Method for determining the sideslip angle of a vehicle and detection system

Abstract

The invention relates to a method for determining a vehicle's sideslip angle (α) by means of an optical sensor (12) by means of which light reflected from the road surface is detected and evaluated, comprising the method steps: - Detecting the longitudinal speed of the vehicle using the optical sensor (12); - Detecting the lateral speed of the vehicle using the optical sensor (12); and - Combining the longitudinal and lateral speeds to calculate the vehicle's sideslip angle (α). The optical sensor (12) is adjusted by means of a rotary mechanism (16) in a defined movement relative to the vehicle to simultaneously and partially detect the longitudinal and lateral speeds. Furthermore, the invention relates to a detection system (10) for determining such a sideslip angle (α).

Description

[0001] The invention relates to a method for determining the sideslip angle of a vehicle according to the preamble of claim 1. The invention further relates to a detection system.

[0002] German patent DE 10 2008 038 642 A1 discloses a vehicle dynamics control system based on the detection of a vehicle's longitudinal and lateral speeds to calculate the sideslip angle and stabilize the vehicle in critical driving situations. This system uses an electronic processing unit that controls interventions for vehicle stabilization based on speed data and other vehicle-specific measurements.

[0003] The object of the invention is to improve a method for detecting and determining the sideslip angle in order to increase the safety of the vehicle.

[0004] This problem is solved by means of a method with the features of claim 1 and by means of a detection system according to the invention. Advantageous embodiments of the detection system according to the invention are to be regarded as advantageous embodiments of the method according to the invention, wherein the means of the detection system are used to carry out the method steps. Furthermore, advantageous developments of the invention are described by the dependent claims, the following description, and the figures.

[0005] One aspect of the invention relates to a method for determining the sideslip angle of a vehicle, particularly a passenger car, which is designed to perform the detection and calculation of this sideslip angle more accurately, especially to improve the vehicle's stability and safety. The sideslip angle indicates how much the vehicle deviates from the intended driving line, particularly in critical driving situations such as cornering. To carry out this method, a sensor device, in particular an optical sensor, is used that detects light reflected from the road surface. The optical sensor is designed to detect motion data of the vehicle, in particular the longitudinal and lateral speeds.These two speeds are necessary for calculating the sideslip angle, since the sideslip angle describes the difference between the direction of movement of the vehicle and its longitudinal axis.

[0006] The process involves measuring the vehicle's longitudinal speed using an optical sensor that measures the vehicle's forward movement along its longitudinal axis. This measurement is necessary to determine the vehicle's speed in the direction of travel / longitudinal direction. Additionally, the optical sensor measures the lateral speed, which occurs when the vehicle is moved laterally, for example, by cornering. This lateral movement is also necessary for calculating the sideslip angle, as the measured longitudinal and lateral speed values ​​are ultimately combined in an electronic processing unit to calculate the vehicle's sideslip angle.

[0007] In other words, the sideslip angle indicates how much the vehicle deviates from its original direction of travel, which can indicate potential instability. By capturing and processing longitudinal and lateral speeds, the sideslip angle can be determined with high accuracy using algorithms and software. This allows for real-time monitoring of the vehicle's behavior and early intervention to stabilize the vehicle by at least partially controlling coupled control systems, such as initiating braking interventions or reducing speed to prevent the vehicle from skidding. Accurate determination of the sideslip angle thus contributes significantly to improving vehicle safety, especially under critical driving conditions.

[0008] To solve the problem of the invention, it is provided that the optical sensor is imparted with a defined movement relative to the vehicle by means of a rotary mechanism. This movement is carried out as an oscillating circular motion with a predetermined amplitude and frequency for the simultaneous and partial detection of longitudinal and lateral speeds. This allows the sensor to scan a larger area of ​​the roadway, resulting in improved detection of the motion data and thus solving the problem of the invention.

[0009] The rotating arrangement of the sensor also offers technical advantages, as the movement allows the sensor to capture vehicle dynamics in multiple directions. This oscillating motion also reduces measurement errors, since the sensor positions are continuously adjusted, thus enabling more accurate data acquisition. Furthermore, the rotating mechanism better counteracts or compensates for disturbances and, for example, the vehicle's own movement, resulting in more stable and precise measurements.

[0010] In an advantageous embodiment of the invention, it is provided that the disturbance generated by the intrinsic movement of the optical sensor is subtracted from the measurement signal in order to improve the accuracy in determining the vehicle speed and the sideslip angle.

[0011] In an advantageous embodiment of the invention, angular velocities and accelerations are additionally recorded at a fixed measuring point on the vehicle and taken into account as a second known disturbance variable when determining the sideslip angle. This helps to better compensate for influences caused by dynamic movements of the vehicle.

[0012] In an advantageous embodiment of the invention, it is provided that the intrinsic movement of the optical sensor is periodically adjusted in order to be able to react to changing driving conditions or other external influences.

[0013] In an advantageous embodiment of the invention, the determined sideslip angle values ​​are compared with speed data from other sensor systems, such as wheel speed sensors or GPS data. This enables the verification of the measured values ​​and helps to detect deviations at an early stage, thereby further increasing the measurement accuracy.

