JP4270424B2 - Speed display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speed display device, and more particularly, to a speed display device suitable for guiding an appropriate speed of a motorcycle traveling on a curved road to a driver or reducing the speed to an appropriate speed.
[0002]
[Prior art]
There is known a control method for issuing a warning to a driver (rider) when a vehicle is driven exceeding an appropriate speed for smoothly traveling on a curved road (hereinafter simply referred to as “curve”). For example, in the control method described in Japanese Patent Laid-Open No. 8-72640, the distance to the guardrail provided on the curve is detected by an optical sensor, the radius of the curve is calculated based on the detection result, and the vehicle An alarm is issued if the running speed exceeds the speed at which this curve can be smoothly run.
[0003]
[Problems to be solved by the invention]
The above control method is suitable as a speed display device for a four-wheeled vehicle, but is not always satisfactory when applied to a motorcycle. In a motorcycle, the vehicle body runs on a curve with the vehicle body tilted (banked). Therefore, the bank angle must be taken into account in order to guide the appropriate speed to the rider while driving on a curve. This is because there is an appropriate speed corresponding to the bank angle even when traveling on a curve having the same curvature. However, conventionally, a method for notifying or controlling the appropriate traveling speed of the curve in consideration of the bank angle has not been adopted.
[0004]
An object of the present invention is to solve the above-mentioned problems and to provide a speed display device capable of guiding a turning speed suitable for a motorcycle for traveling on a curve to a rider or automatically limiting the speed. And
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a curve detection means for detecting the magnitude of a curve encountered, a vehicle speed detection means for detecting the current speed of the vehicle, and a vehicle running on the curve at a first bank angle at which the vehicle body contacts the ground. A comparing means for comparing a second turning speed at which the vehicle can travel the curve at a first turning speed and a second bank angle smaller than the first bank angle, and a current speed detected by the vehicle speed detecting means; There is a first feature in that it includes control means for notifying the driver based on the comparison result. In addition, there is a second feature in that the present invention further comprises display means for performing an overspeed display when the current speed exceeds the first turning speed or the second turning speed.
[0006]
In addition, the present invention has a third feature in that when the current speed exceeds the second turning speed, an amount of excess speed with respect to the second turning speed is displayed on the display means. A fourth feature is that a speed limiting means for converging the speed of the vehicle toward the first turning speed when the current speed exceeds the first turning speed is provided.
[0007]
According to the above feature, when the current vehicle speed exceeds an appropriate turning speed corresponding to the size of the curve, that is, the curvature or the radius, the overspeed display is performed. In particular, according to the third feature, the excess speed is indicated, and further according to the fourth feature, the vehicle speed is limited to a speed at which the vehicle can travel under the first bank angle.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the main functions of the speed display device of the present invention. A microcomputer is used for the speed display device. In the figure, an irradiation unit 30 emits laser light at a plurality of irradiation angles, and a light receiving unit 31 receives the laser light. The distance calculation unit 32 calculates the distance of the reflecting object based on the timing of irradiation and light reception. The curve detection unit 33 detects that the object reflecting the laser beam indicates a road curve based on the plurality of distance data obtained by the distance calculation unit 32 and calculates the radius R of the curve. Since the curve detection unit 33 is provided for recognizing the size of the curve, the curve detection unit 33 may calculate the curvature of the curve without being limited to the radius of the curve. For example, when a guardrail is installed on a curve, the radius or curvature is calculated. The curve detection unit 33 measures the distance between the host vehicle and the obstacle based on the control device described in the above-mentioned JP-A-8-72640, that is, the reflected light of the light irradiated in a plurality of planned directions. This can be realized by a control device that recognizes that the obstacle is a guard rail based on the above. However, the present invention is not limited to this, and the presence / absence of a guardrail and the radius of a curve may be detected by image determination using an image recognition apparatus using a known imaging unit such as a CCD camera.
[0009]
The vehicle speed detector 34 detects the current traveling speed of the host vehicle. The speed table 35 stores a speed suitable for traveling the curve radius for each bank angle. Details of these speeds and bank angles will be described later. When the curve radius is input, the speed table 35 outputs a speed corresponding to the curve radius. The state determination unit 36 compares the speed input from the speed table 35 with the current vehicle speed, and determines which of the planned conditions the current traveling state of the host vehicle corresponds to.
[0010]
If the state determination unit 36 determines that the current vehicle speed exceeds the speed suitable for traveling on the curve based on the determination result, the state determination unit 36 causes the display unit 26 to display a warning that the speed is exceeded. An instruction is output and a speed reduction instruction is output to the speed limiter 37. The speed limiting unit 37 is formed by any one of a fuel injection amount adjusting unit, an ignition timing adjusting unit, a brake adjusting unit, or any combination thereof. Note that only one of the display unit 26 and the speed limiting unit 37 may be energized.
