JPS5865944A - Constant speed travelling system for automobile - Google Patents

Abstract

PURPOSE:To decelerate an automobile by receiving steering angle information from a steering angle sensor in auto-drive mode to reduce a set vahicle speed in proportion to the steering angle and steering angular velocity. CONSTITUTION:When an automobile is transferred from the normal travelling condition to the auto-drive one, a set switch 6 is turned from an to off to carry out the auto-drive control. In a system to calculate control signal value of an actuator 2 by at least set vehicle speed data and present vehicle speed data in the auto-drive mode for constant travelling of the automobile, a calculating means receives information of a sensor 4 generating steering angle information proportional to steering angle to reduce the set vehicle speed in proportion to the steering angle and steering angular velocity for decelerating the automobile. Further, after the deceleration, the automobile can be automatically returned to the set vehicle speed.

Description

[Detailed Description of the Invention] The present invention is a constant speed driving system for automobiles, and in particular, it is possible to realize safe driving by reducing the set vehicle speed in proportion to the degree of curvature of the road curve and the driving speed during automatic driving (1). This invention relates to a constant speed driving system for automobiles.

In general, constant speed driving systems for automobiles set the value of the control signal to be supplied to the throttle actuator, for example, the duty ratio of the control pulse, in the auto drive mode, that is, the constant speed driving mode set by the driver, depending on the set vehicle speed and the current vehicle speed. A configuration is adopted in which the vehicle is driven at a constant speed at the set vehicle speed.

Incidentally, the auto drive mode is generally selected while driving on a highway, and is suitable for reducing the driver's burden and effort. However, while expressways generally have straight sections for the most part, they also have a relatively large number of curved sections, so vehicles often enter curves in cent drive mode.

In such a case, since automatic driving around the curve is dangerous, the driver usually decelerates the vehicle by depressing the brake pedal or the like. For this reason, auto drive will not be canceled automatically, and if you want to drive at a constant In'r speed again at the set vehicle speed before cancellation after passing a curve, you can perform a new resume operation to return to the set vehicle speed. I had to be strong.

The present invention has been made in view of the above points, and provides a constant speed driving system for automobiles that does not require canceling the auto drive mode even when the vehicle enters a curve from a straight line, and can realize safe driving. The purpose is to Therefore, the present invention provides a constant speed driving system for automobiles that calculates the value of an actuator control signal based on at least set vehicle speed data and current vehicle speed data in auto drive mode to drive the vehicle at a constant speed, which is proportional to the steering angle. A steering angle sensor for outputting steering angle information and a calculation means are provided, and the operating means receives the steering angle information from the steering angle sensor during auto drive mode;
The present invention is characterized in that it is configured to reduce the set vehicle speed in proportion to the steering angle and steering angular velocity to decelerate the vehicle.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of a constant speed traveling system for an automobile according to the present invention.

In FIG. 1, 1 is a constant speed cruise control device, 2 is an actuator which is driven by a drive signal from the constant speed cruise control device w1 and adjusts the opening of a throttle valve (not shown), and 3 is a main switch (not shown). 4 is a steering angle sensor that outputs steering angle information, such as an analog voltage signal, proportional to the steering angle of the steering wheel; 5 is a vehicle speed sensor, which is installed on the output shaft of the transmission (not shown), and outputs a pulse signal with a half-wave number proportional to the vehicle speed; 6 is a cent switch; when turned on, the auto drive mode is set to constant speed. 7 is a resume switch that instructs the driving control device 1, and is mainly turned on when driving at a constant speed at the original set speed after the automatic drive mode has been canceled. 8 is a cancel switch, which consists of a clutch switch (for manual cars), a neutral switch (for AT]i), a stop lamp switch, a parking brake switch, etc., and is used to cancel the auto drive mode. respectively.

In the freezing constant speed traveling control device, 9 is a microcomputer which is the calculating means according to the present invention, 10 is a constant voltage circuit,
11 is a crystal oscillator, 12 is a reset circuit, 13 is an analog/digital converter that converts an analog voltage signal into digital information, that is, steering angle digital information, 14 is an input cover sofa, and 15 and 16 are output buffers, respectively. It represents.

Further, in the actuator 2, reference numeral 17 represents a control pulp for adjusting the negative pressure in a diaphragm chamber (not shown), and reference numeral 18 represents an IJ subarp that is maintained in a closed state during the auto drive mode.

When the main switch 3 is turned on, a constant voltage is applied to the microcomputer by the constant voltage/voltage circuit 10, and the microcomputer is reset by the reset circuit 12 to start processing and synchronize with the clock signal from the crystal oscillator 11. second
A series of processes as shown in the flowchart in the figure are executed. First, the basic processing operation of each step in FIG. 2 will be explained.

