JP3750610B2 - Travel speed control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a travel speed control device that controls the travel speed of a host vehicle.
[0002]
[Prior art]
When there is no preceding vehicle, the vehicle travels according to the target traveling speed set by the occupant. When there is a preceding vehicle, the inter-vehicle distance from the preceding vehicle is detected, and the inter-vehicle distance and the vehicle speed are lower than the speed set by the occupant. A travel speed control device that controls the travel speed of the host vehicle in accordance with the relative speed between the vehicle and the preceding vehicle has been proposed. An example of such a traveling speed control device is described in Japanese Patent Application Laid-Open No. 10-151964. When the driver depresses the accelerator pedal during the above-described traveling speed control, the traveling speed control device temporarily stops the control of the traveling speed, and the target driving force according to the amount of depression of the accelerator pedal is achieved. When the driving force of the engine is controlled so that the accelerator pedal is released, the traveling speed control as described above is resumed.
[0003]
[Problems to be solved by the invention]
However, in the conventional travel speed control device, the travel speed control for achieving the target travel speed and the target inter-vehicle distance is not resumed until the accelerator pedal is released, so depending on the amount of depression of the accelerator pedal, Deceleration works. This gives an uncomfortable feeling to the driver who expects acceleration by depressing the accelerator pedal during the travel speed control for achieving the target travel speed and the target inter-vehicle distance.
[0004]
In order to solve the above-mentioned problem, the present invention provides a travel speed control device that can eliminate a sense of incongruity to the driver by preventing the deceleration by the engine brake from acting while the accelerator pedal is depressed. It is intended.
[0005]
[Means for Solving the Problems]
To achieve the above object, run the line speed control device of the present invention, a running speed detecting means for detecting a traveling speed of the vehicle, a target travel speed the running speed of the vehicle detected by said running speed detecting means The target travel speed achievement drive force calculation means for calculating the target travel speed achievement drive force to match the above, an accelerator pedal operation amount detection means for detecting the operation amount of the accelerator pedal by the driver, and the accelerator pedal operation amount detection means An accelerator pedal operation amount corresponding driving force calculating means for calculating an accelerator pedal operation amount corresponding driving force in accordance with the accelerator pedal operation amount detected in step 1, a preceding vehicle detecting means for detecting a preceding vehicle of the host vehicle, and the preceding vehicle The target inter-vehicle distance achievement driving force calculation for calculating the target inter-vehicle distance achievement driving force for making the inter-vehicle distance to the preceding vehicle detected by the detecting means coincide with the target inter-vehicle distance. Means and said when the operation amount of the accelerator pedal detected by the accelerator pedal operation amount detecting means is equal to or greater than a predetermined value, the target speed achieving driving force calculated by the target speed achieving driving force calculating means and said accelerator When the larger one of the accelerator pedal operation amount corresponding driving forces calculated by the pedal operation amount corresponding driving force calculating means is set as the target driving force, and when the preceding vehicle is detected by the preceding vehicle detecting means, Target drive that sets the target inter-vehicle distance achievement drive force calculated by the target inter-vehicle distance achievement drive force calculation means as the target drive force regardless of the target travel speed achievement drive force and the accelerator pedal operation amount corresponding drive force Force setting means, and driving force control means for controlling the driving force so as to coincide with the target driving force set by the target driving force setting means It is an feature.
[0007]
【The invention's effect】
And Thus, according to the run line control device of the present invention, when the operation amount of the accelerator pedal is equal to or greater than a predetermined value, whichever is greater of the target travel speed achieved driving force and the accelerator pedal operation amount corresponding driving force Is set to the target driving force, and the driving force is controlled so as to match the target driving force. Therefore, when the amount of depression of the accelerator pedal is small, the target driving speed achievement driving force is set as the target driving force, and the engine brake The deceleration caused by the vehicle does not act, and the driver feels uncomfortable.
