METHOD AND DEVICE FOR IMPLEMENTING AUTONOMOUS BRAKING IN A SINGLE-TRACK MOTOR VEHICLE

Description

State of the art

[0001] The unpublished DE 10 2018 221 720.3 relates to a method for carrying out autonomous braking in a single-track motor vehicle, in which the need for a vehicle deceleration is detected by means of an environmental sensor system, depending on this, a driver-independent vehicle deceleration is initiated, after the vehicle deceleration has been initiated, a driver readiness value characterizing the driver's readiness to master the vehicle deceleration maneuver is determined and, depending on the driver readiness value, the temporal course of the vehicle deceleration is continued. Disclosure of the invention

[0002] The invention relates to a method according to claim 1 for carrying out a driver-independent or autonomous braking in a single-track motor vehicle, in which by means of an environmental sensor system, the need for a driver-independent vehicle deceleration or driver-independent braking or autonomous braking is detected, if the need for a vehicle deceleration exists, a driver-independent test braking process with a predetermined length of time is carried out before the implementation of the test braking process, during or after the implementation of the test braking process, a driver readiness value characterising the driver's readiness to control the vehicle deceleration detected as necessary is determined and after completion of the test braking process, the driver-independent vehicle deceleration is initiated, whereby the temporal course of the

[0003] Vehicle deceleration depends on the driver's readiness. The invention makes it possible to reduce the risk during automatic emergency braking of a two-wheeler. A driver who is unprepared for braking and is distracted can completely lose control of the two-wheeler in such a situation. For this reason, it is sensible to include a driver readiness factor that characterizes the driver's readiness to master the vehicle deceleration maneuver in the automatic braking maneuver or emergency braking maneuver. The test braking process leads to a short-term deceleration and is designed in such a way that it is not critical even if the driver is not physically ready to brake, e.g. when looking to the side or riding with one hand. The test braking process is implemented by reducing the engine torque or by reducing the engine torque while simultaneously increasing the braking torque on one or both wheels of the motorcycle.The test braking process is effective only for a short time and only decelerates the motorcycle slightly. The test braking process acts as a warning to inattentive or distracted riders and can therefore also be referred to as a warning jerk.

[0004] An advantageous embodiment of the invention is characterized in that the environmental sensor system is a radar sensor, a lidar sensor, or a video sensor. Such sensor systems are already widely used in the passenger car sector and can also be used in the two-wheeled sector.

[0005] An advantageous embodiment of the invention is characterized in that the driver readiness variable can assume at least two different values.

[0006] An advantageous embodiment of the invention is characterized in that the driver readiness variable can assume two values, where one of the two values ​​signals a driver state ready for the vehicle deceleration maneuver, the other of the two values ​​signals a driver state not ready for the vehicle deceleration maneuver.

[0007] An advantageous embodiment of the invention is characterized in that when the driver is ready, the autonomous braking is carried out with a planned target braking force curve; when the driver is not ready, the autonomous braking is carried out with a braking force curve which has a lower deceleration and / or a lower jerk compared to the braking force curve when the driver is ready.

[0008] By performing emergency braking at a lower intensity when the driver is deemed unready, the risk of the driver falling due to loss of control of the two-wheeler can be reduced. However, the weaker emergency braking draws a distracted driver's attention to the current driving situation, as the emergency braking also acts as a driver warning.

[0009] An advantageous embodiment of the invention is characterized in that the driver readiness value is determined after initiation of the test braking process based on the output signals of an inertial sensor system attached to the motor vehicle.

[0010] An advantageous embodiment of the invention is characterized in that the driver readiness value is determined after initiation of the test braking process based on the steering angle and / or the steering torque.

[0011] An advantageous embodiment of the invention is characterized in that the driver readiness value is determined after initiation of the test braking process based on the output signals of pressure-sensitive touch sensors attached to the motor vehicle.

[0012] An advantageous embodiment of the invention is characterized in that the driver readiness value is determined after initiation of the test braking process based on the output signals of wheel speed sensors or suspension travel sensors.

[0013] The invention further comprises a device for carrying out a method according to the invention just described, comprising at least one environmental sensor system which is set up to detect the need for a vehicle deceleration, a control unit which is set up, if the need for a vehicle deceleration exists, to carry out a driver-independent test braking operation with a predetermined time duration before the implementation of the deceleration, and is further set up to determine, during or after the implementation of the test braking operation, a driver's readiness for controlling the vehicle deceleration detected as necessary, and is further set up to initiate a vehicle deceleration after completion of the test braking operation, wherein the temporal course of the vehicle deceleration is dependent on the driver's readiness variable. This is in particular a control unit,in which the program code for carrying out the method according to the invention is stored.,

[0014] The drawing includes the Figures 1 to 3 .

