Autonomous driving control for a vehicle

Abstract

Autonomous driving control (120) for a vehicle (100), comprising a user-operable setting device (122) configured to continuously or quasi-continuously set a value (124a, 124b, 124c, 124d, 124e) of a driving characteristic (126, 127, 128) used by the autonomous driving control (120) to control autonomous driving of the vehicle (100), wherein the autonomous driving control (120) is configured to determine an acceleration (132, 134, 136) of the vehicle depending on the set value (124a, 124b, 124c, 124d, 124e) of the driving characteristic (126, 127, 128), characterized in that the autonomous driving control (120) is configured to control the lateral acceleration (132) of the vehicle in a range between the human perception threshold for lateral accelerations (132a), e.g. 1 m / sec 2, and the legally permissible upper limit for lateral accelerations (132b), e.g. 3m / sec 2 , wherein the autonomous driving control (120) is configured to determine the vertical acceleration (136) of the vehicle as a function of the lateral acceleration (132) of the vehicle and the set value (124a, 124b, 124c, 124d, 124e) of the driving characteristic (126, 127, 128).

Description

[0001] The invention relates to an autonomous driving control system for a vehicle.

[0002] The concept of autonomous driving is well known. However, practical applications have shown that people's sensitivity to acceleration changes differs when they are not the driver, who can actively control the vehicle's behavior, but rather a passenger with no influence on the vehicle's behavior and aware that no other person is driving the vehicle.

[0003] The document DE 10 2017 208 583 A1, which represents the closest prior art, discloses an autonomous driving control system for a vehicle according to the preamble of claim 1.

[0004] Furthermore, reference is made to the documents DE 10 2019 124 339 B3 and WO 2016 / 197 068 A1.

[0005] It is therefore the object of the present invention to provide an improved autonomous driving control.

[0006] According to the present invention, this object is achieved by an autonomous driving controller for a vehicle, comprising a user-operable setting device configured to continuously or quasi-continuously set a value of a driving characteristic used by the autonomous driving controller to control autonomous driving of the vehicle.

[0007] In existing autonomous driving systems, the passenger has no way to influence the vehicle's driving behavior. It is important to note that even according to the present invention, the passenger is still a passenger who does not control the vehicle's behavior. The vehicle is still fully under the control of the autonomous driving controller. However, the passenger can inform the autonomous driving controller whether he / she wishes to be driven according to a smoother or more comfortable driving characteristic or according to a sportier driving characteristic.

[0008] It should be noted that the inventive approach differs from the known approach of manual driving, where the characteristics of suspension, steering or powertrain can be switched to predefined settings, for example Comfort - Normal - Sport, since in manual driving mode the driver still has full control over the behavior of the vehicle and thus always remains in his / her preferred range.

[0009] It should also be noted that the inventive approach differs from known advanced driver assistance systems (ADASs), where the driver's control is limited because the system partially takes over control. Therefore, the driver is not always able to precisely target their individually preferred range, as the ADAS's behavior is predetermined. If the driver wishes to return to their individually preferred range, they must override the system and thus return to manual mode.

[0010] And even if ADAS adapts to the driver's driving style, these systems are not able to take into account the change in the driver's sensitivity to acceleration changes when he is no longer a driver who can actively influence the vehicle's behavior, but only a passenger, since most drivers would not accept their own driving style as a passenger.

[0011] In contrast to these state-of-the-art systems, autonomous driving control allows to increase the passenger's enjoyment of autonomous driving by offering the possibility to adjust the driving characteristics of the vehicle and to adapt them to the passenger's individually preferred range under autonomous driving conditions using the adjustment device.

[0012] According to the invention, the autonomous driving control is configured to determine the acceleration of the vehicle as a function of the set value of the driving characteristic. In this context, it should be noted that the term "acceleration" does not necessarily refer to positive accelerations, i.e., accelerations that increase the vehicle speed. Rather, it is conceivable that this term also refers to negative accelerations, i.e., accelerations that reduce the vehicle speed.

[0013] For example, the user-operable adjustment device can be used to continuously or quasi-continuously adjust the value of the ride characteristic between "smooth", which corresponds to lower acceleration levels with a gentler gradient, and "direct", which corresponds to higher acceleration levels with a steeper gradient.