In FIG. 2, 101 is a C in the microcomputer.
It represents the steps for initializing the various registers of the PU, the memory contents of the RAM, etc.

Reference numeral 102 represents a step of calculating the vehicle speed based on the vehicle speed information from the vehicle speed sensor 5.

Reference numeral 103 represents a step of determining whether or not the auto drive mode is selected based on each input signal from the set switch 6, resume switch 7, and cancel switch 8.

104 is a step of checking the θ change flag and determining whether or not a steering angle of 0 should be calculated.

Note that this θ change flag is set to "1" at approximately 10m8 cycles in a timer interrupt routine shown in FIG. 3, which will be described later.

105 represents a step for resetting the θ change flag to "0".

Reference numeral 106 represents a step of calculating the absolute value θB of the difference between the reference steering angle, that is, the steering angle O8 when the steering wheel is at the center position of the movable range, and the steering angle OA. For example, the steering angle at the left turning end of the steering wheel is expressed in hexadecimal notation as [00j
In addition, the steering angle at the right turning end is similarly expressed as IF Fj, and the corner steering reference angle O8 is expressed as "7F". Therefore, as shown in Fig. 4, for example, when the steering wheel is at the illustrated position P, the steering reference turning angle O8, the current steering turning angle OA, and the absolute value OB are respectively It will look like the one shown. Further, when the knob position is to the left of the center position, the relative value θB is the same.

107 is the absolute value θB calculated in step 106 above.
, P) [dead zone area defined at a certain angle (
The difference between the angle θ0 (the shaded area shown in Figure 4), or the correction angle θC
represents the step to calculate .

108 is the correction angle Oc calculated in step 107 above.
represents a step of determining whether or not is a positive value. In other words, this step 108 is a step for determining whether the handle position is outside the dead zone area.

Reference numeral 109 represents a step of forcibly setting the correction angle θC to "0" when the determination result of step 108 is rNOJ.

110 is the correction angle θC calculated through steps 106, 107 and 108 above or step 106.10 above.
7. The absolute value of the difference between the correction angle θC set to "0" through steps 108 and 109 and the correction angle θC-1 calculated in the previous θ calculation is approximately 1 (result of dividing by the time width Δt of 1 ms) , that is, the steering angular velocity θD.

111 is the correction angle θC calculated as above and step 1
10 represents the step of calculating the changed set vehicle speed SOC based on the steering angular velocity θD calculated in step 10 and the set vehicle speed So. That is, this step 111 changes the set vehicle speed SOC to Soc = S□ -K, lθcl K2O
.

Calculate using the calculation formula. Here, 1 and 2 in the above formula are constants.

112 is a step for performing auto drive control (constant speed driving control). That is, this step 112 calculates the changed set vehicle speed SOC, the current vehicle speed S calculated in step 102 in the current program execution, and the previous vehicle speed S- calculated in step 102 in the previous program execution.
1. A predetermined calculation formula, namely D=DO+G(SO
C-(S0K(S-8-1)/Δ1)) is calculated to determine the date D of the control pulse to be supplied to the control valve 17. At the same time as the trench, maintain the 9IJ-subvalve ■8 in the closed state. In this equation, Do represents the initial duty determined according to the set vehicle speed So, G represents the bias gain coefficient, and Δt represents the time width for determining the acceleration.

Next, the processing operations of the entire flowchart shown in FIG. 2 can be roughly divided into (a) when the car is in a normal driving state, and (b) when the normal car driving state has transitioned to the autodrive state and is in the autodrive state. explain.

(a) When the vehicle is in normal driving condition.

In this driving state, the set switch 6 has not been turned on yet, so only the closed loop consisting of rNOJ and Hikoshi, steps 102 and 103 is repeatedly executed as the determination result of step 103, and the θ calculation and auto drive control are not performed together.

(b) When the vehicle transitions from a normal vehicle running state to an auto drive state and is in the auto drive state.

When the centrifuge switch 6 is turned from on to off under normal vehicle running conditions, the determination result in step]03 is reversed to rYEsl, and step 104 is then executed.

If the θ change flag is reset to "o" at this point, the determination result in step 104 is rNOJ
Then, in step 112, automatic drive control is performed. That is, the peeping vehicle speed S calculated in step 102 is set as the set vehicle speed SO, and the above formula D = Do + G (Soc (S
+K(S-8-+)/Δt)] and outputs a control pulse signal having the duty ratio to the output cover sofa 15. Note that at this point, the changed set vehicle speed SOC has not been calculated yet, so the SOC in the above equation is slightly converted to the set vehicle speed So.

Then, by executing the timer interrupt routine shown in Figure 3, θ is
When the change flag is set to "1", the determination result in step 104 is reversed to rYEsJ.

