METHOD FOR OPERATING A VEHICLE, COMPUTER PROGRAM, CONTROL SYSTEM, AND VEHICLE - Patent application

Abstract

A method for operating a vehicle (1), comprising the steps of receiving (S1) sensor data (S) of a sensor system (3) of the vehicle (1), the sensor data (S) comprising a current steering angle (δ) and a steering angular velocity (W) of the vehicle (1) traveling on a road (14) having a curve (13), and calculating a forward radius R of the curve (13) at a forward position (P2) that the vehicle (1) can reach after a predetermined time span T. A Formula: R O =R C -T[(L w) / (sin 2 (δ)] is the odometer-based forward radius R O where L is the distance between the front wheels (17) and the rear wheels (18) of the vehicle (1), and R C is the radius of the road (14) at the current position (P1) of the vehicle (1); and A (S6) performing a curvature control function based on A method for providing the above.

Description

[Technical field]

[0001] The present invention relates to a method for operating a vehicle, a computer program, a control system, and a vehicle comprising such a control system. [Background technology]

[0002] Modern vehicles, such as passenger cars, are nowadays usually equipped with several driver assistance systems. Examples are the Adaptive Cruise Control (ACC) system, the Lane Keeping Assist (LKA) system, the Highway Assist (HWA) system, the Traffic Jam Assist (TJA) system and the Traffic Jam Pilot (TJP) system. An important aspect of these systems is curvature control. This involves predicting the curvature of the approaching curve and the speed to adapt to it. Usually, the curvature of the road is determined based on lane marks detected by the vehicle's camera. If lane marks are not present on the road or the image data showing the lane marks is of poor quality, the current route determined from odometer data is used instead. For example, WO2020 / 001346A1 proposes to obtain the current steering wheel angle of the vehicle if no road markers are identified from the road surface image.

[0003] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to provide an improved method for operating a vehicle. Summary of the Invention

[0004] Thus, there is provided a method for operating a vehicle, the method comprising: receiving sensor data of a sensor system of the vehicle, the sensor data including a current steering angle δ and a steering angular velocity W of the vehicle traveling on a curved road; a forward radius R of the curve at a forward position P2 that the vehicle can reach after a given time span T A Formula: R O =R C -T[(L w) / (sin2 (δ)] is the odometer-based forward radius R O where δ is the steering angle, W is the steering angular velocity, L is the distance between the front and rear wheels of the vehicle, and R C is the radius of the road at the current position of the vehicle; The determined forward radius R A performing a curvature control function based on Equipped with.

[0005] Therefore, the radius of curvature of the curve on the road on which the vehicle is traveling, R A The radius R at the front position of the vehicle A is determined based on sensor data of the vehicle's steering angle sensor, in particular based on the measured current steering angle and steering angular velocity of the vehicle. Thus, the curvature of the road on which the vehicle is traveling is determined based on the odometer data. This allows for a better prediction of the curvature. Furthermore, the curvature of the road can be determined even when no lane markings are present on the road and / or no lane markings are detected in the image data of the vehicle's camera. A better prediction of the curvature of the road allows for a better curvature control of the vehicle. In particular, the advanced braking control before and / or when entering a curve can be improved, thereby improving the safety and comfort of the vehicle occupants.

[0006] The forward radius R of the curve's curvature at a forward position P2 that the vehicle can reach after a given time span T A By determining, the vehicle's driving conditions, expected state and / or nominal state of the vehicle can be predicted at the end of a predetermined time span T. The predetermined time span T can be any value within the range of, for example, 0.5 to 2.5 seconds. In particular, the predetermined time span T can have a value of, for example, 0.5 seconds, about 0.5 seconds, 1 second, about 1 second, 1.5 seconds, about 1.5 seconds, 2 seconds, about 2 seconds, 2.5 seconds, or about 2.5 seconds.

[0007] The steering angle is, for example, the angle of rotation of a steering shaft of a vehicle. The steering angle is, for example, the angle of one or more drive wheels of a vehicle. The steering angular velocity is, for example, the first derivative with respect to time of the steering angle.

[0008] Odometer-based forward radius R O is calculated, for example, based on the steering angle δ and the steering angular velocity W=dδ / dt according to the following relation: R C = L / tan(δ) (based on the trigonometric relationship of a right-angled triangle), dR C / dt=L d / dt[1 / tan(δ)], dR C / dt=-L dδ / dt / (sin 2 (δ)] R0=R C +dR C / dt, R O =R C -T[(L w) / (sin 2 (δ)] where W = dδ / dt.