[0014] Of course, the autonomous driving control system must determine acceleration in all three spatial directions. However, since practical tests have shown that passengers are most sensitive to changes in lateral acceleration, it is proposed that the autonomous driving control system be configured to determine the vehicle's lateral acceleration as the leading parameter.

[0015] In particular, the autonomous driving control is designed to limit the lateral acceleration of the vehicle in a range between the human perception threshold for lateral acceleration, for example 1 m / sec 2 , and the legally permissible upper limit for lateral acceleration, for example 3m / sec 2 , to determine.

[0016] Furthermore, it is proposed that the autonomous driving control can be configured to increase the lateral acceleration essentially linearly depending on the value of the driving characteristic.

[0017] In this context, it should also be noted that lateral accelerations occur not only when cornering or turning, but also during left and right steering corrections while driving on a straight road. It has been shown that passengers are sensitive to a specific frequency range in which left and right steering corrections follow one another, and are particularly sensitive to the time derivative of lateral acceleration, the so-called jerk, which gives the passenger the impression of a sporty driving style.

[0018] Therefore, in order to comply with current legislation for autonomous driving on the one hand, but to improve human perception on the other hand, it is further proposed that the autonomous driving control system can be configured to further determine, in a driving characteristic range adjacent to the direct end of driving characteristics, the derivative of the lateral acceleration of the vehicle as a function of the set value of the driving characteristic, and to limit the lateral acceleration to the legally permissible upper limit, of e.g. 3 m / sec 2 , while the derivative of the lateral acceleration can be set to values ​​that increase towards the direct end of driving characteristics.

[0019] Since the lateral acceleration is used as the leading parameter, according to the present invention, the autonomous driving controller is configured to determine the vertical acceleration of the vehicle depending on the lateral acceleration of the vehicle and the set value of the driving characteristic.

[0020] According to a further embodiment of the present invention, it is proposed that the autonomous driving control can be configured to determine the longitudinal acceleration of the vehicle as a function of the lateral acceleration of the vehicle and the set value of the driving characteristic.

[0021] In particular, the autonomous driving control can be configured to control the longitudinal acceleration of the vehicle in a range between the human perception threshold for longitudinal accelerations, e.g. 0.5 m / sec 2 , and the legally permissible upper limit for longitudinal accelerations, e.g. 3m / sec 2By limiting the range to these limits, the autonomous driving control system can operate faster and comply with current legislation.

[0022] Furthermore, the autonomous driving control system can be configured to set the longitudinal acceleration of the vehicle such that the gradient of the longitudinal acceleration continuously increases from lower values ​​of the driving characteristic to higher values ​​of the driving characteristic. This improves the perception of a comfortable or sporty driving characteristic.

[0023] With regard to vertical acceleration, it has been shown that human perception is dominated by the power density of the vertical movement of the vehicle's center of gravity in a predetermined low frequency range, hereinafter referred to as the vertical low-frequency power density. It is therefore proposed that the autonomous driving control system can be configured to determine the vehicle's vertical acceleration such that the vertical low-frequency power density first decreases and then increases from lower values ​​of the driving characteristic to higher values ​​of the driving characteristic.

[0024] At lower values ​​of the driving characteristic, it must be taken into account that passengers are prone to motion sickness if the vertical low-frequency power density is too low. And at higher values ​​of the driving characteristic, it must be taken into account that large amplitudes of vertical movement are perceived as unpleasant by passengers.

[0025] In the manner described above, a set of three acceleration values ​​is obtained: a lateral acceleration value, a longitudinal acceleration value, and a vertical acceleration value, each acceleration being orthogonal to the other two. However, passengers do not consider each set of acceleration values ​​to be a harmonic set of accelerations that they like. On the contrary, they have a fairly clear idea of ​​which ranges of longitudinal and vertical acceleration harmoniously match a given lateral acceleration. To accommodate this idea, it is further proposed that the autonomous driving controller can be configured to check whether the determined value of the vehicle's longitudinal acceleration is within predetermined limits and / or whether the determined value of the vehicle's vertical acceleration is within predetermined limits.

[0026] It goes without saying that the limit values ​​of the longitudinal acceleration and the vertical acceleration respectively reflect the limits of the harmonic set of accelerations.