[0014] Another aspect of the invention relates to a detection system for determining a vehicle's sideslip angle, comprising an optical sensor designed to detect light reflected from the road surface and to measure both the longitudinal and lateral speeds of the vehicle. Furthermore, the detection system includes an electronic computing unit designed to process the detected longitudinal and lateral speed values ​​and calculate the vehicle's sideslip angle from them. According to the invention, the optical sensor is rotatable around an axis by means of a rotary mechanism in a defined movement relative to the vehicle, enabling the simultaneous and partial detection of the longitudinal and lateral speeds.

[0015] In other words, the algorithm for determining the current sideslip angle is based on a mechanically induced rotation of the sensor head, which is executed as an oscillating circular motion and simultaneously recorded. This allows the sensor's intrinsic motion relative to the vehicle to be known. This intrinsic motion is subtracted from the measurement signal to obtain the absolute measurement signal resulting from the actual vehicle movement. Additionally, angular velocities and accelerations are recorded at a fixed measuring point on the vehicle to account for the second known disturbance caused by pitching and rolling of the vehicle body. This integrates the vehicle's intrinsic motion into the calculation, enabling a more accurate determination of the sideslip angle.

[0016] In summary, a measurement method and design of an improved vectorial speed sensor is proposed, in particular for determining the sideslip angle during the operation of the vehicle / motor vehicle.

[0017] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0018] This shows: Fig. 1. A pictorial diagram illustrating a method for determining the sideslip angle of a vehicle using a detection system; and Fig. 2. Another diagram illustrating a side view of an arrangement of the detection system with an optical sensor relative to a roadway, to further illustrate the method for determining the vehicle's sideslip angle.

[0019] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0020] Fig. Figure 1 shows a diagram illustrating a method for determining the sideslip angle α of a vehicle using a detection system 10. The detection system 10 comprises an optical sensor 12 directed at the road surface 14. The sensor 12 detects reflected light from the road surface 14 and measures the vehicle's motion data. The sensor's rotary mechanism 16 enables an oscillating circular motion 18, which sets the sensor into a defined self-movement relative to the vehicle. This movement occurs with a predetermined amplitude and frequency to at least partially improve or stabilize, and in particular optimize, the measurement of the vehicle speeds.

[0021] In the Fig. Figure 1 shows the resulting velocity vector v, which depicts the overall motion of the vehicle. The vector v_x represents the longitudinal velocity along the vehicle's axis, and the vector v_y represents the lateral velocity, which occurs during sideways movements of the vehicle. Both velocity vectors v_x and v_y are detected by sensor 12 and transmitted to an electronic computing unit to calculate the vehicle's sideslip angle α.

[0022] The sideslip angle α is represented as the angle between the longitudinal velocity vector v_x and the resulting velocity vector v. This angle α indicates how much the vehicle drifts laterally, i.e., how much it travels at a different angle to the longitudinal axis than its actual direction of travel. The oscillating circular motion 18 of the sensor, enabled by the rotary mechanism 16, simultaneously records the longitudinal and lateral velocities, vectors v_x and v_y. The measurement uncertainties arising from this motion, which are considered the first disturbance variables, are subtracted from the recorded signals. Additionally, sensors permanently installed on the vehicle, which measure angular velocities and accelerations, can be recorded as second disturbance variables to further refine the calculation of the sideslip angle α and to compensate for dynamic influences such as roll and pitch movements.

[0023] In other words, the first disturbance generated by the intrinsic movement of the optical sensor 12 is subtracted from the measurement signal to improve the accuracy of the measurements. Additionally, angular velocities and accelerations are recorded at a vehicle-fixed measuring point; these are incorporated as a second known disturbance variable into the calculation of the sideslip angle α. The intrinsic movement of the sensor 12 is periodically adjusted to respond to changing driving conditions, and the determined sideslip angle values ​​are compared with additional velocity data from other sensor systems to further increase the measurement accuracy.

[0024] Fig. Figure 2 shows another diagram illustrating the side view of an arrangement of the detection system 10 with an optical sensor 12 relative to the roadway 14. This illustration serves to further demonstrate the method for determining the vehicle's sideslip angle α.

[0025] This view shows the measurement height 20 in the vehicle's vertical direction z, which describes the distance of the optical sensor 12 from the road surface 14. The optical sensor 12 is positioned at a defined height 20 to capture the light reflected from the road surface 14 according to specifications, thus enabling accurate measurements of the vehicle's longitudinal and lateral speeds.

[0026] In summary, the optical sensor is designed to acquire 12 measurement signals, which are corrected by an oscillating circular motion to subtract disturbances caused by the vehicle's own motion. Subsequently, the vehicle's own motions, such as angular velocities and accelerations, are recorded and used to fuse the data. This corrected data ultimately leads to the determination of the sideslip angle α, which is then output as a value to monitor the vehicle's handling in real time.

[0027] The invention thus proposes a measuring method and construction of an improved vectorial speed sensor for determining the sideslip angle during driving operation. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2008 038 642 A1

[0002]

Images