[0009] The road on which the vehicle is traveling includes, for example, one or more lanes. There may be lane markings that define the lanes, i.e., marked lanes. In other cases, for example, there are no lane markings for one or more lanes, resulting in unmarked lanes. The vehicle is, for example, traveling in one of the lanes (e.g., marked or unmarked) of the road. The curve of the road is, for example, the curve of the lane (e.g., marked or unmarked) on which the vehicle is traveling. The radius of curvature of the road is, for example, the radius of curvature of the lane (e.g., marked or unmarked) on which the vehicle is traveling.

[0010] The sensor system includes, inter alia, a steering angle sensor unit. The steering angle sensor unit is based on magnetoresistance technology, for example giant magnetoresistance technology (GMR element). The steering angle sensor is, for example, fixed to the steering shaft of the vehicle. A hub gear wheel of the sensor transmits, for example, the rotational movement of the shaft to two measuring gear wheels. Each measuring gear wheel is, for example, fitted with a magnet. The magnetic field of the magnet changes its direction depending on the rotational movement. Below each magnet, a GMR sensor element may be arranged, which detects the angular position of the upper magnet. The analog value of the GMR element is, for example, converted into digital information. The steering angle sensor provides, for example, absolute steering angle values ​​over the entire steering angle range.

[0011] The sensor system of the vehicle includes further sensor units, such as, for example, one or more environmental sensor units. The environmental sensor units are configured to detect the vehicle's driving state and / or the vehicle's environment. Examples of such sensor units are a camera device for capturing surrounding images, a radar device (radio detection and ranging) for acquiring radar data, and a lidar device (light detection and ranging) for acquiring lidar data. The sensor system may further include an ultrasonic sensor, a position sensor, a rain sensor, a temperature sensor, and / or a light sensor.

[0012] The sensor units of the vehicle are each configured to output a sensor signal, for example to a driving assistance system or a parking assistance system, which for example performs assisted or (semi-)autonomous driving as a function of the detected sensor signal. In particular, the sensor units may each be configured to output a sensor signal to a control system and / or a curvature control system / unit, which performs a curvature control as a function of the detected sensor signal.

[0013] The method steps are in particular performed by a control system of the vehicle.

[0014] According to an embodiment, the nominal speed V of the vehicle at the forward position A is the determined forward radius R A and formula: V A =(A MAX ·R A ) 1 / 2 Prescribed maximum lateral acceleration A MAX is determined based on:

[0015] Furthermore, the curvature control function is adapted to control the determined nominal speed V A This is carried out based on the following:

[0016] Nominal speed in forward position V A The forward radius R is determined A and a given maximum lateral acceleration A MAX By calculating based on , a curvature control of the vehicle can be performed such that the speed of the vehicle at the forward position is equal to (or less than) the calculated nominal speed, thus avoiding the vehicle from veering off the curve and / or braking.

[0017] Maximum lateral acceleration A MAX For example, 2.5m / s 2 ~3.5m / s 2 Maximum lateral acceleration A MAX For example, 2.5m / s 2 , about 2.5m / s 2 , 3m / s 2 , about 3m / s 2 , 3.5m / s 2 , or about 3.5 m / s 2 , 2m / s 2 Below, approximately 2m / s 2 Below, 2.5m / s 2 Below, approximately 2.5m / s 2 Below, 3.5m / s 2 Less than or equal to 3.5m / s 2 It can have the following values: Maximum lateral acceleration A MAX The value of depends on the speed of the vehicle.

[0018] According to a further embodiment, the expected acceleration of the vehicle at the forward position is determined based on a current speed V C , and the nominal speed V of the vehicle at the forward position. A Further, the presence of lane markings on the road is detected, and a track quality of the detected lane markings is determined based on the sensor data, and a lane-based forward radius R of the curve at the forward position is determined based on the sensor data. L is determined based on the detected lane markings. If the determined track quality exceeds a predetermined track quality threshold and the determined expected acceleration corresponds to braking of the vehicle, the forward radius R A is the lane-based forward radius R L and the forward radius R of the odometer base O In an embodiment, the curvature control function is set equal to the minimum value of the odometer-based forward radius R O and the lane-based forward radius R L Based on the If the determined track quality exceeds the predetermined track quality threshold and the determined expected acceleration corresponds to a positive acceleration of the vehicle, the forward radius R A is the lane-based forward radius R L and the forward radius R of the odometer base O In an embodiment, the curvature control function is set equal to a maximum value of the odometer-based forward radius R O and the lane-based forward radius R L Based on the If the determined track quality is less than or equal to the predetermined track quality threshold, the forward radius R A is the forward radius R of the odometer base O In an embodiment, the curvature control function is set equal to the odometer-based forward radius R O and the lane-based forward radius R L This is carried out based on the following:

[0019] Therefore, if the track quality of the detected lane markings is too poor (i.e., below a predefined track quality threshold), the forward radius R of the curve of the road on which the vehicle is traveling is A is the odometer-based forward radius R O It can be advantageously determined based solely on the above.

