in the above described situation, The filter processing will not be easily reset.
[0047]
The present invention is not limited to the above embodiment. For example, in the flowchart shown in FIG. 3, when the variation Δv of the instantaneous relative speed is equal to or smaller than the predetermined value α, the magnitude of the variation Δp of the reflected light reception amount is compared with the predetermined value β. May be determined whether or not the variation Δp is larger than a predetermined value β. In this case, regardless of the magnitude of the variation amount Δv of the instantaneous relative speed, the filtering process is reset when the variation amount Δp of the reflected light reception amount exceeds the predetermined value β.
[0048]
Further, the method of the filtering process for calculating the relative speed has been described using equations (2) and (3), but a method other than the above-described method may be used. For example, the filtering process can be performed using a transfer function T (s) shown in the following equation (4).
T (s) = 1 / (τs + 1) (4)
Furthermore, although the laser light transmitted from the laser radar 1 has been described as near-infrared light, the present invention is not limited by the type of laser light.
[0049]
The correspondence between the components of the claims and the components of the embodiment is as follows. That is, the laser radar 1 uses the inter-vehicle distance measuring unit and the interrupting vehicle detecting unit, and the signal processing device 4 uses the instantaneous relative speed calculating unit, the instantaneous relative speed change amount calculating unit, the relative speed calculating unit, and the reflected signal intensity change amount detection. The controller 2 constitutes the control means. Note that each component is not limited to the above configuration as long as the characteristic functions of the present invention are not impaired.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a vehicle relative speed measurement device according to a first embodiment.
FIG. 2 is a diagram for explaining a measurement principle of inter-vehicle distance measurement.
FIG. 3 is a flowchart illustrating processing performed by the vehicle relative speed measurement device according to the first embodiment;
FIGS. 4 (a) to 4 (c) show how a vehicle running in an adjacent lane is interrupted.
5 (a) is a diagram showing an inter-vehicle distance, FIG. 5 (b) is a diagram showing an instantaneous relative speed, and FIG. 5 (c) under the conditions shown in FIGS. 4 (a) to 4 (c). ) Shows the variation of the instantaneous relative speed, and FIG. 5D shows the relative speed output after filtering.
6 (a) to 6 (f) are diagrams showing a situation where a vehicle running in an adjacent lane is slowly interrupting.
FIG. 7 is a diagram showing a reflection reflector provided at a rear portion of the vehicle.
8 (a) is a diagram showing an inter-vehicle distance, FIG. 8 (b) is a diagram showing an instantaneous relative speed, and FIG. 8 (c) under the conditions shown in FIGS. 6 (a) to 6 (f). 8) shows the amount of change in the instantaneous relative speed, FIG. 8 (d) shows the amount of reflected light, FIG. 8 (e) shows the amount of change in the amount of reflected light, and FIG. Diagram showing the relative speed output of
FIG. 9 is a flowchart illustrating processing performed by a vehicle relative speed measurement device according to a second embodiment.
10 (a) is a diagram showing an inter-vehicle distance and FIG. 10 (b) is a diagram showing a relative speed calculated by a conventional technique under the conditions shown in FIGS. 4 (a) to 4 (c).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Laser radar, 2 ... Controller, 3 ... Power supply circuit, 4 ... Signal processing device, 5 ... Drive circuit, 6 ... Light emitting element, 7 ... Light emitting lens, 8 ... Light receiving lens, 9 ... Light receiving element, 10 ... Light receiving Circuit, 11: own vehicle, 12: preceding vehicle, 13: emitted light, 14: reflected light, 15: interrupted vehicle, 16: detection area, 17: road dividing line, 18: reflective reflector

Claims (9)