[0015] In Fig. 1 the chronological sequence of an embodiment of the invention is shown.

[0016] In Fig. 2 A state diagram for three states is shown, two of which are driver states.

[0017] In Fig. 3 is a schematic side view of a motorcycle with essential motorcycle components usable for the invention.

[0018] The ongoing development of advanced assistance systems for motorcycle riders requires precise knowledge of the rider's condition. For example, if automatic braking is initiated, the rider must be ready for it. This requires, in particular, physical readiness. For complete control, the motorcycle must be controlled with both hands. Using suitable sensors, this readiness—for example, whether the rider has both hands on the handlebars or not—can be detected while a braking maneuver has already been initiated.

[0019] As with passenger cars, it can be assumed that a warning is issued before automatic emergency braking is applied on motorcycles. The warning jolt indicating an imminent risk of collision, possibly followed by automatic emergency braking, seems particularly suitable for motorcycles, since, unlike in a car, visual and acoustic warning signals are more difficult to perceive when riding a motorcycle.

[0020] The invention involves detecting the rider's state and thus the motorcyclist's physical readiness to brake for subsequent automatic emergency braking during the warning jolt using sensors already installed on the vehicle. The triggering and the extent or strength of the automatic emergency braking depend on the detected rider state.

[0021] Predictive environmental sensors can monitor the surroundings and detect an impending collision. To alert the rider of this before automatic emergency braking, a warning jolt is triggered. The warning jolt corresponds to a brief deceleration and is designed to be non-critical even if the rider is not physically ready to brake, e.g., if they are looking to the side or riding one-handed. The warning jolt is implemented by reducing engine torque or by reducing engine torque while simultaneously increasing braking torque on one or both wheels of the motorcycle. The warning jolt is effective only for a short time and decelerates the motorcycle only slightly.

[0022] The invention involves modeling the driver's state by measuring the overall system reaction to the warning jolt. In a first step, the driver's readiness to brake can be deduced, for example, from the inertial sensor measurement. If, for example, the driver has only one hand on the handlebars during the brief deceleration caused by the warning jolt, the driver's bracing moment causes the handlebars to move. This movement causes a change in the dynamics of the overall system, which is recorded by the inertial measurement technology. From this, it can be concluded that the driver is not ready for the subsequent nominal automatic emergency braking maneuver.

[0023] Ideally, inertial sensors can measure the motorcycle's angular rates and decelerations in all three spatial directions. However, versions of the invention can also use only individual inertial signals. In one embodiment of the invention, the model for driver state detection uses exclusively the measured roll rate, i.e., the rotation rate around the motorcycle's longitudinal axis. One embodiment uses the vehicle yaw rate in addition to the vehicle roll rate, i.e., the rotation of the vehicle around the vertical axis, in the model for driver state detection. Another embodiment uses the vehicle roll rate, yaw rate, and lateral acceleration.

[0024] In order to detect the driver's condition during the warning jolt, signals from a steering angle sensor are also evaluated in addition to signals from the inertial sensor system.

[0025] To further extend the model for detecting the driver condition, additional sensors can be evaluated: Steering torque sensors to measure steering response. Suspension travel sensors to measure the pitch of the vehicle. Wheel speed sensors. Pressure-sensitive touch sensors to measure the degree of support at contact points, such as handlebars, knees, or feet.

[0026] Depending on the detected driver condition, the subsequent automatic emergency braking is triggered if necessary. If the driver condition "ready to brake" is detected, then nominal automatic emergency braking is initiated. If the driver condition "not ready to brake" is detected, then automatic braking is triggered with an adjusted deceleration, so that the deceleration is not critical even if the driver is not ready to brake. In one version of adjusted braking, the amount of deceleration can be reduced compared to the nominal value. In another version, the jerk, i.e., the gradient of the deceleration build-up, can also be reduced.

[0027] For example, the driver model can contain three states, as shown in Fig. 2 There, block 200 indicates the "neutral" state, block 201 the "not ready to maneuver" state, and block 202 the "ready to maneuver" state. It should be noted that the "ready to maneuver" state is the state assumed before the driver state has been determined, which can be either "ready to maneuver" or "not ready to maneuver."

