JP2005096675A - Following travel control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve safety at turning right or left and improvement of fuel consumption in a following travel control device for following a preceding vehicle while a predetermined following distance is maintained. <P>SOLUTION: When a stop state of an own vehicle is detected and turning right or left of the own vehicle is foreseen in a state of following travel to the preceding vehicle, a shift position or a shift ratio of a transmission at starting is made to be a second speed position or a shift ratio corresponding to the second speed. Therefore, starting and acceleration can be made to be mild, and the vehicle can immediately stop when the vehicle meets an obstacle such as a person or a bicycle at turning right or left just after starting. Further, the fuel consumption can be improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a follow-up control device that follows a preceding vehicle while maintaining a constant inter-vehicle distance.

  There is known a preceding vehicle follow-up control device in which the start and stop are repeated at a low speed on a congested road and the fuel consumption is improved compared to the case where the second speed start is repeated and the first speed start is repeated (for example, patents) Reference 1).

Prior art documents related to the invention of this application include the following.
JP 2001-268111 A

  However, in the conventional preceding vehicle follow-up control device described above, for example, when the preceding vehicle quickly stops when the vehicle stops after the preceding vehicle at the intersection and the signal changes and the preceding vehicle starts to turn right or left, In spite of making a right turn or a left turn, it is conceivable that the first vehicle starts with the quick movement of the preceding vehicle. For this reason, there is a problem that not only fuel consumption cannot be saved, but also the intersection is turned right and left vigorously, which is undesirable from the protection of pedestrians and the like.

  When the vehicle is in a state of following the preceding vehicle, when the vehicle's stop state is detected and the vehicle's vehicle is predicted to turn left or right, the shift position or the gear ratio of the transmission at the start is set to the second speed position. Or it is set as the gear ratio corresponding to the second speed.

  According to the present invention, start acceleration is moderated, and even if an obstacle such as a person or a bicycle is encountered when turning right or left immediately after starting, the vehicle can be stopped immediately and fuel efficiency can be improved.

  FIG. 1 shows the configuration of an embodiment. The engine control device 1 performs throttle valve opening / closing control, fuel injection control, ignition timing control, and the like of the engine 2 to control the rotational speed and output torque of the engine 2. The transmission control device 3 controls the gear ratio of the automatic transmission 4, that is, the shift position. In this embodiment, an automatic transmission having first, second, third, D (drive), R (reverse) and P (parking) shift positions will be described as an example. The brake control device 5 controls the brake fluid pressure Pbk to adjust the braking force. The driving force of the engine 2 is transmitted to the drive wheels 7a and 7b via the automatic transmission 4 and the speed reducer 6, and a brake device (not shown) is provided for each of the drive wheels 7a and 7b and the driven wheel (not shown). Is provided.

  The follow-up control controller 8 performs the follow-up running control while maintaining a constant distance from the preceding vehicle when the preceding vehicle is recognized on the own lane, and at a preset vehicle speed when there is no preceding vehicle. Car speed control is performed. The tracking control controller 8 is connected to an inter-vehicle distance sensor 9, a vehicle speed sensor 10, an engine rotation speed sensor 11, a navigation device 12, an input device 13, a display device 14, a direction indicator 15, and the like.

  The inter-vehicle distance sensor 9 receives the reflected light from the preceding vehicle by scanning the laser beam in the left-right direction in front of the vehicle. The inter-vehicle distance sensor 9 is not limited to the laser radar, but may be a millimeter wave radar or an ultrasonic radar. The vehicle speed sensor 10 is attached to the output shaft of the automatic transmission 4 and outputs a pulse signal having a period corresponding to the rotational speed. The engine rotation speed sensor 11 detects the rotation speed of the engine 2.

  The navigation device 12 detects the current location of the host vehicle, searches for the optimal route from the current location to the destination, displays the road map around the current location, the optimal route, and the current location on the display device 14 to perform route guidance. The input device 13 includes an operation member for inputting a destination for route guidance, a vehicle speed command value for vehicle speed control, and the like, and operating a display screen of the display device 14.

