Method for operating a tilting vehicle

Abstract

The invention relates to a method for operating a tilting vehicle that comprises a vehicle frame, a front wheel, a rear wheel, a drive attached to the vehicle frame and able to drive the rear wheel, a rear wheel swing arm which is attached to the vehicle frame and on which the rear wheel is arranged so as to be able to rotate, a suspension strut that supports the rear wheel swing arm on the frame, a brake unit able to be actuated by a brake actuation means and able to brake at least the rear wheel, and a control unit to which a sensor means is functionally assigned, the control unit being able to detect the driving state of the tilting vehicle, storing a maximum braking torque of the rear wheel for each driving state, such as speed of the tilting vehicle, and being able to actuate the drive and the brake unit.

Description

[0001] Method for operating a tilting vehicle

[0002] The invention relates to a method for operating a tilting vehicle.

[0003] The maximum deceleration of a tilting vehicle in dry road conditions is limited, among other things, by the rear wheel losing contact with the ground due to dynamic wheel load transfer. The deceleration at which the rear wheel lifts off depends essentially on the relationship between the wheelbase, the height of the center of gravity, and the position of the center of gravity in the vehicle's longitudinal direction.

[0004] An object of an embodiment of the invention is to propose a method for operating a tilting vehicle with which the maximum deceleration of a motorcycle can be increased.

[0005] This object is achieved by a method for operating a tilting vehicle, which has a vehicle frame, a front wheel, a rear wheel, a drive which is fixed to the vehicle frame and by means of which the rear wheel can be driven, a rear wheel swing arm which is fixed to the vehicle frame and on which the rear wheel is rotatably arranged, a spring strut by means of which the rear wheel swing arm is supported on the frame, a brake unit which can be controlled by a brake actuating means and by means of which at least the rear wheel can be braked, and a control unit to which a sensor means is functionally assigned, by means of which the driving state of the tilting vehicle can be detected, in which a maximum braking torque of the rear wheel is stored for each driving state, such as the speed of the tilting vehicle, and by means of which the drive and the braking unit can be controlled, with the steps: a.Actuating the brake actuating means and increasing the braking torque at least at the rear wheel of the tilting vehicle by the braking unit; b. Detecting whether the maximum braking torque at the rear wheel has been reached or exceeded in the current driving condition by the control unit; c. Lowering the center of gravity of the tilting vehicle; and d. Increasing the maximum braking torque at the rear wheel beyond the maximum braking torque for the driving condition by the braking unit.

[0006] By lowering the center of gravity of the tilting vehicle when the maximum braking torque on the rear wheel is detected to be reached or exceeded in the current driving condition, the maximum braking torque on the rear wheel can be increased above the driving condition with a normal center of gravity height, whereby the braking effect of the tilting vehicle can be increased.

[0007] The maximum deceleration at which the rear wheel lifts off depends essentially on the relationship between the wheelbase, the height of the center of gravity, and the position of the center of gravity in the vehicle's longitudinal direction. The longer the wheelbase and the lower and further back the center of gravity, the higher the maximum deceleration at which the rear wheel lifts off. By lowering the center of gravity, the rear wheel only lifts off at an increased maximum deceleration, whereby the maximum braking torque on the rear wheel can be increased beyond the normal state. A driving state of a tilting vehicle includes, for example, the speed of the tilting vehicle, the angle of inclination relative to a vertical line, and, if applicable, the coefficient of friction of the road surface depending on dry or wet road conditions, etc.

[0008] The brake actuation means may comprise a manually operated handbrake, a foot-operated footbrake, and / or an automatic brake. The automatic brake may, for example, be associated with a collision monitoring unit.

[0009] A tilting vehicle is understood to mean bicycles, motorcycles or motorcycle-like motor vehicles, such as scooters, in particular two-, three- or four-wheeled scooters, tilting trikes, quads or the like.

[0010] The center of gravity of the tilting vehicle can be lowered in any way. For example, a seat on the tilting vehicle can be lowered when a braking event is detected, thereby lowering the center of gravity of the entire system, consisting of the driver and the tilting vehicle.

[0011] The center of gravity of the tilting vehicle can be easily lowered if lowering the center of gravity of the tilting vehicle involves compressing the spring strut.