[0020] Furthermore, if the track quality of the detected lane markings is within a desired range (i.e., exceeds a predetermined track quality threshold), the forward radius R of the curve of the road on which the vehicle is traveling is A is the lane-based forward radius R depending on the vehicle acceleration state (braking or positive acceleration). L or odometer-based forward radius R O may be advantageously determined to be equal to either

[0021] Current vehicle speed V C is the speed of the vehicle at the current position.

[0022] The sensor system of the vehicle includes, in particular, one or more camera devices for capturing images of the vehicle's surroundings. Furthermore, the presence or absence of lane markings on the road is detected based on image data (an example of sensor data) of the one or more camera devices of the vehicle. The camera devices include, for example, a front camera arranged on the windshield of the vehicle and configured to monitor the area in front of the vehicle. However, the one or more camera devices may also be arranged on other windows of the vehicle and / or may monitor other areas, for example the sides or rear of the vehicle.

[0023] Determining the track quality of the detected lane marks comprises, for example, determining a current track quality level of the detected lane marks. The track quality (level) of the detected lane marks corresponds, for example, to an image quality of the image data provided by the one or more camera devices. The level of track quality of the detected lane marks and / or the level of image quality of the image data provided by the one or more camera devices is, for example, determined and provided by the one or more camera devices. The predefined track quality threshold is, for example, a predefined threshold of the track quality level.

[0024] In an embodiment, the method further comprises: L Error ΔR L The step of determining the error ΔR L is, for example, a measure of the track quality of the detected lane markings. Determined error ΔR L is less than a predetermined threshold and the determined expected acceleration corresponds to the braking of the vehicle, the forward radius R A is the lane-based forward radius R L and odometer-based forward radius R O In an embodiment, the curvature control function is set equal to the minimum value of the odometer-based forward radius R O and lane-based forward radius R L may be implemented based on Determined error ΔR L is less than a predetermined threshold and the determined expected acceleration corresponds to a positive acceleration, the forward radius R A is the lane-based forward radius R L and odometer-based forward radius R O In an embodiment, the curvature control function is set equal to the maximum of the odometer-based forward radius R O and lane-based forward radius R L may be implemented based on Determined error ΔR L If is greater than or equal to a certain threshold, the forward radius R A is the odometer-based forward radius RO In an embodiment, the curvature control function is set equal to the odometer-based forward radius R O and lane-based forward radius R L This can be implemented based on the following:

[0025] Therefore, the determined lane-based forward radius R L Error ΔR L If is too large (i.e., above a certain threshold), the forward radius R of the curve of the road on which the vehicle is traveling A is the odometer-based forward radius R O It can be advantageously determined based solely on the above.

[0026] Furthermore, the determined lane-based forward radius R L Error ΔR L is within the desired range (i.e., is less than a predetermined threshold), the forward radius R of the curve on the road on which the vehicle is traveling A is the lane-based forward radius R depending on the vehicle acceleration state (braking or positive acceleration). L or odometer-based forward radius R O may be advantageously determined to be equal to either

[0027] According to a further embodiment, the lane-based forward radius R L is the formula: R L = 1 / [(6·a·T)+(2·b)], where a and b are the first two coefficients of the polynomial, and T is the predetermined time span.

[0028] A polynomial is in particular a polynomial function. A polynomial is in particular a mathematical representation of a perceived lane. A polynomial is, for example, a third-order or higher polynomial function. For example, a lane-based forward radius R L is determined based on the first two coefficients a and b of a third order polynomial. P(x)=ax 3 +bx 2 +cx+d

[0029] Furthermore, the anterior curvature can be expressed as: C A =(6 a T) + (2 b)

[0030] Furthermore, the front radius R L is given by: R L =1 / C A

[0031] According to a further embodiment, the step of performing the curvature control function comprises: computing the acceleration and / or jerk of the vehicle in relation to a current speed V of the vehicle at the current position; C , and the nominal speed V of the vehicle at the forward position. A The step of controlling based on the above is included.

[0032] In particular, by controlling the acceleration and / or jerk of the vehicle, the current speed V C to nominal speed V A It is possible to control the braking process (negative acceleration) of the vehicle over time (time evolution of braking) until the vehicle reaches the braking position. Thus, the safety and comfort of the passengers can be improved.

[0033] Vehicle jerk specifically represents the change in vehicle acceleration with respect to time. Vehicle jerk is specifically the first derivative with respect to time of vehicle acceleration and the second derivative with respect to time of vehicle velocity.

[0034] The vehicle jerk may include, for example, a longitudinal jerk. In other examples, the vehicle jerk may also include, for example, a lateral jerk.