In the timer interrupt routine shown in FIG. 3, 201 represents a step for saving registers.

202 represents a step of incrementing the RAM for the reference timer and also incrementing the RAM for counting the number of timer interrupts.

203 represents a step of determining whether or not the value of the RAM for counting the number of timer interrupts matches "6".

204 is A/ from the analog/digital converter 13.
This represents the step of reading the D value, that is, the steering angle digital information.

205 represents a step of setting the θ change flag to “1” and permitting θ calculation.

Reference numeral 206 represents a step in which the t value read in step 204 is set as the current steering angle OA and is used as a parameter in step 110 shown in FIG.

207 represents the step of starting the analog/digital converter 13.

208 represents a step of resetting the value of the RAM for counting the number of timer interrupts to "0".

209 represents a step of restoring the register saved in step 201 above.

This timer interrupt routine is executed at a cycle of, for example, 1.7 ms, and step 204.20 is executed at a cycle of approximately 10 m5.
5.206.207 and 208 are executed sequentially.

As mentioned above, when the determination result at step 104 shown in FIG. to calculate the correction angle 0c, and in step 108 it is determined whether or not the correction angle Oc has a positive value.If the determination result is "YES", the process directly proceeds to step 110; If is rNOJ, the complementary angle Oc is forcibly set to "0" in step 109, and the process proceeds to step 110.
In step 110, the steering angular velocity θD is calculated from the correction angle θC and the previous correction angle 0c-1 set in step 206 shown in FIG. The changed set vehicle speed SOC is calculated based on the corrected angle Oc and the steering angular velocity θD calculated in step 110, and in step 112, the changed set vehicle speed Soc and the current value calculated in step 102 are calculated. The duty D is calculated based on the vehicle speed S and the previous current vehicle speed S-1. Thereafter, each time the determination result of step 104 reaches rYEsJ, the calculation of the changed set vehicle speed SOC is performed, and the changed set vehicle speed SOC is calculated.
The data D corresponding to is calculated. Note that step 1
If the determination result of step 04 is rNOJ, the changed set vehicle speed Soc is not calculated, and the date D corresponding to the immediately previous changed set vehicle speed SOC is calculated in step 112.

After that, when a cancel instruction signal is input from the cancel switch 8, the determination result in step 103 becomes "NO" again, and the θ calculation and auto drive control are no longer performed, and steps 102 and 103 are repeated. executed.

In this way, the microcomputer 9 performs the O operation in the auto drive mode and also calculates the data D based on the changed set vehicle speed SOC calculated by the O operation. Since the change setting vehicle speed SOC is given by the above formula, that is, Soc = SQ K + lθc l - K2θD, the more the correction angle Oc of the current steering angle 9 angle OA is dogged, and the larger the steering angular velocity θD is. The greater the value, the smaller the value of the changed set vehicle speed SOC, and the greater the degree of decrease in vehicle speed.

As explained above, the present invention provides a constant speed driving system for an automobile in which the value of an actuator control signal is calculated based on at least set vehicle speed data and current vehicle speed data in an auto drive mode to drive the vehicle at a constant speed. A steering angle sensor outputting steering angle information proportional to the angle i~ and a calculation means are provided,
The calculation means is configured to receive steering angle information from the steering angle sensor during the auto drive mode, and to reduce the set vehicle speed in proportion to the steering angle and steering angular velocity to decelerate the vehicle. Therefore, even if the car enters a curve while in autodrive mode, it is possible to decelerate the car according to the curve degree and angular velocity without canceling autodrive mode, and automatically return to the set vehicle speed after deceleration. As a result, safe driving can be maintained, and there is no need to perform a resume operation, which is normally performed after cancellation, and the burden on the driver can be reduced.

In the above embodiment, the analog/digital converter 13 is provided outside the microcomputer 9, but the analog/digital conversion may be performed by the microcomputer 9.

[Brief explanation of drawings]

FIG. 1 shows the configuration of an embodiment of a constant speed driving system for automobiles according to the present invention, FIGS. 2 and 3 are flowcharts for explaining the processing operations thereof, and FIG. 4 is a conceptual diagram for explaining the present invention. The figures are shown respectively. O ■...Constant speed traveling control device 2... Actuator 4... Steering angle sensor 5... eVehicle speed sensor 1 Figure 2

Claims (1)

[Claims] Steering angle information proportional to the steering angle in an automotive constant speed driving system that calculates the value of an actuator control signal based on at least set vehicle speed data and current vehicle speed data to drive the vehicle at a constant speed in auto drive mode. The calculation means receives and receives steering angle information from the steering angle sensor during auto drive mode, and calculates the above settings in proportion to the steering angle and steering angular velocity. A constant speed driving system for an automobile, characterized in that it is configured to reduce vehicle speed and decelerate the automobile.