JPH03118699A - Travel controller for moving vehicle - Google Patents

Abstract

PURPOSE:To obtain a travel controller for a moving vehicle so as to secure safety during curve travel and acceleration after the vehicle goes out from the curve by calculating delay time to the traveling vehicle itself and simulating the speed of a preceding vehicle while being delayed only for the delay time. CONSTITUTION:In a moving vehicle 10, a distance sensor 1 is provided to measure a distance L to the preceding vehicle and a vehicle speed sensor 2 is provided to detect the speed of the vehicle itself. When following-up travel is executed, it is executed with the operation of a switch 9 by a driver. However, whether the following-up travel is executed or not is finally determined by a following-up travel determination part 8 while considering a distance L and a vehicle speed V, etc. In a preceding vehicle speed calculation part 3, a speed (v) of the preceding vehicle is calculated based on the change of the distance L and the speed V, and delay time DELTAt(=L/V) of the vehicle to the preceding vehicle is calculated as well. In a target speed calculation part 4, the vehicle speed (v) is stored and the speed (v) delayed only by the DELTAt is set as a target speed VT of the vehicle itself. A throttle 6 is controlled based on the current vehicle speed V and the vehicle speed VT. Thus, the same pattern as the preceding vehicle is realized and the delay is only DELTAt.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a travel control device for a mobile vehicle that follows a preceding vehicle, and more specifically, a mobile vehicle that controls movement to follow the speed of a preceding vehicle. This invention relates to a vehicle travel control device.

(Prior Art) Generally, as a conventional technology for following driving, a control technology is known that controls driving so as to maintain a constant distance between the vehicle and the preceding vehicle. Furthermore, there is also a method, as disclosed in Japanese Patent Laid-Open No. 61-6031, in which the set inter-vehicle distance to the preceding vehicle is set as a function of the vehicle's own speed or relative speed.

(Problem to be Solved by the Invention) In other words, in such conventional technology, the distance between vehicles is set with the main focus on braking distance, and no attention is paid to follow-up driving in response to changes in the driving environment. do not have. for example,
Consider the case where the vehicle enters a curve.

In the conventional technology where the inter-vehicle distance is constant, when the leading vehicle enters a curve, the leading vehicle decelerates. The vehicle then decelerates to maintain a constant distance between vehicles. When the leading vehicle accelerates after exiting the curve, your own vehicle will also accelerate, but since this acceleration occurs after the preceding vehicle by the above-mentioned inter-vehicle distance, your vehicle may Depending on the situation, there is a high possibility that this will occur when entering a curve.

For this reason, acceleration is performed in the curve section, reducing ride comfort and safety.

In follow-up control such as that disclosed in Japanese Patent Application Laid-Open No. 61-6031, the opposite problem occurs. That is, in this Japanese Patent Application Laid-Open No. 61-6031, when the preceding vehicle enters a curve and decelerates, the relative speed difference increases in the negative direction, so the set inter-vehicle distance also decreases. Due to this reduction in the set inter-vehicle distance, the own vehicle is allowed not to reduce its speed, and in some cases, it may enter a curve without decelerating at all. Furthermore, when the preceding vehicle accelerates after passing the curve, the relative speed difference increases in the positive direction, so the set inter-vehicle distance also increases. It is okay to be late.

The present invention was proposed in order to solve the problems of the prior art, and its purpose is to propose a travel control device for a moving vehicle that ensures safety while traveling on a curve and acceleration when exiting a curve. It is something to do.

(Means and operations for achieving the object) As shown in FIG. speed storage means for detecting and storing the speed of the vehicle; means for calculating the delay time of the own vehicle relative to the preceding vehicle based on the inter-vehicle distance and the own speed; The present invention is characterized by comprising a target speed setting means for setting the preceding vehicle's speed in the past as a target speed of the own vehicle, and a travel control means for controlling the travel of the own vehicle with this target speed as a target.

That is, the own vehicle simulates the vehicle speed of the preceding vehicle with a delay of the above-mentioned delay time.

(Embodiments) Hereinafter, preferred embodiments to which the present invention is applied will be described with reference to the accompanying drawings.

FIG. 2 is a block diagram of the travel control device for the mobile vehicle 10 of this embodiment. The moving vehicle 10 includes a distance sensor 1 that measures the distance between the vehicle and the preceding vehicle 1, a vehicle speed sensor 2 that detects the own vehicle speed V, and a throttle 6 and brakes that perform acceleration and deceleration based on predetermined control. It has 7. Whether or not to perform follow-up travel can be controlled by operating a switch 9 by the driver. However, whether or not follow-up travel is ultimately performed is determined by the determination unit 8, taking into consideration the following distance, the own vehicle speed V, and the like.