  As shown in FIG. 2, the tracking control controller 8 includes a control unit configured by a software form of a microcomputer. The ranging signal processing unit 81 recognizes a forward object on the own lane as a preceding vehicle by the inter-vehicle distance sensor 9, measures the time from receiving the laser beam to receiving the reflected light of the preceding vehicle, and measures the preceding vehicle. The inter-vehicle distance L is detected. The vehicle speed signal processing unit 82 measures the cycle of the vehicle speed pulse signal from the vehicle speed sensor 10 and detects the speed Vs of the host vehicle.

The relative speed calculation unit 83 calculates a relative speed ΔV with respect to the preceding vehicle based on the inter-vehicle distance L from the ranging signal processing unit 81. The inter-vehicle distance control unit 84 calculates a target vehicle speed V ^* for making the inter-vehicle distance L coincide with the target inter-vehicle distance L ^* in consideration of the relative speed ΔV. The target inter-vehicle distance setting unit 85 sets a target inter-vehicle distance L ^* corresponding to the host vehicle speed Vs. The vehicle speed control unit 86 calculates a driving force, a braking force, and a gear ratio for making the host vehicle speed Vs coincide with the target vehicle speed V ^* , and controls the engine control device 1, the transmission control device 3, and the brake control device 5.

  FIG. 3 is a flowchart showing the follow-up control program according to the embodiment. The operation of the embodiment will be described with reference to this flowchart. The tracking control controller 8 executes the tracking control program shown in FIG. 3 every 10 msec, for example.

  In step 1, it is confirmed whether or not a preceding vehicle is detected. When a preceding vehicle is detected by the inter-vehicle distance sensor 9 and the distance measurement signal processing unit 81, the process proceeds to step 3, and when a preceding vehicle is not detected Goes to step 2. When the preceding vehicle is not detected, vehicle speed control is performed at step 2. That is, the braking / driving force and the gear ratio for making the host vehicle speed Vs coincide with a preset vehicle speed command value are calculated, and the engine control device 1, the transmission control device 3, and the brake control device 5 are controlled.

On the other hand, when the preceding vehicle has been detected, it sets the target inter-vehicle distance L ^* in accordance with the vehicle speed Vs by the target inter-vehicle distance setting section 85 in step 3. The target inter-vehicle distance setting unit 85 stores a map of the target inter-vehicle distance with respect to the own vehicle speed, and calculates a target inter-vehicle distance according to the own vehicle speed Vs detected by the vehicle speed sensor 10 and the vehicle speed signal processing unit 82, It is set as the target inter-vehicle distance L ^* for the follow-up traveling control.

Next, in step 4, the inter-vehicle distance control unit 84 performs inter-vehicle distance control. That is, the target vehicle speed V ^* for making the inter-vehicle distance L coincide with the target inter-vehicle distance L ^* in consideration of the relative speed ΔV with the preceding vehicle calculated by the relative speed calculation unit 83 is calculated. In the following step 5, the vehicle speed control unit 86 performs vehicle speed control for follow-up running. That is, the driving force, braking force, and gear ratio for making the host vehicle speed Vs coincide with the target vehicle speed V ^* are calculated.

  In step 6, it is confirmed whether or not the vehicle is stopped. If the vehicle speed Vs detected by the vehicle speed sensor 10 and the vehicle speed signal processing unit 82 is equal to or less than a predetermined value Vo near 0, it is determined that the vehicle is stopped. When it is determined that the vehicle is not stopped, the routine proceeds to step 13 where the calculated driving force, braking force, and gear ratio are output to the engine control device 1, the transmission control device 3, and the brake control device 5 to perform follow-up running control. .