[0011]
Next, the operation of the speed display device configured as described above will be described. FIG. 2 is a flowchart showing the operation of the speed display device. In step S1, it is determined whether or not the curve has been recognized, that is, whether or not the vehicle has reached a position where the curve can be recognized. If the curve is recognized, the process proceeds to step S2, and the radius R of the curve recognized in step S1 is calculated. These determinations and calculations are performed by the curve detection unit 33.
[0012]
In step S3, a turnable speed (limit speed) V _LMT is calculated based on the primary ground bank angle. Here, the primary contact bank angle is an individual characteristic value of a motorcycle, and when the bank angle is increased while increasing the speed in traveling along a circle of a predetermined radius in single-seat driving. The bank angle at which a part of the vehicle body excluding the tire is in contact with the ground (hereinafter referred to as “first bank angle”).
[0013]
In step S4, an appropriate turning speed V _STD is calculated. The appropriate turning speed V _{ST D} is a turnable speed at a bank angle scheduled to be smaller than the first bank angle (hereinafter referred to as “second bank angle”). The second bank angle is set in advance between 70% and 90% of the first bank angle, for example.
[0014]
The relationship between the bank angle and the vehicle speed when traveling on a curve with a given radius is determined in advance through experiments and trial calculations. Based on the relationship, the vehicle speed and the radius for each of the first bank angle and the second bank angle are determined. The correspondence is stored in the speed table 35. In steps S3 and S4, vehicle speeds (limit speed V _LMT and appropriate turning speed V _STD ) corresponding to the radius R calculated in step S2 are obtained.
[0015]
In step S5, the vehicle speed is detected. A well-known sensor can be used for detecting the vehicle speed. The following determination is made based on the detected vehicle speed. First, in step S6, it is determined whether or not the vehicle speed is equal to or less than the appropriate turning speed _STD . If this determination is affirmative, step S7 to step S14 are skipped, and the process of this flowchart ends.
[0016]
On the other hand, when the vehicle speed is was properly turning speed _STD above, the process proceeds to step S7, between the vehicle speed is appropriate turning speed _STD and limit velocity _LMT near the predetermined value (limit speed _LMT-.alpha. (alpha margin)) Judge whether there is. If this determination is affirmative, the process proceeds to step S8, and the difference between the current vehicle speed and the appropriate turning speed _STD is calculated. In step S9, an overspeed display is performed. For example, based on the calculation result of step S8, the display unit 26 performs display for guiding the overspeed, such as “20 km / h over!”.
[0017]
Proceeds to step S10 if the determination is negative in step S7, it is determined whether the vehicle speed has exceeded a predetermined value of the limit speed _LMT near the (limit speed _{LMT-.alpha.).} If this determination is affirmative, the process proceeds to step S11, and the difference between the current vehicle speed and the appropriate turning speed _STD is calculated. In step S12, the overspeed display similar to step S9 is performed. In step S13, PID (proportional integral derivative) control for limiting the vehicle speed to the limit speed _LMT or less is performed. Target speed for the PID control is a predetermined value of the limit speed _LMT vicinity (limit speed _{LMT-.alpha.).}
[0018]
In step S14, at least one of fuel supply adjustment, ignition timing adjustment, and brake adjustment is performed based on the PID control result.
[0019]
FIG. 3 is a diagram showing the relationship between the speed reduction coefficient _KFI for determining the fuel injection amount for fuel supply adjustment and the PID calculation value. The speed reduction coefficient _KFI has a maximum value of “1.0” and is set so as to decrease as the PID calculation value increases. However, the minimum value is “0.5”. The fuel injection amount is corrected by multiplying the fuel injection amount calculated by a known calculation method by this speed reduction coefficient _KFI . That is, the fuel injection amount is reduced.
[0020]
FIG. 4 is a diagram showing the relationship between the retard amount for determining the ignition timing delay amount (retard amount) for adjusting the ignition timing and the PID calculation value. The retard amount is set to increase as the PID calculation value increases. However, the retard amount at which the ignition timing becomes top dead center is set to the maximum value. The ignition timing is a timing obtained by delaying the amount of retard obtained by the map of FIG. 4 from the ignition timing obtained by the standard map.
[0021]
FIG. 5 is a system block diagram showing the configuration of hardware for fuel injection control as fuel supply adjustment and ignition timing adjustment. The ECU 1 for performing fuel injection control and ignition timing adjustment includes a microcomputer, and according to a predetermined algorithm, an intake air temperature sensor 2, an intake pressure sensor 3, an atmospheric pressure sensor 4, a throttle sensor 5, a cam pulser 6, a crank pulser 7, It operates based on the detection result of the water temperature sensor 8 for engine cooling water. The ECU 1 is supplied with electric power from the on-board battery 9.
[0022]
The ECU 1 controls the pipe control signal c1 supplied to the switching unit 10 of the intake pipe, the injection valve energizing signal c2 supplied to the injection valve 11, and the fuel supplied to the fuel pump 12 based on the input from each sensor. A pump control signal c3 and a drive signal c4 supplied to the ignition coil 14 for energizing the spark plug 13 are output. Among these, the injection valve energizing signal c2 multiplies the basic fuel injection amount obtained based on information such as the acceleration state by the speed reduction coefficient _KFI , and determines the ON time of the injection valve 11 according to the result. The drive signal c4 is for driving the spark plug 12 by delaying the retard amount.