[0027] To ensure that the set of three acceleration values ​​on the basis of which the autonomous driving controller controls the vehicle is a set considered harmonious, the autonomous driving controller may be configured to set the corresponding predetermined value to the corresponding limit value if the predetermined values ​​of the longitudinal acceleration of the vehicle and / or the vertical acceleration of the vehicle are found to exceed the predetermined limit values, and to recalculate the predetermined value of the corresponding other accelerations. In this case, a lower limit for the lateral acceleration may be based on a human perception threshold, e.g., 1 m / sec. 2, and an upper limit can be based on the current legislation for autonomous driving and e.g. 3m / sec 2 be.

[0028] For example, the user-operable adjustment device may be an actively operable adjustment device, for example an adjustment device selected from the group consisting of a selector switch, a slider control, a gesture control, and a voice control.

[0029] As an alternative, the user-operable adjustment device may be a passively operable adjustment device, for example, an adjustment device operable by an occupant monitoring system.

[0030] It should be emphasized here that the autonomous driving control system according to the present invention can be partially or entirely realized by a processor such as a central processor (CPU) or the like executing a program (software) stored in a memory. All or some of its components can be realized by hardware such as a large-scale integration (LSI), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA), and / or by the cooperation of software and hardware. The program can be stored in advance in a storage device such as a hard disk drive (HDD) or a flash memory, and it can be stored in a removable storage medium such as a DVD or CD-ROM and installed on a storage medium when the storage medium is mounted in a drive.

[0031] Finally, it should be noted that the present invention can be applied not only to passenger cars, but also to buses, trucks and other types of vehicles.

[0032] The invention will be described in more detail with reference to the accompanying drawings using a specific embodiment, in which: Fig. 1 shows a schematic structure of a vehicle equipped with an autonomous driving control system according to the present invention; Fig. Figure 2 schematically shows a user-operable adjustment device together with various driving characteristics; Fig. 3a to 3c show the course of a lateral acceleration ( Fig. 3a), a longitudinal acceleration ( Fig. 3b) and a vertical acceleration ( Fig. 3c) from low values ​​to higher values ​​of the driving characteristics according to the invention; and Fig. 4 shows a flowchart of a program executed by the autonomous driving controller.

[0033] In Fig. 1, a vehicle is generally designated by reference numeral 100. The vehicle 100 includes a chassis 102, a brake 104, a drivetrain 106, a steering device 108, sensors 110, a vehicle motion control device 112, a trajectory planning device 114, and an autonomous driving controller 120. For coordinated vehicle motion, the chassis 102, the brake 104, the drivetrain 106, the steering device 108, and the trajectory planning device 114 are connected to the vehicle motion control device 112.

[0034] Based on the data received from devices 102, 104, 106, 108, and 114, vehicle motion control device 112 determines a motion adjustment of vehicle 100 and controls vehicle 100 to travel accordingly, e.g., by adjusting vehicle acceleration. For this purpose, vehicle motion control device 112 outputs a corresponding output signal to chassis 102 and / or brake 104 and / or drivetrain 106 and / or steering device 108. Furthermore, trajectory planning device 114 is connected to sensors 110, vehicle motion control device 112, and autonomous driving controller 120.

[0035] Furthermore, it should be noted that a feedback controller may be installed in the vehicle motion control device 112, comprising a feedforward control device and a steering wheel angle control device that determines the frequency of the left and right steering corrections and / or the amplitude of these steering corrections based on the input data received from the trajectory planning device 114 and the at least one environmental measurement value of the vehicle, e.g., measured by the at least one vehicle sensor 110.

[0036] According to the present invention, the autonomous driving control 120 comprises a user-operable adjustment device 122, for example a rotary knob (see Fig. 2) which can be operated by a passenger of the vehicle in a continuous or quasi-continuous manner to determine the value of a driving characteristic and which outputs the driving characteristic to the autonomous driving controller 120.

[0037] In particular, the driving characteristic can take any value on a predefined scale 124 (see Fig. 2). The scale 124 can be either a continuous scale or a discrete scale with a large number of values. In one embodiment, the scale 124 can extend from a lowest value at one end 124a, corresponding to a comfortable or smooth driving characteristic 126, through intermediate values ​​124b of the scale 124, corresponding to regular driving characteristics 127, to a highest value at the corresponding other end 124c, corresponding to a sporty or direct driving characteristic 128. As can be seen from the Fig. 2, a request to change the driving force F of the vehicle triggered by the autonomous driving control 120 is implemented very slowly in the case of the gentle driving characteristic 126, while it is implemented very quickly in the case of the direct driving characteristic 128.