[0008]
Further, when the above line vehicle has been detected, due to a configuration that sets the target inter-vehicle distance achieved driving force to the target driving force, is the driving force corresponding to the operation amount of the accelerator pedal when there is a preceding vehicle is expressed In addition, the host vehicle can be prevented from inadvertently approaching the preceding vehicle.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a system configuration diagram showing an embodiment of a vehicle with a preceding vehicle follow-up travel control device to which the travel speed control device of the present invention is applied. This vehicle is a rear wheel drive vehicle in which the rear wheels 1RL and 1RR are drive wheels and the front wheels 1FL and 1FR are driven wheels, and the driving torque of the engine is transmitted to the rear wheels 1RL and 1RR via an automatic transmission. .
[0010]
The engine rotation state, torque, output and the like can be controlled by the engine control unit 11. Specifically, the engine rotation state, torque, output, etc. can be controlled by adjusting the throttle valve opening, idle valve opening, ignition timing, fuel injection amount, fuel injection timing, etc. The engine torque (driving force) is controlled by controlling the throttle opening by the throttle actuator 21.
[0011]
The automatic transmission can be controlled by a transmission control unit 12. Specifically, by adjusting the working fluid pressure supplied to the clutch and brake in the automatic transmission, it is possible to change the selected gear ratio and obtain the desired reduction ratio.
Each of the wheels 1FL to 1RR includes a wheel cylinder constituting a so-called disc brake. This wheel cylinder applies a braking force to each of the wheels 1FL to 1RR by the supplied braking fluid pressure. The braking force applied to each of the wheels 1FL to 1RR can be controlled by the braking fluid pressure control unit 13. Specifically, for example, by increasing the brake fluid pressure as in the driving force control device (TCS) or reducing the brake fluid pressure as in the anti-skid control device (ABS), The braking fluid pressure can be adjusted to control the braking force applied to the wheels 1FL to 1RR. The braking fluid pressure adjusted in the braking fluid pressure control unit 13 is monitored by a pressure sensor 19.
[0012]
Of course, these control units can be operated independently, but the overall functions are governed by a traveling speed control unit 10 including inter-vehicle distance control and preceding vehicle following traveling control. The traveling speed control unit 10 performs various arithmetic processes to control the traveling speed of the host vehicle, thereby performing inter-vehicle distance control, preceding vehicle following traveling control, and the like.
[0013]
Further, the vehicle includes, for example, a laser radar or the like to detect the presence or absence of a preceding vehicle ahead of the host vehicle or the distance to the preceding vehicle, or an idle switch 17 that is turned on when the engine is idling. Inhibitor switch 18 for detecting the select position of the shift select lever, travel speed sensor 14 for detecting the travel speed of the host vehicle, brake pedal switch 15 for detecting the depression of the brake pedal, and accelerator opening for detecting the depression amount of the accelerator pedal A sensor 20 is provided. Further, this vehicle is provided with a manual switch 9 for setting a target traveling speed of the host vehicle by a manual input by the driver. Further, the vehicle is provided with a display 22 and a speaker 23 for presenting the contents of control by the traveling speed control unit 10 to an occupant, particularly a driver.
[0014]
Next, the calculation process of the traveling speed control performed in the traveling speed control unit 10 will be described with reference to the flowchart of FIG. This calculation process is executed by a timer interrupt every predetermined sampling time ΔT set to, for example, about 10 msec. In this flowchart, no particular communication step is provided, but the results obtained by the arithmetic processing are updated and stored in the storage device as needed, and necessary information and programs are read from the storage device as needed. In addition, the above-described engine control unit 11, transmission control unit 12, and brake fluid pressure control unit 13 communicate with each other at any time, and necessary information and commands are exchanged bidirectionally at any time.
[0015]
In this calculation process, first, in step S1, it is determined from the accelerator opening detected by the accelerator opening sensor 20 whether or not the accelerator pedal is depressed. If the accelerator pedal is not depressed, step S2 is performed. If not, the process proceeds to step S3.
In step S2, it is determined whether or not a preceding vehicle is detected based on a signal from the preceding vehicle detection sensor 16. If a preceding vehicle is detected, the process proceeds to step S4. Proceeds to step S5.