Meanwhile, when it is determined that the vehicle is stopped the process proceeds to step 7 calculates the target acceleration G ^*. The target acceleration G ^* may be obtained by differentiating the target vehicle speed V ^* . In the following step 8, it is confirmed whether or not the target acceleration G ^* is not less than the lower limit value Go. The lower limit value Go is set to a moderate acceleration, such as 0.05 [G], so that the vehicle can stop immediately after recognizing a pedestrian or bicycle after starting. If the target acceleration G ^* is greater than or equal to the lower limit value Go and relatively rapid acceleration is necessary, the process proceeds to step 9; otherwise, the process proceeds to step 11.

When the target acceleration G ^* is less than the lower limit Go and the acceleration is moderate, the second speed is set as the shift position in Step 11 and the driving force and braking force calculated in Step 13 are used as the engine control device 1 and the brake control device 5. And the set shift position (= second speed) is output to the transmission control device 3 to perform follow-up running control and start follow-up running at the second speed. Thereby, the fuel consumption can be improved.

On the other hand, if the target acceleration / deceleration G ^* is greater than or equal to the lower limit Go and relatively rapid acceleration is required, it is confirmed in step 9 whether or not the distance to the next intersection is, for example, 20 m or less. The navigation device 12 detects the distance from the current location of the vehicle to the next intersection of the traveling road. If the distance to the intersection is 20 m or less, the process proceeds to step 10; otherwise, the process proceeds to step 12.

  If the distance to the next intersection is longer than 20 m, the first speed is set as the shift position in step 12 and the driving force and braking force calculated in step 13 are output to the engine control device 1 and the brake control device 5. At the same time, the set shift position (= first speed) is output to the transmission control device 3 to perform follow-up running control and start follow-up running with the first speed. Under a situation where rapid acceleration is required, if the second speed start is performed when the distance to the next intersection is longer than 20 m, the occupant feels uncomfortable, so the first speed start is performed.

  If the distance to the next intersection is 20 m or less, it is checked in step 10 whether to make a right turn or a left turn at the next intersection. It may be predicted that there is a right / left turn if the turn indicator 15 is operated to turn right or left, or the right at the next intersection based on the guidance route to the destination set by the navigation device 12. A left turn may be predicted. If there is a right or left turn at the next intersection, go to Step 11; otherwise go to Step 12.

  If there is no right or left turn at the next intersection, the first speed is set to the shift position in step 12, and the driving force and braking force calculated in step 13 are output to the engine control device 1 and the brake control device 5, and The set shift position (= 1st speed) is output to the transmission control device 3, and follow-up running control is performed, and follow-up running is started at the first speed start. In a situation where the distance to the next intersection is 20 m or less and the preceding vehicle has started quickly, and relatively quick acceleration is required, if the vehicle starts straight at the second speed, the passenger feels uncomfortable. Under such circumstances, the first speed is started.

  If there is a left or right turn at the next intersection, the second speed is set at the shift position in step 11, and the driving force and braking force calculated in step 13 are output to the engine control device 1 and the brake control device 5, and The set shift position (= second speed) is output to the transmission control device 3, and follow-up running control is performed to start follow-up running at the second speed start. That is, even when the distance to the next intersection is 20 m or less and the preceding vehicle has started quickly, when making a right turn or left turn at the intersection, the vehicle starts at the second speed and accelerates slowly. Thereby, even if it meets a pedestrian or a bicycle at the time of turning left and right, the vehicle can be stopped with a margin and fuel efficiency can be improved.

  As described above, according to the embodiment, when the vehicle is in a state of following the preceding vehicle, when the stop state of the own vehicle is detected and the left or right turn of the own vehicle is predicted, the speed change at the start Since the speed change position of the machine is set to the 2nd speed position, the start acceleration is moderate, and even if it encounters an obstacle such as a person or a bicycle when turning right or left immediately after starting, it can stop immediately and improve fuel efficiency Can be made.