[0035] The vehicle jerk is, for example, the vehicle's current speed V C and the nominal speed of the vehicle at the forward position V A is controlled based on the difference between

[0036] According to a further embodiment, the step of controlling the acceleration and / or the jerk of the vehicle comprises a step of proportionally and / or differentially controlling the acceleration and / or the jerk, and the nominal speed V of the vehicle at the forward position is controlled by the step of proportionally and / or differentially controlling the acceleration and / or the jerk of the vehicle. A is a set value in the proportional control and / or the differential control, and the current speed V of the vehicle C is the process variable of the proportional and / or derivative control.

[0037] In particular, the jerk is proportional to the vehicle's current speed V C is the nominal speed V A The speed is controlled to approach the nominal speed V A is the controller setpoint, i.e. the desired value for the vehicle speed at the forward position.

[0038] In particular, the control system includes a proportional controller, a derivative controller, and / or a proportional-derivative controller. A proportional-derivative controller (PD controller) is a combination of a proportional controller and a derivative controller, i.e., a proportional+derivative controller.

[0039] A proportional controller is a type of controller where the controller output varies proportionally to the controller input (e.g., an error signal). A derivative controller is a type of controller where the controller output varies proportionally to the time rate of change of the error signal. The error signal may be, for example, a setpoint (here, the nominal speed of the vehicle at the forward position, V A ) and the measured value of the process variable (here, the current speed of the vehicle, V C ) is the error between

[0040] According to a further embodiment, the step of implementing the curvature control function comprises: coupling a first phase of negative jerk, a second phase of zero jerk, and a third phase of positive jerk to a current velocity V of the vehicle at the current position. C , and the nominal speed V of the vehicle at the forward position. Awherein the first phase, the second phase, and the third phase are consecutive to one another.

[0041] By determining the phase of acceleration and jerk, the curvature control function can be better implemented.

[0042] The first phase is, for example, before and / or when the vehicle enters a curve in the road with negative acceleration (braking). The second phase is, for example, when driving around the curve with constant acceleration. The third phase is, for example, still with negative acceleration but with a positive jerk (still braking as before but now with reduced braking).

[0043] The first, second, and third phases (eg, the start and end times of each of the first, second, and third phases) are determined, for example, by a state machine of the control system.

[0044] In an embodiment, implementing the curvature control function includes determining a fourth phase of zero jerk and zero acceleration (i.e., constant velocity) and / or a fifth phase of positive jerk and positive acceleration, the fourth phase and the fifth phase being contiguous with the first through third phases, in particular such that the fourth phase is contiguous with the third phase and the fifth phase is contiguous with the fourth phase (or contiguous with the third phase if the fourth phase is not present).

[0045] According to a further embodiment, implementing the curvature control function comprises controlling an acceleration of the vehicle below a predefined acceleration threshold and / or controlling a jerk of the vehicle below a predefined jerk threshold.

[0046] Thus, the vehicle is controlled such that the maximum jerk (e.g. maximum longitudinal jerk) of the vehicle is limited, thus improving the safety and comfort of the driver (and other passengers).

[0047] For example, the vehicle's longitudinal jerk is controlled to be below a predetermined longitudinal jerk threshold.

[0048] According to a second aspect there is provided a computer program comprising instructions which, when executed by a computer, cause the computer to carry out the method described above.

[0049] For example the computer program means, the computer program (computer program product), may be embodied as a memory card, a USB stick, a CD-ROM, a DVD or as files downloaded from a server in a network, for example such files may be provided by sending the files constituting the computer program product over a wireless communication network.

[0050] According to a third aspect, there is provided a control system for a vehicle, the control system being configured to implement the method described above.

[0051] According to a fourth aspect, there is provided a vehicle comprising a control system as described above.

[0052] Each of the above or below entities, e.g., control system, receiving unit, first determining unit, second determining unit, third determining unit, fourth determining unit, arbitration unit, curvature control unit, PD control unit, may be realized in hardware and / or software. When realized in hardware, the entities may be embodied as a device, e.g., a computer, or as a processor, or as a part of a system, e.g., a computer system. When realized in software, the entities may be embodied as a computer program product, as a function, as a routine, as an algorithm, as a program code, as a part of a program code, or as an executable object. Furthermore, each of the above-mentioned entities may also be designed as a part of a higher-level control system of a vehicle, such as a central electronic control unit (ECU).

[0053] The embodiments and features described with reference to the method of the present invention apply mutatis mutandis to the computer program, the control system and the vehicle of the present invention.

[0054] Further possible implementations or alternative solutions of the invention also cover combinations of features (not explicitly mentioned here) described above or below with respect to the embodiments. A person skilled in the art may add separate and distinct aspects and features to the invention in its most basic form.