[0016]
In step S5, since no preceding vehicle has been detected, the target engine torque _TE-CMD for achieving the set travel speed set by the manual switch 9 is calculated, and then the process _proceeds to step S6.
In step S4, since the preceding vehicle is detected, for example, the target inter-vehicle distance corresponding to the relative speed between the preceding vehicle and the own vehicle or the traveling speed of the preceding vehicle calculated using the traveling speed of the own vehicle is set. After setting and calculating a target engine torque _TE-CMD for achieving the target inter-vehicle distance, the process _proceeds to step S6.
[0017]
In step S3, the target engine torque TE _-CMD corresponding to the depression of the accelerator pedal is calculated according to the arithmetic processing of FIG. 3 described later, and then the process proceeds to step S6.
In step S6, the target engine torque TE _-CMD calculated in steps S3 to S5 is output to the engine control unit 11, and then the process returns to the main program.
[0018]
Next, the minor program of FIG. 3 performed in step S3 of the arithmetic processing of FIG. 2 will be described.
In this calculation processing, first, in step S31, it is determined whether or not the accelerator pedal depression amount detected by the accelerator opening sensor 20, that is, the accelerator opening is equal to or greater than a predetermined value, and the accelerator opening is determined to be a predetermined value. If so, the process proceeds to step S32. If not, the process proceeds to step S33.
[0019]
In step S33, it is determined whether or not depression of the accelerator pedal is detected by the engine control unit 11, and if depression of the accelerator pedal is detected by the engine control unit 11, the process proceeds to step S32. If not, the process proceeds to step S34.
In the step S32, shifts the accelerator pedal during running speed control is depressed, since the set to "1" to override flag F _OR as a so-called override state to step S35.
[0020]
In the step S34, the process proceeds to the step S35 after resetting the override flag F _OR to "0".
In step S35, it is determined whether or not the idle switch 17 is in an on state. If the idle switch 17 is in an on state, the process proceeds to step S36, and if not, the process proceeds to step S37.
[0021]
In step S36, it is determined whether or not depression of the accelerator pedal is detected by the engine control unit 11. If the depression of the accelerator pedal is not detected by the engine control unit 11, the process proceeds to step S36. If not, the process proceeds to step S38.
In the step S36, the transition from reset the override flag F _OR to "0" in step S39.
[0022]
In the step S38, the process proceeds to the override flag F _OR from set to "1" to the step S39.
In step S39, it is determined whether or not a preceding vehicle is detected based on a signal from the preceding vehicle detection sensor 16. If no preceding vehicle is detected, the process proceeds to step S40. Then, the process proceeds to step S2 of the calculation process of FIG.
[0023]
In the step S40, the override flag F _OR is determined whether the set state of "1", if the override flag F _OR is in the set state, the process proceeds to step S41, otherwise The process proceeds to step S2 of the calculation process of FIG.
In step S41, an accelerator opening corresponding engine torque _TE-ACC corresponding to the accelerator opening detected by the accelerator opening sensor 20 is calculated, and then the process proceeds to step S42.
[0024]
In step S42, the set travel speed attainment engine torque _TE-VSP that achieves the set travel speed set by the manual switch 9 is calculated, and then the process _proceeds to step S43.
In step S43, the larger one of the accelerator opening correspondence engine torque T _E-ACC calculated in step S41 and the set travel speed achievement engine torque T _E-VSP calculated in step S42 is set to the target engine torque. After setting T _{* E / G} T _E-CMD , the process proceeds to step S6 of the arithmetic processing in FIG.
[0025]
According to these calculation processes, when the accelerator pedal is not depressed and no preceding vehicle is detected, the target engine torque T _E-CMD for achieving the set travel speed set by the manual switch 9 is obtained. Is calculated and output to the engine control unit 11. Therefore, the vehicle can travel while maintaining the set travel speed set by the driver. When the accelerator pedal is not depressed and a preceding vehicle is detected, a target inter-vehicle distance is set according to the traveling speed between the host vehicle and the preceding vehicle and the traveling speed of the preceding vehicle. A target engine torque T _{E-CMD to} be achieved is calculated and output to the engine control unit 11. Therefore, it is possible to travel while maintaining an appropriate inter-vehicle distance from the preceding vehicle.