  Moreover, according to one embodiment, when it is determined that rapid acceleration is required after the start and the distance to the intersection exceeds a predetermined distance (for example, 20 m), even if a right / left turn is predicted, Since the speed change position of the transmission at the time of start is set to the first speed position, the passenger is not discomforted.

  The correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the inter-vehicle distance sensor 9 is the inter-vehicle distance detection means, the follow-up control controller 8 is the follow-up running control means, the start control means and the sudden acceleration determination means, the vehicle speed sensor 10 is the stop detection means, the direction indicator 15 or the navigation device 12. The right and left turn prediction means, and the navigation device 12 constitutes a distance detection means. In addition, as long as the characteristic function of this invention is not impaired, each component is not limited to the said structure.

  In the above-described embodiment, the stepped automatic transmission 4 has been described as an example. However, the present invention can be applied to an automobile equipped with a continuously variable transmission such as a CVT. In that case, the above-described starting operation may be performed by setting the transmission ratio corresponding to the first speed of the stepped automatic transmission or the transmission ratio corresponding to the second speed in the continuously variable transmission. Here, the gear ratio equivalent to the first gear is a gear ratio used in normal starting. The gear ratio corresponding to the first speed is not a fixed ratio, and the gear ratio may be slightly changed depending on the situation. The gear ratio corresponding to the second speed is a gear ratio on the higher gear side than the gear ratio corresponding to the first speed described above. Like the gear ratio corresponding to the first speed, the gear ratio is not fixed, and the gear ratio is slightly changed depending on the situation. May be.

  Further, in the above-described embodiment, the example of right / left turn at an intersection has been described as an example. However, the present invention is not limited to right / left turn at an intersection. However, the present invention can be applied.

  Furthermore, although an embodiment has been described by taking an automobile equipped with an engine as an example, the present invention is not limited to an engine vehicle, and can be applied to an electric vehicle and a hybrid vehicle.

It is a figure which shows the structure of one embodiment. It is a figure which shows the structure of a tracking control controller. It is a flowchart which shows the tracking control program of one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine control apparatus 2 Engine 3 Transmission control apparatus 4 Automatic transmission 5 Brake control apparatus 6 Reducer 7a, 7b Drive wheel 8 Follow-up control controller 9 Inter-vehicle distance sensor 10 Vehicle speed sensor 11 Engine rotational speed sensor 12 Navigation apparatus 13 Input apparatus 14 Display device 81 Ranging signal processor 82 Vehicle speed signal processor 83 Relative speed calculator 84 Inter-vehicle distance controller 85 Target inter-vehicle distance setting unit 86 Vehicle speed controller

Claims (3)

An inter-vehicle distance detecting means for recognizing a preceding vehicle and detecting an inter-vehicle distance;
In a follow-up travel control device comprising follow-up travel control means for controlling the prime mover and the transmission so as to follow the preceding vehicle so that the inter-vehicle distance detection value becomes the target inter-vehicle distance,
Stop detection means for detecting the stop state of the own vehicle;
A right / left turn prediction means for predicting a right / left turn of the own vehicle;
When the vehicle is in a state of following the preceding vehicle and the stop state is detected by the stop detection unit and the right / left turn is predicted by the right / left turn prediction unit, the shift position or the transmission ratio of the transmission at the start And a start control means for setting the gear ratio to the second speed position or a gear ratio corresponding to the second speed. In the following travel control device according to claim 1,
Rapid acceleration determination means for determining whether or not rapid acceleration is required after starting;
A distance detecting means for detecting the distance to the right or left turn point,
The start control means determines that a sudden acceleration is required after the start by the sudden acceleration determination means, and if the distance to the right / left turn point detected by the distance detection means exceeds a predetermined distance, the speed change at the start A follow-up travel control device, characterized in that the gear shift position or gear ratio of the machine is a gear ratio corresponding to the first speed position or the first speed. In the following travel control device according to claim 1 or 2,
The left and right turn predicting means predicts a right or left turn according to an operating state of a direction indicator.

Images