[0055] Further embodiments, features and advantages of the present invention will become apparent from the following description and the dependent claims.

[0056] The present invention will be described in detail below based on preferred embodiments with reference to the following drawings. [Brief description of the drawings]

[0057] [Figure 1] FIG. 1 shows a top view of a vehicle according to an embodiment. [Diagram 2] FIG. 2 shows the vehicle of FIG. 1 on a road. [Diagram 3] FIG. 3 illustrates the steering angle of the vehicle of FIG. [Figure 4] FIG. 4 is a view similar to FIG. 2, showing the road with lane markings. [Diagram 5] FIG. 5 shows data points of the determined lane base radius for the curve of the road of FIG. [Figure 6] FIG. 6 shows the time evolution of the acceleration and jerk of the vehicle of FIG. 1 when driving around a curve on the road shown in FIG. 2 or FIG. [Figure 7] FIG. 7 shows a control system for the vehicle of FIG. [Figure 8] FIG. 8 shows a flow chart illustrating a method for operating the vehicle of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] In the drawings, like reference numbers indicate similar or functionally equivalent elements unless stated otherwise.

[0059] 1 shows a schematic top view of a vehicle 1. The vehicle 1 is, for example, a passenger car. The vehicle 1 may also be another type of vehicle, such as a van or a truck. The vehicle 1 is equipped with a control system 2 for controlling the vehicle 1.

[0060] As shown in Fig. 1, the vehicle 1 is equipped with a sensor system 3 including a number of environmental sensor units 4, 5, 6, 7 arranged on the vehicle 1. The sensor system 3 in particular comprises one or more camera devices 4, for example one or more front camera devices. The camera devices 4 are configured to acquire image data I of the surroundings 8 of the vehicle 1 and to transmit the image data or image analysis results of the image data to the control system 2. The front camera device 4 is mounted on a windshield 9 of the vehicle 1.

[0061] The sensor system 3 may further comprise, for example, one or more radar devices 5 for acquiring radar data of the surroundings 8 of the vehicle 1. The sensor system 3 may further comprise, for example, one or more LIDAR devices 6 for acquiring LIDAR data of the surroundings 8 of the vehicle 1.

[0062] The sensor system 3 further comprises a steering angle sensor 10 arranged on a steering shaft 11 of the vehicle 1. The steering shaft 11 is connected to a steering wheel 12 of the vehicle 1. The steering angle sensor 10 is configured to measure a steering angle δ (FIG. 3) and a steering angular velocity W of the vehicle 1.

[0063] The sensor system 3 may comprise further sensors, such as an ultrasonic sensor 7, one or more rain sensors, and / or one or more light sensors (not shown).

[0064] 2 to 8, a method for operating the vehicle 1 will be described below. In particular, the method is a method for performing curvature control of the vehicle 1 so that the vehicle 1 smoothly enters and exits a curve 13 (FIG. 2) of a road 14.

[0065] FIG. 2 shows the vehicle 1 of FIG. 1 on a road 14 that includes a curve 13. The vehicle 1 is shown in FIG. 2 at a first position P1 (current position) before entering the curve 13. The vehicle 1 tracks its current position P1 at a current speed V c 2 is shown by a dashed line to be in a second position P2 where the vehicle 1 has entered a curve 13. The second position P2 is ahead of the first position P1 with respect to the direction of travel 15 of the vehicle 1.

[0066] In a first step S1 of the method, the control system 2 of the vehicle 1 receives sensor data S (Fig. 7) of a sensor system 3 (Fig. 1) of the vehicle 1. The sensor data S comprises odometer data of a steering angle sensor 10 (Fig. 1), in particular the current steering angle δ and the current steering angular velocity W of the vehicle 1. Furthermore, the sensor data S comprises image data I of a camera arrangement 4 (Fig. 1) of the vehicle 1. The control system 2 is for example equipped with a receiving unit 16 (Fig. 7) for receiving the sensor data S from the sensor system 3.

[0067] In a second step S2 of the method, the control system 2 determines the forward radius R of the curve 13 at the forward position P2. O based on the odometer data (δ, w). The forward position P2 is in particular a position that the vehicle 1 may reach after a given time span T (for example, 1 or 2 seconds). The control system 2 may, for example, determine the odometer-based forward radius R O The vehicle is provided with a first determination unit 20 (FIG. 7) for determining an odometer-based forward radius R O is determined based on the following relation:

[0068] Current radius R of vehicle 1 at position P1 C (Figure 3) can be expressed as follows using trigonometric functions of a right triangle. R C = L / tan(δ) Here, L is the distance between the front wheels 17 and the rear wheels 18 of the vehicle 1 (FIG. 3).