[0028] Fig. 1shows the chronological sequence of an embodiment of the invention. After starting the method in block 101, an environment detection is performed in block 102. Subsequently, in block 103, it is determined whether automatic braking or emergency braking is required. If this is the case, a driver-independent warning jerk or test braking process is carried out in block 104. If no braking is required, the program returns from block 103 to block 102. Based on data acquired during the warning jerk, the driver's current readiness to control the required automatic braking is determined in block 105 using a driver state model. Depending on this, a decision is made in block 106 regarding the further course of the braking process. In Fig. 1Two possible temporal braking force curves are used as examples. If the driver's state is determined to be ready to brake, automatic braking is performed as planned in block 107. If, however, the driver's state is determined to be unready to brake, automatic braking is performed in a reduced form in block 108. The process ends in block 109.

[0029] Fig. 2 shows the following states as examples in the form of a state graph: Block 200: Neutral state Block 201: Driver state "not ready for automatic braking maneuver" Block 202: Driver state "ready for automatic braking maneuver" The arrow connections pointing in both directions between the three states indicate that a transition between the different states is also possible if the driver state changes during the automatic braking maneuver.

[0030] In Fig. 3is a schematic side view of a motorcycle with the following essential motorcycle components usable for the invention. 301: Rear wheel brake 302: Rear wheel travel sensor 303: Brake control unit 304: Engine control unit 305: Front wheel brake 306: Front wheel speed sensor 307: Front wheel travel sensor 308: Ambient sensor 309: Steering angle sensor 310: Steering torque sensor 311: Driver status evaluation unit 312: Inertial measurement technology 313: Front wheel speed sensor

Claims

1. Method for carrying out autonomous braking in the case of a single-track motor vehicle, in which - the need for a vehicle deceleration is detected (103) by means of an environment sensor system, - when there is the need for a vehicle deceleration, before it is carried out a rider-independent test braking operation of a predefined length of time is carried out (104), - while or after carrying out the test braking operation (104), a rider readiness variable characterizing the readiness of the rider to control the vehicle deceleration detected as needed is ascertained (106) and - after completion of the test braking operation, the vehicle deceleration is initiated, the temporal progression of the vehicle deceleration being dependent on the rider readiness variable (107, 108).

2. Method according to Claim 1, characterized in that the environment sensor system (308) is a radar sensor system, a lidar sensor system or a video sensor system.

3. Method according to Claim 1, characterized in that the rider readiness variable can assume at least two different values.

4. Method according to Claim 3, characterized in that the rider readiness variable can assume two values, wherein - one of the two values signals a state of the rider in which the rider is ready for the vehicle deceleration manoeuvre, - the other of the two values signals a state of the rider in which the rider is not ready for the vehicle deceleration manoeuvre.

5. Method according to Claim 4, characterized in that - in the case of a ready state of the rider, the autonomous braking is carried out with a planned setpoint braking force progression (107), - in the case of an unready state of the rider, the autonomous braking is carried out with a braking force progression which has a lower deceleration and / or a less intense jolt in comparison with the braking force progression in the case of a ready state of the rider (108).

6. Method according to Claim 1, characterized in that the rider readiness variable is ascertained after initiating the test braking operation on the basis of the output signals of an inertial sensor system (312) mounted on the motor vehicle.

7. Method according to Claim 1, characterized in that the rider readiness variable is ascertained after initiating the test braking operation on the basis of the steering angle and / or the steering torque.

8. Method according to Claim 1, characterized in that the rider readiness variable is ascertained after initiating the test braking operation on the basis of the output signals of pressure-sensitive contact sensors mounted on the motor vehicle.

9. Method according to Claim 1, characterized in that the rider readiness variable is ascertained after initiating the test braking operation on the basis of the output signals of wheel-speed sensors (306, 313) or compression-travel sensors (307).

10. Device for carrying out a method according to one of Claims 1 to 9, including at least an environment sensor system, which is set up so as to detect the need for a vehicle deceleration, and a control unit, which is set up so as, when there is the need for a vehicle deceleration, before it is carried out to carry out a rider-independent test braking operation of a predefined length of time, and is also set up so as, while or after carrying out the test braking operation, to ascertain a rider readiness variable characterizing the readiness of the rider to control the vehicle deceleration detected as needed and is also set up so as, after completion of the test braking operation, to initiate vehicle deceleration, the temporal progression of the vehicle deceleration being dependent on the rider readiness variable.