[0012] As the spring strut of the tilting vehicle compresses, the center of gravity of the tilting vehicle is shifted towards the ground and thus lowered.

[0013] In principle, the spring strut can be compressed in any way. For example, an actuator can be provided that actively compresses the spring strut using its own drive mechanism. In a further development of the method, lowering the center of gravity of the tilting vehicle involves applying or increasing a drive torque by the drive that opposes the braking torque on the rear wheel.

[0014] In this case, the spring strut is also compressed. However, in the aforementioned embodiment, the drive is biased against the braking unit, meaning a drive torque and an opposing braking torque act on the rear wheel. This causes the rear wheel of the tilting vehicle to deflect. The braking torque is transmitted to the rear swing arm, and the drive torque to the vehicle frame. The torque balance between the vehicle frame and the rear swing arm causes the spring strut to deflect. The deflection of the rear wheel lowers the center of gravity of the tilting vehicle.

[0015] In principle, it is conceivable that the brake unit can be controlled exclusively via the brake actuation device.

[0016] In one embodiment of the method, it is provided that the brake unit of the tilting vehicle comprises an anti-lock braking system, wherein, upon actuation of the brake actuating means, the braking torque is increased at least at the rear wheel of the tilting vehicle by an active brake pressure build-up by an ABS modulator.

[0017] In such a case, the driver activates the brake actuator, and the ABS modulator, i.e., the anti-lock braking system modulator, generates excessive braking torque at the rear wheel by actively building up brake pressure. This is detected by the control unit and initiates a lowering of the center of gravity of the tilting vehicle. Detecting whether the maximum braking torque at the rear wheel has been reached or exceeded can, in principle, be done at any time.In one embodiment of the method, it is provided that the detection of reaching or exceeding the maximum braking torque at the rear wheel in the current driving state comprises detecting by the sensor means that the wheel load and / or a longitudinal force of the rear wheel falls below a limit value stored in the control unit, in particular that the detection of reaching the maximum braking torque at the rear wheel comprises detecting at least 8% longitudinal slip, in particular at least 10% longitudinal slip, in particular at least 12% longitudinal slip.

[0018] Alternatively or additionally, in a further development of the method, detecting that the maximum braking torque at the rear wheel has been reached or exceeded may include detecting complete or at least almost complete rebound of the shock absorber by the sensor means. As a result, the shock absorber is fully or at least almost fully extended shortly before or upon the rear wheel's lift.

[0019] Furthermore, the reaching or exceeding of the maximum braking torque at the rear wheel can be determined in addition to or as an alternative to the aforementioned variants by an embodiment of the method in which the detection of reaching or exceeding of the maximum braking torque at the rear wheel comprises detecting a fall below a speed-dependent, negative acceleration threshold of the vehicle's longitudinal acceleration, in particular in which the vehicle's longitudinal acceleration is determined from the wheel speed of the rear wheel.

[0020] In a further development of the latter embodiment, it is provided that the at least one sensor means comprises an inertial sensor system of the tilting vehicle, by means of which the vehicle's longitudinal acceleration is determined.

[0021] The two previously mentioned variants of the method can be improved or supplemented if the detection of reaching or exceeding the maximum braking torque at the rear wheel includes the detection of exceeding a vehicle pitch angle determined by the inertial sensor system, wherein the signals detectable by the inertial sensor system include rotation rates or angles in all three spatial axes.

[0022] Finally, it proves to be advantageous if the detection of a full braking of the tilting vehicle comprises a detection of an exceeding of a limit value of braking torque and / or braking pressure at the front wheel and / or at the rear wheel by the at least one sensor means.

[0023] Further features, details and advantages of the invention emerge from the appended patent claims, from the drawings and the following description of a preferred embodiment of the method.

[0024] The drawing shows:

[0025] Figure 1 A schematic flow diagram of an embodiment of the method according to the invention.

[0026] Figure 1 shows a schematic flow diagram of an embodiment of the method according to the invention.

[0027] In a first step 100, a brake actuation means is actuated, thereby increasing the braking torque at least at the rear wheel of the tilting vehicle via a braking unit. In a step 101, the control unit detects whether a maximum braking torque at the rear wheel has been reached or exceeded in the current driving state.