[0069] Furthermore, the current radius R c The first derivative with respect to time is given by: dR C / dt=L d / dt[1 / tan(δ)] dR C / dt=-L dδ / dt / (sin 2 (δ)]

[0070] Therefore, the odometer-based forward radius R of curve 13 at position P2 O(Figure 2) can be described as follows: R0=R C +dR C / dt R O =R C -T[(L w) / (sin 2 (δ)] where W=dδ / dt

[0071] In a third step S3 of the method, if lane markings 19 (FIG. 4) of the road 14′ on which the vehicle 1 is traveling are detected in the image data I, the control system 2 calculates a lane-based forward radius R of the curve 13′ at the forward position P2. L The control system 2 determines, for example, a lane-based forward radius R L The second determination unit 21 (FIG. 7) is provided for determining the

[0072] Furthermore, a track quality (e.g. a track quality level) of the detected lane markings 19 is determined. The track quality (e.g. a track quality level) in particular corresponds to an image quality of the image data I received by the camera arrangement 4 and / or to a detection quality of the lane markings 19 in the image data I. The track quality (e.g. a track quality level) is for example determined and / or provided by the camera arrangement 4. Alternatively or additionally, the track quality (e.g. a track quality level) can also be determined by a second determining unit 21 (FIG. 7) of the control system 2.

[0073] In a variant, the lane-based forward radius R L Error ΔR L (FIG. 5) can also be determined based on the detected lane markings 19. L may in particular be used as a measure of the track quality of the detected lane markings 19 (e.g., a measure of the track quality level).

[0074] Lane-based forward radius R L is determined by the following formula: R L =1 / [(6·a·T)+(2·b)] where a and b are third order polynomials (P(x)=ax) estimated as a fit (e.g., best fit) to the curve 13′. 3 +bx 2 +cx+d) are the first two coefficients of T. Furthermore, T is the predetermined time span of step S2.

[0075] In a first step S4 of the method, the control system 2 determines the forward radius R A Determine the forward radius R A is the odometer-based forward radius R determined in step S2 O , and the lane-based forward radius R determined in step S3 L is determined based on:

[0076] In particular, the determined odometer-based forward radius R O The lane-based forward radius R is determined as L based on a determined track quality of the detected lane markings 19 (e.g., based on a determined track quality level of the detected lane markings 19 and / or based on a lane-based forward radius R L The determined error ΔR L ), and the expected acceleration A of the vehicle 1 at the forward position P2 A The control system 2 is implemented based on, for example, the odometer-based forward radius R O and lane-based forward radius R L Based on the forward radius R A The arbitration unit 22 (FIG. 7) is provided for determining

[0077] If the determined level of track quality is below a predefined track quality threshold, the forward radius R A is the odometer-based forward radius R O is set equal to

[0078] If the determined track quality level exceeds a predefined track quality threshold and the determined expected acceleration corresponds to braking of the vehicle 1, then the forward radius R A is the lane-based forward radius R L and odometer-based forward radius R O The metric is set equal to the minimum of

[0079] If the determined level of track quality exceeds a predetermined track quality threshold and the determined expected acceleration corresponds to a positive acceleration, then a forward radius R A is the lane-based forward radius R L and odometer-based forward radius R O is set equal to the maximum of

[0080] In a variant, as shown in FIG. 5, the track quality is calculated based on the lane-based forward radius R L Error ΔR L FIG. 5 shows the lane-based forward radius R determined in a radius-location diagram. L The data point 23 is compared with the determined error ΔR L 5 shows the lane-based forward radius R L Error ΔR L In the example shown in FIG. 5, the determined error ΔR L is smaller than the predetermined threshold position Rth. However, if the visibility of the lane markings 19 (FIG. 4) is poor and / or the image quality of the image data I is low, the error ΔR L may be greater than a predetermined threshold Rth.

[0081] In the example of FIG. 5, the determined error ΔR L If is equal to or greater than a predetermined threshold Rth, the forward radius R A is the odometer-based forward radius R O is set equal to

[0082] Furthermore, in the example of FIG. 5, the determined error ΔR Lis less than a predefined threshold Rth and the determined expected acceleration corresponds to a braking of the vehicle 1, the front radius R A is the lane-based forward radius R L and odometer-based forward radius R O The metric is set equal to the minimum of

[0083] Furthermore, the determined error ΔR L is less than a predetermined threshold Rth and the determined expected acceleration corresponds to a positive acceleration, A is the lane-based forward radius R L and odometer-based forward radius R O is set equal to the maximum of

[0084] In a fifth step S5 of the method, the control system 2 determines the nominal speed V A (Figure 2) is the determined anterior radius R A and a given maximum lateral acceleration A MAX Based on this, it is determined by the following formula. V A =(A MAX ·R A ) 1 / 2

[0085] The control system 2 may, for example, determine the nominal speed V A The third determination unit 25 (FIG. 7) is provided for determining the

[0086] In a sixth step S6 of the method, the control system 2 determines the determined forward radius R of the curve 13, 13' at the forward position P2. A The determined nominal speed V corresponds to A Based on this, a curvature control function is implemented.