The preceding vehicle speed calculating section 3 calculates the speed V of the preceding vehicle based on the change in the inter-vehicle distance and the own vehicle speed (2). At the same time, the delay time Δt of the own army relative to the preceding vehicle is also calculated.

The target speed calculation unit 4 stores the vehicle speed V of the preceding vehicle in a memory (not shown). Further, the target speed setting unit 4 sets the speed V of the preceding vehicle in the past, which was delayed by the above-mentioned Δt, as the target vehicle speed ■A of the own vehicle. Then, the throttle 6 (and the brake 7, if necessary) is controlled based on the current vehicle speed (2) of the own vehicle and this target vehicle speed v7. In this way, as shown in FIG. 3, the own vehicle follows the speed of the preceding vehicle, that is, the same driving pattern as the preceding vehicle is realized.
The delay is only Δt.

FIG. 4 is a diagram plotting changes in the positions of the preceding vehicle and the own vehicle along the time axis when the vehicle is entering a curve. In the figure, curve A shows the change in the position of the preceding vehicle, and curve B shows the change in the position of the own vehicle. For comparison, C shows the change in the position of the own vehicle when the conventional control technology is used when the inter-vehicle distance is constant. The slope of these curves indicates vehicle speed. In curve C under conventional control, it can be seen that the vehicle speed of the own vehicle is high while traveling on a curve. On the other hand, in the curve B controlled by the present embodiment, the target vehicle speed is delayed by Δt with respect to the vehicle speed V of the preceding vehicle, so the curve section has the lowest vehicle speed. It also accelerates appropriately when exiting curves. This ensures driving stability and comfort.

FIG. 5 shows a flowchart of the control procedure in the fifth embodiment. FIG. 5A shows a routine for storing the vehicle speed of the preceding vehicle, which is executed periodically, and corresponds to the preceding vehicle speed calculation section 3. That is, in step S2, the distance measurement signal and the own vehicle speed V are input, and in step S4, the distance between the two vehicles to the preceding vehicle is calculated based on this distance measurement signal. In step S6, the vehicle speed V of the preceding vehicle is calculated from the change in L and the own vehicle speed V.

That is, In step S10, v (t) and L (t) are stored in the memory using the current time t as an index.

FIG. 5B shows the follow-up travel determination section 8. 5 is a flowchart showing a control procedure in the target speed calculation section 4. FIG. That is, in step SL2, the current time t is known, and in step S14
Now, read the own vehicle speed ■ from the sensor. Furthermore, in step S16, the inter-vehicle distance L (
t). In step S18, the delay time Δt is calculated based on equation (1). In step S20, the set state of the mode setting switch 9 is checked, and if it is off, the process proceeds to step 338 and subsequent steps to perform normal driving control based on the driver's accelerator operation.

If the mode switch is on, it is determined whether the distance between vehicles has reached an appropriate speed for following the vehicle. This is an appropriate speed. Then, in consideration of the measurement error, when L-Lol<α (α: small value), the follow-up travel mode is set in step S24. Then, in step S26, the speed v (t - Δt) of the preceding vehicle past the time Δ is set as the target vehicle speed vT of the own vehicle from the memory. Then, in step 328, the difference between the target vehicle speed VT and the current vehicle speed is output to the throttle 6 to perform acceleration/deceleration. In this case, in the example shown in Figure 4, if the following mode had already been set by the time the preceding vehicle entered the curve, the own vehicle would not be able to follow the preceding vehicle until it entered the curve and decelerated. Since the target speed is set to v (-Δt), even if the preceding vehicle enters the curve and decelerates, the own army will not decelerate.

After that, if the inter-vehicle distance is maintained at l L-L, l < α, step 826. In step S28, the own army performs speed follow-up control using v(t-Δt) of the preceding vehicle as a target speed.

If it is determined in step S22 that lLL-L, I≧α, the process advances to step S30 to check whether L>L+. During this time, the value L1 is L as shown in FIG.

is set to a value greater than . If this step S
If the determination in step S30 is YES, it is determined that the inter-vehicle distance is too wide for follow-up travel, and the follow-up mode is reset in step S28.

If it is determined in step S30 that the inter-vehicle distance is not large enough to cancel the following driving, step S30
Proceed to step 32 and check whether the following distance is getting too close to less than L2. During this time, the value 2 is set to a value smaller than Lo, as shown in FIG. If it is determined that the vehicle has come too close, the process proceeds to step S36 to decelerate, and the tracking mode is reset in step 838.