[0028] This leads to a step 102, in which the center of gravity of the tilting vehicle is lowered. The lowering of the center of gravity of the tilting vehicle can be achieved, for example, by compressing the spring strut. The compression of the spring strut can be achieved by applying or increasing a drive torque by the drive system that opposes the braking torque on the rear wheel.

[0029] In a subsequent step 103, the maximum braking torque at the rear wheel is increased by the braking unit beyond the maximum braking torque for the current driving condition. This increases the deceleration of the tilting vehicle.

[0030] The features of the invention disclosed in the above description, in the claims and in the drawings can be essential both individually and in any combination in the realization of the invention in its various embodiments within the scope of the following claims.

[0031] List of reference symbols

[0032] 100-103 Procedural steps

Claims

P a t e n t a n s p r ü c h e 1. Method for operating a tilting vehicle, which has a vehicle frame, a front wheel, a rear wheel, a drive which is fixed to the vehicle frame and by which the rear wheel can be driven, a rear wheel swing arm which is fixed to the vehicle frame and on which the rear wheel is rotatably arranged, a spring strut by which the rear wheel swing arm is supported on the frame, a brake unit which can be controlled by a brake actuating means and by which at least the rear wheel can be braked, and a control unit to which a sensor means is functionally assigned, by which the driving state of the tilting vehicle can be detected, in which a maximum braking torque of the rear wheel is stored for each driving state, such as the speed of the tilting vehicle, and by which the drive and the braking unit can be controlled, comprising the steps: a.Actuating the brake actuating means and increasing the braking torque at least at the rear wheel of the tilting vehicle by the braking unit; b. Detecting whether the maximum braking torque at the rear wheel has been reached or exceeded in the current driving condition by the control unit; c. Lowering the center of gravity of the tilting vehicle; and d. Increasing the maximum braking torque at the rear wheel beyond the maximum braking torque for the driving condition by the braking unit.

2. Method according to claim 1, characterized in that lowering the center of gravity of the tilting vehicle comprises compressing the spring strut.

3. Method according to claim 1 or 2, characterized in that the lowering of the center of gravity of the tilting vehicle comprises applying or increasing a drive torque by the drive that is opposite to the braking torque on the rear wheel.

4. Method according to one of the preceding claims, characterized in that the braking unit of the tilting vehicle comprises an anti-lock braking system, wherein upon actuation of the braking actuation means the braking torque is increased at least at the rear wheel of the tilting vehicle by an active brake pressure build-up by an ABS modulator.

5. Method according to one of the preceding claims, characterized in that the detection of reaching or exceeding the maximum braking torque at the rear wheel in the current driving state comprises detecting by the sensor means that the wheel load and / or a longitudinal force of the rear wheel has fallen below a limit value stored in the control unit, in particular that the detection of reaching the maximum braking torque at the rear wheel comprises detecting at least 8% longitudinal slip, in particular at least 10% longitudinal slip, in particular at least 12% longitudinal slip.

6. Method according to one of the preceding claims, characterized in that the detection of reaching or exceeding the maximum braking torque at the rear wheel comprises detection of a complete or at least almost complete rebound of the spring strut by the sensor means.

7. Method according to one of the preceding claims, characterized in that the detection of reaching or exceeding the maximum braking torque at the rear wheel comprises detecting a fall below a speed-dependent, negative acceleration threshold of the vehicle's longitudinal acceleration, in particular that the vehicle's longitudinal acceleration is determined from the wheel speed of the rear wheel.

8. The method according to claim 7, characterized in that the at least one sensor means comprises an inertial sensor system of the tilting vehicle, by means of which the vehicle's longitudinal acceleration is determined.

9. Method according to claim 7 or 8, characterized in that the detection of reaching or exceeding the maximum braking torque at the rear wheel comprises detecting an exceeding of a vehicle pitch angle which is determined by the inertial sensor system, wherein the signals detectable by the inertial sensor system comprise rotation rates or angles in all three spatial axes.

10. Method according to one of the preceding claims, characterized in that the detection of a full braking of the tilting vehicle comprises a detection of an exceeding of a limit value of braking torque and / or braking pressure at the front wheel and / or at the rear wheel by the at least one sensor means.

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