[0087] The control system 2 comprises, for example, a curvature control unit 26 (FIG. 7) for implementing a curvature control function. In particular, the current speed V C (Figure 2) shows the nominal speed V of vehicle 1. AThe acceleration A(t) and jerk J(t) (FIG. 6) of the vehicle 1 are controlled so that they change in an appropriate manner toward

[0088] The curvature control unit 26 includes a proportional-differential control unit 27 (PD control unit 27). A is the set value 28 of the PD control unit 27. Furthermore, the current speed V C is a process variable 29 of the PD control unit 27. The PD control unit 27, in particular, C and nominal speed V A Control is carried out based on the difference between the

[0089] The curvature control unit 26 further comprises a fourth determination unit 28 for determining the phases T1, T2, T3, T4 and T5 of the acceleration A(t) and the jerk J(t) (FIG. 6). The fourth determination unit 28 includes, for example, a state machine or other logic unit for determining the phases T1, T2, T3, T4 and T5.

[0090] The upper part of Fig. 6 shows the time evolution of the acceleration A(t) of the vehicle 1 traveling through the curve 13 (Fig. 2). Furthermore, the lower part of Fig. 6 shows the time evolution of the jerk J(t) of the vehicle 1. The jerk J(t) is the first-order derivative of the acceleration A(t) with respect to time. In other words, the jerk indicates the change in acceleration A(t) over time.

[0091] As shown in FIG. 6, a first time phase T1 of negative acceleration (braking) and negative jerk (increasing braking) is determined. The first time phase T1 corresponds, for example, to a state in which the vehicle 1 is entering and / or before entering the curve 13 (FIG. 2). Furthermore, a second time phase T2 of constant negative acceleration (constant braking) and zero jerk is determined. The second time phase T2 corresponds, for example, to a state in which the vehicle 1 is traveling in the curve 13. Furthermore, a third time phase T3 of negative acceleration (still braking) but positive jerk (decreasing braking) is determined. The third time phase T3 corresponds, for example, to a state in which the vehicle 1 is traveling in the curve 13 at a current speed V C is the nominal speed V AThe third and fourth phases T3, T4 are phases of running approaching (preparing for) zero jerk and zero acceleration (i.e., constant velocity) are also determined. The third and fourth phases T3, T4 may be referred to as "release and constant velocity phases". Furthermore, a fifth phase T5 of positive jerk and positive acceleration is determined. As shown in FIG. 5, the phases T1, T2, T3, T4 and T5 are consecutive to each other.

[0092] The curvature control unit 26 further comprises a limiting unit 29 (FIG. 7) for limiting the acceleration A and / or the jerk J (FIG. 6) of the vehicle 1. In particular, the curvature control function is activated when the acceleration A of the vehicle 1 (e.g. the absolute value of the acceleration A) exceeds a predetermined acceleration threshold A. th Furthermore, the curvature control function is implemented such that the jerk J of the vehicle 1 (e.g., the absolute value of the jerk) is less than a predetermined jerk threshold J th It is implemented so that the

[0093] Therefore, the forward radius of curvature R of the curve 13 of the road 14 on which the vehicle 1 is traveling A (Figure 2) is predicted based on the odometer data (δ, w, Figure 3) and, if lane markings 19 are detected, based on the curvature of the lane markings 19 (Figure 4). A Based on this, the nominal speed V as the desired speed at the forward position P2 A is calculated. Furthermore, the nominal speed V A In the process of achieving this, curvature control (Figure 7) is implemented to ensure that braking and positive acceleration as well as jerk are within values ​​that ensure the safety and comfort of the driver and other passengers of vehicle 1 (Figure 6).

[0094] Although the present invention has been described according to preferred embodiments, it will be apparent to one skilled in the art that modifications are possible in all embodiments. [Explanation of symbols]

[0095] 1 vehicle 2. Control System 3 Sensor System 4 Sensor Unit 5 Sensor unit 6 Sensor Unit 7 Sensor unit 8. Periphery 9. Windshield 10 Steering Angle Sensor 11 Steering shaft 12 Steering wheel 13, 13' Curve 14, 14' road 15 Travel direction 16 Receiving unit 17 wheels 18 wheels 19 Lane Markings 20 Decision Unit 21 Decision Unit 22 Arbitration Unit 23 Data points 24 Error bars 25 Decision Unit 26 Curvature Control Unit 27 PD control unit 28 Setting value 29 Process Variables δ Steering angle ΔR L error A acceleration A A acceleration A th Acceleration Threshold J Jerk J th Jerk Threshold L distance P1 Current position P2 Front position R A radius R C radius R L radius R O radius R th Radius Threshold Method steps S1~S6 T1 phase T2 phase T3 phase T4 phase T5 phase V A Velocity V C Velocity W steering angular velocity