[0023]
FIG. 6 is a block diagram showing a configuration of a brake fluid pressure control device for brake adjustment. In the figure, the master cylinder 15 generates a master cylinder pressure corresponding to the operation amount of the brake 16. The hydraulic pressure control valve 17 applies a brake pressure corresponding to the master cylinder pressure to the wheel cylinder 18 acting on the rear wheel of the vehicle. On the other hand, the hydraulic pressure control valve 17 is connected to an external hydraulic pressure source 19 that generates hydraulic pressure regardless of the brake operation, and the hydraulic pressure control valve 17 controls the output hydraulic pressure of the external hydraulic pressure source 19. A solenoid 20 is provided. The thrust by the master cylinder pressure is controlled by the output hydraulic pressure of the external hydraulic pressure source 19, and the brake pressure is thereby changed.
[0024]
The drive current control unit 21 of the solenoid 20 calculates a brake amount command value based on the PID calculation value, and outputs a solenoid drive current corresponding to the brake amount command value. In this way, the brake pressure can be changed according to the supplied solenoid driving current to reduce the speed. As such a brake fluid pressure control device, the one described in JP-A-6-286590 can be used.
[0025]
FIG. 7 is a front view of the instrument panel (meter) of the vehicle. The instrument panel 22 is provided with a speedometer 23, a tachometer 24, a liquid crystal display 25, and a liquid crystal warning display panel (display unit) 26. The display 25 has a function of digitally displaying an odometer / trip meter, a clock display, a fuel amount display, a coolant temperature display, and the like. The warning display panel 26 displays an excess speed with respect to the scheduled speed and characters (an example is shown in an enlarged manner) for guiding the speed excess. The warning display panel 26 is a liquid crystal display and may be integrated with the liquid crystal display 25. In this case, only one liquid crystal is required and the cost is reduced. In the present embodiment, since it is provided near the upper part of the speedometer 23, it is sufficient to move the line of sight slightly to confirm the current speed after recognizing that the speed is exceeded.
[0026]
As described above, in the present embodiment, when a curve is detected, whether or not the current vehicle speed exceeds a speed suitable for traveling on the curve is determined in consideration of the bank angle. did.
[0027]
【The invention's effect】
According to the first to fifth aspects of the present invention, it is displayed that the appropriate turning speed according to the encountered curve is exceeded and the driver is prompted to suppress the speed, while the curve is increased even if the bank angle is increased. When the speed is such that the vehicle cannot turn, the vehicle speed is forcibly reduced toward the limit speed. Thus, according to the present invention, the speed of the vehicle is limited to an appropriate curve passing speed in consideration of the bank angle unique to the motorcycle.
[Brief description of the drawings]
FIG. 1 is a block diagram showing main functions of a speed display device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing an operation of the speed display device according to the embodiment of the present invention.
FIG. 3 is a relationship diagram between a speed reduction coefficient and a PID calculation value.
FIG. 4 is a relationship diagram between an ignition timing retard amount and an OID calculation value.
FIG. 5 is a diagram showing a hardware configuration for fuel supply amount adjustment and ignition timing adjustment.
FIG. 6 is a block diagram showing a configuration of a brake fluid pressure control device.
FIG. 7 is a front view of an instrument panel (meter) of the vehicle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... ECU, 2 ... Intake temperature sensor, 3 ... Intake pressure sensor, 4 ... Atmospheric pressure sensor, 5 ... Throttle sensor, 6 ... Cam pulser, 7 ... Crank pulser, 8 ... Water temperature sensor, 11 ... Injection valve, 13 ... Spark plug 30 ... Irradiation unit 31 ... Light receiving unit 32 ... Distance calculation unit 33 ... Curve detection unit 35 ... Speed table 26 ... Display unit 37 ... Speed limit unit

Claims (4)

A curve detection means for detecting the size of the curve encountered,
Vehicle speed detection means for detecting the current speed of the vehicle;
A first turning speed at which the vehicle can run at the first bank angle at which the vehicle body contacts and a second turning speed at which the vehicle can run at the second bank angle smaller than the first bank angle, and the vehicle speed detecting means. Control means including display means for displaying a display for notifying the driver of overspeed when the current speed exceeds the second turning speed based on the current speed detected in step A speed display device characterized by that . When the current speed exceeds the second turning speed , the control means is configured to display on the display means an amount of speed exceeding the second turning speed. The speed display device according to claim 1 . The speed limiting means for converging the speed of the vehicle toward the first turning speed when the current speed exceeds the first turning speed is provided. Speed display device. 4. The speed display device according to claim 1, wherein the second bank angle is selected between 70% and 90% of the first bank angle . 5.

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