[0026]
On the other hand, when the accelerator pedal is depressed and no preceding vehicle is detected, the engine torque T _E-ACC corresponding to the accelerator position corresponding to the accelerator position and the set travel speed achieving engine torque T that achieves the set travel speed. _The larger of _E-VSP is set to the target engine torque T _E-CMD , which is output toward the engine control unit 11. Therefore, for example, when the accelerator pedal depression is small and deceleration by the engine brake is applied to the accelerator pedal-compatible engine torque T _E-ACC , the set travel speed achievement engine torque T _E-VSP is the final target engine. Torque _{TE-CMD is applied} , and the deceleration caused by the engine brake does not act on the host vehicle, so that the driver feels uncomfortable.
[0027]
On the other hand, even if the accelerator pedal is depressed, if the preceding vehicle is detected, the target engine torque T _E-CMD for achieving the target inter-vehicle distance is directed toward the engine control unit 11 as described above. Therefore, the engine torque corresponding to the depression of the accelerator pedal is not expressed when there is a preceding vehicle, and it is possible to prevent the approaching vehicle from being inadvertently approached.
[0028]
FIG. 4 shows changes in engine torque over time due to the arithmetic processing shown in FIGS. In this timing chart, the driver stepped on the accelerator pedal greatly once at time t ₀₀ and then stepped back slightly at time t ₀₀ with no preceding vehicle from start to finish, then stepped on again after time t ₀₃ and stepped off at time t ₀₅ . . During this time, the set travel speed achievement engine torque _TE-VSP was a constant value. According to the calculation processing of FIG. 3, since the set travel speed achievement engine torque T _E-VSP is larger than the accelerator opening correspondence engine torque T _E-ACC from time t ₀₀ to time t ₀₁ , The set travel speed attainment engine torque T _E-VSP is set to the target engine torque T _E-CMD , and the accelerator opening correspondence engine torque T _E-ACC is greater than the set travel speed attainment engine torque T _E-VSP from time t _01. Therefore, the accelerator opening-corresponding engine torque T _E-ACC is set to the target engine torque T _E-CMD , and the acceleration increases by the amount corresponding to the accelerator opening.
[0029]
However, from further becomes gradually smaller accelerator opening corresponding engine torque T _E-ACC with the back foot accelerator pedal, since from reduced set running speed achieved engine torque T _E-VSP at time t _02, the time t ₀₂ The set travel speed achievement engine torque T _E-VSP is set to the target engine torque T _E-CMD . Therefore, although the acceleration acting on the host vehicle is reduced, the host vehicle does not decelerate because the negative value, that is, the deceleration does not occur. If the accelerator opening correspondence engine torque T _E-ACC is continuously set to the target engine torque T _{E-CMD as} it is, the engine torque becomes a negative value, that is, the engine brake torque acts and the host vehicle is decelerated. It is expected that.
[0030]
Then, when the accelerator pedal is released at time t ₀₅ , the normal set speed attainment engine torque T _E-VSP is set to the target engine torque T _E-CMD and the acceleration corresponding thereto is applied.
On the other hand, FIG. 5 shows that the accelerator opening correspondence engine torque T _E-ACC is set to the target engine torque T _E-CMD as it is. The timing chart, throughout, with no preceding vehicle state, depression driver at time t ₁₀ is temporarily increased accelerator pedal, with gentle back legs, and foot release at time t _12. In this timing chart, as the accelerator pedal is stepped on, the target engine torque T _E-CMD , that is, the accelerator opening-corresponding engine torque T _E-ACC increases and the acceleration also increases. However, when the accelerator pedal is depressed, the target engine The torque T _E-CMD , that is, the accelerator opening corresponding engine torque T _E-ACC also decreases and the acceleration also decreases. When the accelerator pedal is further depressed, the target engine torque T _E-CMD , that is, the accelerator opening correspondence engine torque T _E-ACC becomes a negative value, that is, the engine brake torque, and the deceleration acts on the vehicle. When the driver depresses the accelerator pedal during the traveling speed control, the driver requests acceleration, but actually decelerates, which makes the driver feel uncomfortable. As described above, in the traveling speed control device of the present embodiment, since the deceleration does not act while the accelerator pedal is depressed, it is possible to eliminate such a sense of incongruity for the driver.