Claims

1. A method for operating a vehicle (1), comprising: - receiving (S1) sensor data (S) of a sensor system (3) of the vehicle (1), the sensor data (S) comprising a current steering angle δ and a steering angular velocity W of the vehicle (1) traveling on a road (14) having a curve (13); a forward radius R of the curve (13) at a forward position (P2) that the vehicle (1) can reach after a given time span T; Ａ with the formula: R Ｏ = R Ｃ -T[(L・W) / (sin ２ (δ)] Ｏ where δ is the steering angle, W is the steering angular velocity, L is the distance between the front wheels (17) and the rear wheels (18) of the vehicle (1), and R Ｃ is the radius of the road (14) at the current position (P1) of the vehicle (1); and The determined forward radius R Ａ (S6) performing a curvature control function based on A method for providing the above.

2. The nominal speed V of the vehicle (1) at the forward position (P2) Ａ is the determined forward radius R Ａ and formula: V Ａ = (A ＭＡＸ ・R Ａ ) １／２ A given maximum lateral acceleration by ＭＡＸ (S5), The curvature control function is determined based on the nominal velocity V Ａ (S6), The method of claim 1.

3. The expected acceleration (A Ａ ) is the current speed V Ｃ , and the nominal speed V of the vehicle (1) at the front position (P2). Ａ is determined based on the presence of lane markings (19) on the road (14') is detected and a track quality of the detected lane markings (19) is determined based on the sensor data (S); A lane-based forward radius R of the curve (13') at the forward position (P2) Ｌ is determined based on the detected lane markings (19) (S3); If the determined track quality exceeds a predetermined track quality threshold and the determined expected acceleration corresponds to braking of the vehicle (1), the forward radius R Ａ is the lane-based forward radius R Ｌ and the forward radius R of the odometer base Ｏ In an embodiment, the curvature control function is set equal to the minimum value of the odometer-based forward radius R Ｏ and the lane-based forward radius R Ｌ (S6), If the determined track quality exceeds the predetermined track quality threshold and the determined expected acceleration corresponds to a positive acceleration of the vehicle (1), the forward radius R Ａ is the lane-based forward radius R Ｌ and the forward radius R of the odometer base Ｏ In an embodiment, the curvature control function is set equal to a maximum value of the odometer-based forward radius R Ｏ and the lane-based forward radius R Ｌ (S6), If the determined track quality is less than or equal to the predetermined track quality threshold, the forward radius R Ａ is the forward radius R of the odometer base Ｏ In an embodiment, the curvature control function is set equal to the odometer-based forward radius R Ｏ (S6), The method of claim 1.

4. The step (S6) of implementing the curvature control function is to calculate the acceleration (A) and / or jerk (J) of the vehicle (1) in relation to the current speed V of the vehicle (1) at the current position (P1). Ｃ , and the nominal speed V of the vehicle (1) at the front position (P2). Ａ Based on the above, The method of claim 1.

5. The step of controlling the acceleration (A) and / or the jerk (J) of the vehicle (1) includes a step of proportionally controlling and / or differentially controlling the acceleration (A) and / or the jerk (J), and the nominal speed V of the vehicle (1) at the forward position (P2) is Ａ is a set value (28) in the proportional control and / or differential control, and the current speed V of the vehicle (1) Ｃ is the proportional and / or derivative controlled process variable (29); The method according to claim 4.

6. The step (S6) of implementing the curvature control function includes: calculating a first phase (T1) of a negative jerk (J), a second phase (T2) of a zero jerk (J) and a third phase (T3) of a positive jerk (J) in relation to a current velocity V of the vehicle (1) at a current position (P1); Ｃ , and the nominal speed V of the vehicle (1) at the front position (P2). Ａ wherein the first time phase (T1), the second time phase (T2), and the third time phase (T3) are consecutive in this order; The method of claim 1.

7. The step (S6) of implementing the curvature control function includes: determining an acceleration (A) of the vehicle (1) based on a predetermined acceleration threshold (A ｔｈ ) and / or controlling the jerk (J) of the vehicle (1) to less than a predetermined jerk threshold (J ｔｈ ) or less, The method of claim 1.

8. A computer program comprising instructions which, when executed by a computer, cause the computer to carry out the method of claim 1.

9. A control system (2) for a vehicle (1), configured to implement the method according to claim 1.

10. A vehicle (1) comprising a control system (2) according to claim 9.

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