An inter-vehicle distance measuring means for measuring a distance from the own vehicle to a preceding vehicle;
Based on the inter-vehicle distance measured by the inter-vehicle distance measurement means, an instantaneous relative speed calculation means for calculating an instantaneous relative speed between the own vehicle and the preceding vehicle,
An instantaneous relative speed change amount calculating means for calculating a change amount of the instantaneous relative speed calculated by the instantaneous relative speed calculating means,
Based on the instantaneous relative speed calculated by the instantaneous relative speed calculation means, a relative speed calculation means for calculating a relative speed between the own vehicle and the preceding vehicle,
An interrupting vehicle detecting means for detecting a vehicle interrupting between the own vehicle and the preceding vehicle,
The relative speed calculation means, when the change amount of the instantaneous relative speed calculated by the instantaneous relative speed change amount calculation means after the interrupted vehicle is detected by the interrupting vehicle detection means is larger than a predetermined value, A relative speed measuring device for a vehicle, wherein a relative speed is not calculated. The vehicle relative speed measurement device according to claim 1,
The relative speed calculation means calculates the relative speed by performing a filtering process on the instantaneous relative speed calculated by the instantaneous relative speed calculation means, and calculates the relative speed after the interrupted vehicle is detected by the interrupted vehicle detection means. A relative speed measuring device for a vehicle, wherein the filter processing is reset when a change amount of the instantaneous relative speed calculated by the instantaneous relative speed change amount calculating means is larger than a predetermined value. The vehicle relative speed measuring device according to claim 1 or 2,
The relative speed calculating means is configured such that, within a predetermined time after the interrupted vehicle is detected by the interrupting vehicle detecting means, a change amount of the instantaneous relative speed calculated by the instantaneous relative speed change amount calculating means is larger than a predetermined value. In such a case, the relative speed is not calculated. Signal sending means for sending a signal forward of the vehicle;
An inter-vehicle distance measuring unit that measures a distance from the own vehicle to a preceding vehicle based on the signal transmitted from the signal transmitting unit;
Reflected signal intensity change amount detection means for detecting the intensity change amount of the reflected signal of the signal transmitted by the signal transmission means,
Based on the inter-vehicle distance measured by the inter-vehicle distance measurement means, an instantaneous relative speed calculation means for calculating an instantaneous relative speed between the own vehicle and the preceding vehicle,
Based on the instantaneous relative speed calculated by the instantaneous relative speed calculation means, a relative speed calculation means for calculating a relative speed between the own vehicle and the preceding vehicle,
An interrupting vehicle detecting means for detecting a vehicle interrupting between the own vehicle and the preceding vehicle,
The relative speed calculating means is provided when the change amount of the reflected signal intensity detected by the reflected signal intensity change amount detecting means after the interruption vehicle is detected by the interrupting vehicle detecting means is larger than a first predetermined value. Does not calculate the relative speed. The vehicle relative speed measuring device according to claim 4,
The relative speed calculation means calculates the relative speed by performing a filtering process on the instantaneous relative speed calculated by the instantaneous relative speed calculation means, and calculates the relative speed after the interrupted vehicle is detected by the interrupted vehicle detection means. A relative speed measuring device for a vehicle, wherein the filter processing is reset when a change amount of the reflected signal intensity detected by the reflected signal intensity change amount detecting means is larger than a first predetermined value. The vehicle relative speed measuring device according to claim 4 or 5,
The relative speed calculating means determines that a change in the reflected signal strength detected by the reflected signal strength change detecting means within a predetermined time after the interrupted vehicle is detected by the interrupting vehicle detecting means is equal to a first predetermined value. If the value is larger than the value, the relative speed is not calculated. The vehicle relative speed measuring device according to any one of claims 4 to 6,
Further comprising an instantaneous relative speed change amount calculating means for calculating a change amount of the instantaneous relative speed calculated by the instantaneous relative speed calculating means,
The relative speed calculating means is configured such that a change amount of the reflected signal intensity detected by the reflected signal intensity change amount detecting means after the interruption vehicle is detected by the interrupting vehicle detecting means is larger than a first predetermined value, and A relative speed measuring device for a vehicle, wherein the relative speed is not calculated when the change amount of the instantaneous relative speed calculated by the instantaneous relative speed change amount calculating means is larger than a second predetermined value. The vehicle relative speed measuring device according to any one of claims 2, 3, 5, 6, and 7,
The filtering process performed by the relative speed calculation unit is performed based on the instantaneous relative speeds from the present instantaneous relative speed to a predetermined number of times before in the past among the instantaneous relative speeds calculated by the instantaneous relative speed calculation unit. A relative speed measuring device for a vehicle, which is a process of calculating a relative speed. An inter-vehicle distance measuring means for measuring a distance from the own vehicle to a preceding vehicle;
Based on the inter-vehicle distance measured by the inter-vehicle distance measurement means, an instantaneous relative speed calculation means for calculating an instantaneous relative speed between the own vehicle and the preceding vehicle,
An instantaneous relative speed change amount calculating means for calculating a change amount of the instantaneous relative speed calculated by the instantaneous relative speed calculating means,
Based on the instantaneous relative speed calculated by the instantaneous relative speed calculation means, a relative speed calculation means for calculating a relative speed between the own vehicle and the preceding vehicle,
Interrupting vehicle detecting means for detecting a vehicle interrupting between the host vehicle and the preceding vehicle;
Control means for controlling the vehicle based on at least the relative speed calculated by the relative speed calculation means,
The relative speed calculation means, when the change amount of the instantaneous relative speed calculated by the instantaneous relative speed change amount calculation means after the interrupted vehicle is detected by the interrupting vehicle detection means is larger than a predetermined value, A control device for a vehicle, wherein a relative speed is not output to the control means.

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