[0038] It should be noted that although the user-operable adjustment device 122 in Fig. 2 as a rotary knob, other types of user-operable adjustment devices 122 may also be used, e.g., linear controls. Furthermore, not only active user-operable adjustment devices 122 may be used, i.e., adjustment devices that are actively operated by a passenger, but also passive user-operable adjustment devices that determine the passenger's degree of satisfaction with the current driving characteristics based on the passenger's behavior, e.g., the passenger's facial expressions.

[0039] On the basis of the received value 124a, 124b, 124c of the driving characteristic 126, 127, 128, the autonomous driving control 120 determines the acceleration of the vehicle 100 in all three spatial directions according to the Fig. 3a to 3c, namely a lateral acceleration 132 according to the diagrams shown in Fig. 3a, a longitudinal acceleration 134 according to the diagram in Fig. 3b and a vertical acceleration 136 according to the diagram in Fig. diagram shown in Figure 3c.

[0040] The set of three acceleration values—lateral acceleration 132, longitudinal acceleration 134, and vertical acceleration 136—must be harmonious with each other so that passengers can perceive a comfortable overall vehicle motion. A harmonious set of accelerations, according to which all three acceleration values ​​are determined at or at least close to their lower limits, smooths the vehicle motion, which passengers perceive as comfortable driving. A harmonious set of accelerations, according to which all three acceleration values ​​are determined at or at least close to their upper limits, results in a direct vehicle motion, which passengers perceive as sporty driving.

[0041] Since practical tests have shown that passengers are most sensitive to changes in lateral acceleration 132, the autonomous driving controller 120 may determine the lateral acceleration 132 of the vehicle as a leading parameter, ie, as a parameter that is determined before determining the longitudinal acceleration 134 and the vertical acceleration 136.

[0042] One problem that has arisen is that the lateral acceleration 132 must exceed a certain threshold 132a in order to be perceived by a passenger, e.g. 1m / sec 2 On the other hand, the legislation limits the lateral acceleration 132 to an upper limit 132b, e.g. 3m / sec 2 . Accordingly, the autonomous driving controller 120 may determine the lateral acceleration 132 of the vehicle in a range between the human perception threshold 132a at the gentle end and the legally permissible upper limit 132b at the direct end 124c.

[0043] As practical tests have shown, the lateral acceleration 132 near the direct end 124c alone is not capable of conveying a sporty driving experience to the passenger. Rather, it has been shown that passengers near the direct end 124c are more sensitive to the lateral jerk 133, i.e., the time derivative of the lateral acceleration 132.

[0044] Against this background, the lateral acceleration 132 begins with the human perception threshold 132a at the gentle end 124a, then increases almost linearly depending on the scale value 124 up to a predetermined value 124d, which is approximately 80% of the entire extent of the scale 124, where it reaches the legally permissible upper limit 132b. Between the predetermined scale value 124d and the upper end 124c of the scale 124, the lateral acceleration 132 remains constant at the legally permissible upper limit 132b, while the lateral jerk 133, which remained constant at a lower value 133a up to the predetermined scale value 124d, now continuously increases from the lower value 133a to a higher value 133b.

[0045] After determining the lateral acceleration 132 as the leading parameter, the autonomous driving control 120 now determines the longitudinal acceleration 134 and the vertical acceleration 136.

[0046] Similar to the lateral acceleration 132, the longitudinal acceleration 134 must overcome a certain threshold 134a to be perceived by a passenger. For this reason, and to comply with current legislation, the autonomous driving controller 120 can determine the longitudinal acceleration 134 of the vehicle in a range between a human perception threshold for longitudinal acceleration 134a at the gentle end 124a and a legally permissible upper limit 134b for longitudinal acceleration at the direct end 124c ( Fig. 3b).

[0047] Since the human body is sensitive to the duration of the longitudinal acceleration 134, the longitudinal acceleration 134 can be adjusted so that its gradient increases continuously from lower values ​​at the gentle end 124a to higher values ​​at the direct end 124c.