[0031]
From the above, the travel speed sensor 14 of FIG. 1 constitutes the travel speed detecting means of the present invention, and similarly, step S5 of the arithmetic process of FIG. 2 and step S42 of the arithmetic process of FIG. 3 achieve the target travel speed. 1 constitutes an accelerator pedal operation amount detection means, step S41 of the arithmetic processing of FIG. 3 constitutes an accelerator pedal operation amount corresponding driving force calculation means, Step S43 of the arithmetic processing in FIG. 3 constitutes a target driving force setting means, the engine control unit 11 in FIG. 1 constitutes a driving force control means, and the preceding vehicle detection sensor 16 in FIG. The step S4 of the arithmetic processing of FIG. 2 constitutes the target inter-vehicle distance achievement driving force calculation means.
[Brief description of the drawings]
FIG. 1 is a vehicle configuration diagram showing an example of a vehicle with preceding vehicle follow-up travel control equipped with a travel speed control device of the present invention.
FIG. 2 is a flowchart showing a calculation process for traveling speed control performed by the traveling speed control unit of FIG. 1;
FIG. 3 is a flowchart showing a minor program executed in the arithmetic processing of FIG. 2;
4 is an explanatory diagram of the operation of the traveling speed control device of FIG. 1; FIG.
FIG. 5 is an explanatory diagram of the operation of a conventional travel speed control device.
[Explanation of symbols]
1FL to 1RR is a wheel 10 is a travel speed control unit 11, an engine control unit 12, a transmission control unit 13, a brake fluid pressure control unit 14, a travel speed sensor 15, a brake pedal switch 16, a preceding vehicle detection sensor 17, an idle switch 18 Inhibitor switch 19, pressure sensor 20, accelerator opening sensor 21, throttle actuator 22, display 23, speaker

Claims (1)

Travel speed detection means for detecting the travel speed of the host vehicle, and target travel speed attainment for calculating a target travel speed achievement driving force for matching the travel speed of the host vehicle detected by the travel speed detection means with the target travel speed. Driving force calculation means, accelerator pedal operation amount detection means for detecting the operation amount of the accelerator pedal by the driver, and accelerator pedal operation amount corresponding drive according to the operation amount of the accelerator pedal detected by the accelerator pedal operation amount detection means A driving force calculating means corresponding to an accelerator pedal operation amount for calculating force, a preceding vehicle detecting means for detecting a preceding vehicle of the host vehicle, and an inter-vehicle distance to the preceding vehicle detected by the preceding vehicle detecting means coincide with the target inter-vehicle distance. a target inter-vehicle distance achieved driving force calculating means for calculating a target inter-vehicle distance achieved driving force for, detected by the accelerator pedal operation amount detecting means The accelerator pedal operation calculated by the target travel speed achievement driving force calculated by the target travel speed achievement driving force calculating means and the accelerator pedal operation amount corresponding driving force calculating means when the operation amount of the accelerator pedal is equal to or greater than a predetermined value. The larger driving amount corresponding to the amount is set as the target driving force, and when the preceding vehicle is detected by the preceding vehicle detecting means, the target traveling speed achievement driving force and the accelerator pedal operation amount corresponding driving force are detected. The target driving force setting means for setting the target inter-vehicle distance achievement driving force calculated by the target inter-vehicle distance achievement driving force calculation means as the target driving force, and the target driving force setting means. A driving speed control device comprising driving force control means for controlling the driving force so as to coincide with the target driving force.

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