If the inter-vehicle distance is L2≦L≦L, the control goes to step S.
30→Step 532→Step S34. In step S34, the set state of the follow-up mode is checked. If this mode has not been set, the routine proceeds to step 338 and subsequent steps and normal driving is continued. Conversely, if this mode is set, vehicle speed follow-up control is continued from step 326 onwards. That is, once the following mode is set in step S24, the following mode will not be canceled as long as the inter-vehicle distance is within the range of L2≦L≦Ll. Such hysteresis control prevents frequent setting/resetting of the tracking mode and ensures smooth operation.

Returning to FIG. 4, consider the case where the vehicle's own weight increases into a curve while following the vehicle in front with the following distance. If the preceding vehicle enters the curve at a constant speed 'V+, the own vehicle also attempts to enter the curve at a constant speed, delayed by Δt. Under this assumption, if the preceding vehicle starts decelerating (v2) at time t, as shown in FIG. 4, the host vehicle maintains a constant speed VT:Vl by Δt. That is, after time Δ, the own army travels a distance of Δt−v+(=L) and reaches the entrance point of the curve. At this time, △1 (
=1++Δt) has elapsed.

Then, the own vehicle has the target vehicle speed Vr ” V
(t + + △ - △t) = v (t) = v+ is set. That is, at the time of entering a curve, the approaching speed of the preceding vehicle is simulated.

Even if the preceding vehicle changes its speed in various ways before entering the curve, the calculation of Δt in step S18 is repeated in a short cycle, so when the own vehicle approaches the curve,
You will definitely have to slow down in the same way as the vehicle in front. Also,
This speed follow-up control is maintained throughout the curve section, so as long as the vehicle in front maintains a suitable driving direction for the curve, the own vehicle will also be simulated, ensuring safety and comfort. In this respect, the control of this embodiment has a significant feature compared to the conventional control in which the inter-vehicle distance is constant. In addition, in this embodiment, as described above, the setting of △t is calculated based on the own vehicle speed of the inter-vehicle distance at the point of entering a curve and the point of exiting a curve, and the setting of △t is calculated according to the speed of the vehicle in front in the past by this △t. This eliminates the disadvantages of the above-mentioned Japanese Patent Laid-Open No. 61-6031, such as dangerous driving when entering a curve and delays in acceleration when exiting a curve.

The present invention can be modified in various ways without departing from its spirit. For example, the mobile vehicle may be a motor-controlled vehicle.

(Effects of the Invention) As explained above, according to the driving control device of the present invention, the driving speed of the preceding vehicle is simulated, so as long as the preceding vehicle maintains proper driving, the driving of the own vehicle is controlled. Properly maintained. In particular, the delay time during simulation is calculated based on the inter-vehicle distance and the own vehicle speed. For this reason, when there is a close relationship between the shape of the road and vehicle speed, such as when driving around a curve, it is possible for the military to drive in a way that matches the shape of the road with the vehicle in front. Since the simulation is performed in accordance with the shape of the vehicle, it is possible to perform driving that matches the road conditions, that is, safe and comfortable driving.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of the present invention, Fig. 2 is a block diagram showing the configuration of the embodiment, and Fig. 3 is a block diagram showing the configuration of the embodiment.
Figure 4 is a diagram conceptually explaining the control of the embodiment shown in Figure 2. Figure 4 is a diagram specifically explaining the control of the embodiment shown in Figure 2, taking curve driving as an example. Figures 5A and 5B are diagrams showing the embodiment. FIG. 6 is a flowchart showing the control procedure related to the following. FIG. 6 is a diagram illustrating the setting conditions of the follow-up mode in this embodiment. In the figure, 1... distance measurement sensor, 2... vehicle speed sensor, 3... preceding vehicle vehicle speed calculation section, 4... target speed calculation section, 5... own vehicle speed control section, 6...・Throttle, 7...Brake, 8...Following travel determining section, 9...Mode setting switch.

Claims (1)

[Claims] (1) A detection means for detecting the distance between vehicles in front and the speed of the vehicle in front; a speed storage means for detecting and storing the speed of the vehicle in front; Calculating means for calculating the delay time with respect to the vehicle, and calculating the past speed of the preceding vehicle by the amount of the delay time out of the stored speed of the preceding vehicle,
1. A travel control device for a mobile vehicle, comprising: a target speed setting means for setting a target speed of the own vehicle; and a travel control means for controlling the travel of the own vehicle using the target speed as a target.