[0048] For the human perception of vertical acceleration 136, a vertical low-frequency power density 138 is dominant, ie the power density of the vertical movement of the vehicle's center of gravity in the given low-frequency range. Therefore, Fig. 3c the vertical low-frequency power density 138 as a parameter representing the vertical acceleration.

[0049] Since passengers tend to experience motion sickness when the vertical low-frequency power density 138 assumes lower values ​​and since higher values ​​are perceived as unpleasant, a balanced curve of the vertical low-frequency power density 138 must be determined. Therefore, the autonomous driving controller 120 can determine the vertical acceleration 136 of the vehicle such that the vertical low-frequency power density 138 first decreases from a small value 138a at the gentle end to a smallest value 138b at a driving characteristic value 124e and then increases to a higher value 138c at the direct end 124c.

[0050] The autonomous driving controller 120 adapts the set of accelerations within predetermined limits 132a, 132b, 134a, 134b, 138b, 138c taking into account the driving situation to ensure that the set of accelerations is a set that is considered harmonious.

[0051] In the following, the operation of an embodiment of the autonomous driving control 120 is described with reference to the flowchart of Fig. 4 described in more detail.

[0052] The process begins with the start of driving of the vehicle 100 in step S100.

[0053] The process then proceeds to step S110, in which the autonomous driving controller 120 is activated.

[0054] After step S110, the process proceeds to step S120, in which a passenger sets the user-operable adjustment device 122 to a value between 124a and 124c to determine the desired driving characteristic.

[0055] The process then proceeds to step S130, where it is determined whether the current driving situation allows a different driving characteristic setting or not. If this is not the case (step S130: NO), the process proceeds to step S140, where the user is informed that no other driving characteristic setting is permitted due to the current driving situation, so the current setting is retained. The process then returns to step S120.

[0056] If another driving characteristic setting is permitted (step S130: YES), the process proceeds to step S150, where the values ​​of the lateral acceleration 132, the longitudinal acceleration 134, and the vertical acceleration 136 are determined. The longitudinal acceleration 134 and the vertical acceleration 136 are determined depending on the lateral acceleration 132 as the leading parameter.

[0057] The process then proceeds to step S160, in which it is determined whether the values ​​of the longitudinal acceleration 134 and / or the vertical acceleration 136, or the vertical low-frequency power density 138, are within the predetermined limit values ​​(134a, 134b, 138a, 138b). If this is not the case (step S160: NO), the process proceeds to step S170, in which the value of the longitudinal acceleration 134 and / or the value of the vertical acceleration 136, or the vertical low-frequency power density 138, if they exceed the predetermined limit values ​​(134a, 134b, 138a, 138b), are set to the respective limit value. Subsequently, the values ​​of the other respective accelerations are recalculated to form a set of lateral acceleration 132, longitudinal acceleration 134, and vertical acceleration 136, which is considered harmonic. The process then returns to step S160.

[0058] If the values ​​of the lateral acceleration 132, the longitudinal acceleration 134, and the vertical acceleration 136 are within the predetermined limit values ​​(step S160: YES), the process proceeds to step S180, in which the vehicle motion control device 112 adjusts the motion of the vehicle based on the determined values ​​of the lateral acceleration 132, the longitudinal acceleration 134, and the vertical acceleration 136.

[0059] The process then proceeds to step S190, where it is determined whether or not the passengers accept the adjusted vehicle motion. If not (step S190: NO), the process proceeds to step S120, where a passenger sets the user-operable adjustment device 122 to a value between 124a and 124c to determine the desired driving characteristic.

[0060] If the passengers accept the adjusted vehicle motion based on the determined values ​​of the lateral acceleration 132, the longitudinal acceleration 134, and the vertical acceleration 136 (step S190: YES), the process proceeds to step S200, where the adjusted set of accelerations is maintained.

[0061] After step S200, the process proceeds to step S210, where it is determined whether the vehicle is still in autonomous driving mode or not. If so (step S210: YES), the process proceeds to step S190, where it is determined whether or not the passengers accept the adjusted vehicle movement.

[0062] However, if the vehicle is no longer in autonomous driving mode (step S210: NO), the process is terminated in step S220.

Claims

[1] Autonomous driving control (120) for a vehicle (100), comprising a user-operable setting device (122) which is configured to continuously or quasi-continuously set a value (124a, 124b, 124c, 124d, 124e) of a driving characteristic (126, 127, 128) which is used by the autonomous driving control (120) to control autonomous driving of the vehicle (100), wherein the autonomous driving control (120) is configured to determine an acceleration (132, 134, 136) of the vehicle depending on the set value (124a, 124b, 124c, 124d, 124e) of the driving characteristic (126, 127, 128), characterized by , that the autonomous driving control (120) is configured to control the lateral acceleration (132) of the vehicle in a range between the human perception threshold for lateral accelerations (132a), e.g. 1 m / sec 2, and the legally permissible upper limit for lateral accelerations (132b), e.g. 3m / sec 2 , wherein the autonomous driving control (120) is configured to determine the vertical acceleration (136) of the vehicle as a function of the lateral acceleration (132) of the vehicle and the set value (124a, 124b, 124c, 124d, 124e) of the driving characteristic (126, 127, 128). [2] Autonomous driving control according to claim 1, wherein the autonomous driving control (120) is configured to increase the lateral acceleration (132) substantially linearly as a function of the value (124a, 124b, 124c, 124d, 124e) of the driving characteristic (126, 127, 128). [3] Autonomous driving control according to claim 2, wherein the autonomous driving control (120) is configured to further determine the derivative (133) of the lateral acceleration (132) of the vehicle in a driving characteristic range that borders on the direct end of driving characteristics (124c) as a function of the set value (124a, 124b, 124c, 124d, 124e) of the driving characteristic (126, 127, 128), and the lateral acceleration (132) to the legally permissible upper limit (132b), e.g. 3m / sec 2 , while the derivative (133) of the lateral acceleration is set to values that increase towards the direct end of driving characteristics (124c). [4] Autonomous driving control according to one of claims 1 to 3, wherein the autonomous driving control (120) is configured to determine the longitudinal acceleration (134) of the vehicle as a function of the lateral acceleration (132) of the vehicle and the set value (124a, 124b, 124c, 124d, 124e) of the driving characteristic (126, 127, 128). [5] Autonomous driving control according to claim 4, wherein the autonomous driving control (120) is configured to control the longitudinal acceleration (134) of the vehicle in a range between the human perception threshold for longitudinal accelerations (134a), e.g. 0.5 m / sec 2 , and the legally permissible upper limit for longitudinal accelerations (134b), e.g. 3m / sec 2 , to determine. [6] Autonomous driving control according to claim 4 or 5, wherein the autonomous driving control (120) is configured to determine the longitudinal acceleration (134) of the vehicle such that the gradient of the longitudinal acceleration increases continuously from lower values of the driving characteristic (124a) to higher values of the driving characteristic (124c). [7] Autonomous driving control according to one of claims 1 to 6, wherein the autonomous driving control (120) is configured to determine the vertical acceleration (136) of the vehicle such that the vertical low-frequency power density (138) first decreases and then increases from lower values of the driving characteristic (124a) to higher values of the driving characteristic (124c). [8] Autonomous driving control according to one of claims 4 to 7, wherein the autonomous driving control (120) is configured to check whether the determined value of the longitudinal acceleration (134) of the vehicle is within predetermined limit values (134a, 134b), and / or whether the determined value of the vertical acceleration (136) of the vehicle is within predetermined limit values (138a, 138b, 138c). [9] Autonomous driving controller according to claim 8, wherein the autonomous driving controller (120) is configured to set the corresponding determined value to the corresponding limit value when it turns out that the determined values of the longitudinal acceleration (134) of the vehicle and / or the vertical acceleration (136) of the vehicle exceed the predetermined limit values (134a, 134b, 138a, 138b, 138c), and to recalculate the determined value of the corresponding other accelerations (132, 134, 136). [10] Autonomous driving control according to one of claims 1 to 9, wherein the user-operable adjustment device (122) is an actively operable adjustment device or a passively operable adjustment device. [11] Autonomous driving control according to claim 10, wherein the user-operable setting device (122) is an actively operable setting device, for example a setting device selected from a group consisting of a selector switch, a slider control, a gesture control, and a voice control. [12] Autonomous driving control according to claim 10, wherein the user-operable adjustment device (122) is a passively operable adjustment device, for example an adjustment device operable by an occupant monitoring system.

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