Method and system for determining a distance between two vehicles

Abstract

The invention relates to a method and a system for determining a distance between two vehicles. The method uses data processing units, each with a transmitting unit and three receiving units assigned to the vehicles. Distance differences are calculated based on the propagation time differences of a transmitted radio wave received by the receiving units. Using triangulation, the position of the transmitting unit is determined from this, allowing the relative position of the two data processing units to be determined, and thus the distance between the vehicles. The system enables precise and reliable distance measurement without external infrastructure and is particularly suitable for applications in the field of automated driving functions, convoy driving, or driver assistance systems.

Description

Technical area

[0001] The invention relates to a method and a system for determining a distance between two vehicles, in particular motor vehicles, which are moving in the same direction of movement.

[0002] For this purpose, each of the two vehicles is assigned a data processing unit, each comprising a transmitting unit and three receiving units, with the positions of the receiving units relative to a reference point being known. The distance between the vehicles is calculated, in particular, by determining the propagation time differences of a transmitted radio wave and subsequent triangulation. background

[0003] Determining the distance between two vehicles is of great importance in various technical areas, in particular for improving road safety, for driver assistance systems or for optimising vehicle movements in a convoy or for automated driving functions.

[0004] Known distance measurement methods typically rely on GPS data, radar, or lidar technologies. For example, a vehicle's position is determined using satellite signals, or the distance to a vehicle ahead is measured using radar signals. However, these methods have limitations in terms of accuracy, availability (e.g., in tunnels or densely built-up urban areas), as well as technical complexity and cost.

[0005] Radio-based communication systems such as V2V (vehicle-to-vehicle) are also known, in which vehicles exchange information about their position, speed, or direction of travel. However, these systems primarily serve communication rather than precise distance determination using physical signals. Disclosure of the invention

[0006] The object of the invention was therefore to eliminate the disadvantages of the prior art and in particular to provide a simple, cost-effective and yet precise method and a corresponding system for determining the distance between two vehicles.

[0007] The object of the invention is achieved by the features of the independent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0008] In a preferred embodiment, the invention relates to a method for determining a distance between two vehicles, - wherein a first vehicle is set in motion by a first person and a second vehicle is set in motion by a second person in the same direction of movement; - wherein a first data processing unit is assigned to the first vehicle and a second data processing unit is assigned to the second vehicle, wherein each of the data processing units comprises a transmitting unit and three receiving units, the positions of which are known relative to a reference point; comprising the following method steps: - the transmitting unit of the first data processing unit transmits a radio wave which is detected by the three receiving units of the second data processing unit; - the second data processing unit determines the propagation time differences of the radio wave to the various receiving units; - the second data processing unit uses the propagation time differences to determine a distance difference between the respective receiving units of the second data processing unit and the transmitting unit of the first data processing unit; - based on the determined distance differences between the respective receiving units of the second data processing unit and the transmitting unit of the first data processing unit, the second data processing unit uses the triangulation method to determine a position of the transmitting unit of the first data processing unit, whereby the relative positions of the first and second data processing units to one another and thus the distance between the first vehicle and the second vehicle can be determined.

[0009] One advantage of the proposed method is that it provides an accurate and reliable method for determining the distance between two vehicles. By using data processing units, each with a transmitter and multiple receiver units, and evaluating the data using triangulation, the relative position of the vehicles can be precisely determined. This enables precise distance detection, particularly in dynamic driving situations—such as convoy driving, driver assistance systems, or automated vehicle applications—and thus improves safety, efficiency, and coordination in road traffic.

[0010] A similar direction of motion preferably means that both objects (in this case, the two vehicles) are moving in the same direction. This means that, considering the motion of the vehicles, they are essentially moving parallel to each other in the same direction. If the directions of motion of the two vehicles were different, they would either be moving away from each other or moving toward each other.

[0011] A data processing unit is preferably an electronic unit that serves to acquire, process, and transmit data. A data processing unit preferably comprises various components, such as a microcontroller, a processor, a memory, various sensors, actuators, and communication devices. Within the meaning of the invention, two data processing units are preferably provided, wherein a first data processing unit is assigned to a first vehicle and a second data processing unit is assigned to a second vehicle. Assignment can mean, for example, that the data processing unit is mounted on the vehicle. Particularly preferably, a data processing unit further comprises a transmitting unit and at least three receiving units.

[0012] In a preferred embodiment, the transmitting unit emits a radio wave that is detected by the receiving units. The transmitting unit preferably comprises a transmitter and an antenna that work together to transmit the radio signal. The transmitter can use different frequencies and transmission methods depending on the requirements of the specific application. In this case, the signal will preferably be in the GHz range, which means it is a wireless high-frequency communication.

[0013] Furthermore, a receiving unit preferably comprises an antenna that receives the radio signal and a receiver that amplifies and demodulates the signal. The receiving units of a data processing unit are preferably arranged such that their relative positions to one another and their (absolute) positions with respect to a reference point are known. This allows the data processing unit to measure the propagation time differences of a radio signal to the various receiving units.

[0014] In a further preferred embodiment, the data processing unit comprises a housing. Within this housing, the receiving units and the transmitting unit are arranged at known positions relative to a reference, in particular a reference point, within the housing. This allows the distances and relative positions of the receiving units to each other and to the reference point to be determined and are thus known. Particularly preferably, the reference point within the housing is the origin of a virtual coordinate system, which serves as the basis for determining a distance between a first and second data processing unit.

[0015] A radio wave is preferably an electromagnetic wave used to transmit information through air or free space. Radio waves have a specific frequency and wavelength and can be transmitted and received by antennas. For the proposed method, radio waves with a frequency of 1 kHz to 30 GHz are preferably used. Frequencies in the range of 1-10 GHz are particularly preferred, as they offer sufficient range and accuracy. Radio waves can be selected from, for example, Bluetooth, UWB, Wi-Fi, Zigbee, RFID, radio waves (FM, AM), radar waves, or ultrasonic waves.

[0016] The method according to the invention preferably uses the "Time Difference of Arrival" (TDOA) method for determining position based on propagation time differences. With TDOA, the propagation time differences are preferably measured between multiple receivers and a single signal source. Based on the propagation time differences, a difference in the distances of the respective receiving units from the signal source can be determined. The propagation time differences can be measured either directly or indirectly calculated by comparing the signal propagation time between the receivers. The difference in the distances is determined by multiplying the propagation time difference by the propagation speed.

[0017] Triangulation enables precise positioning and is a fundamental method in cartography and location determination. At least two known points and one unknown point are used to calculate its position. The calculations are based on the principles of trigonometry, allowing precise spatial coordinates to be determined. In this case, the coordinates of the three receiving units in the respective data processing units are known, while the transmitting unit of the respective other data processing unit is unknown. The preferred application of triangulation in the context of the present invention is described with reference to Fig. 3 explained below.

[0018] In a preferred embodiment, the radio wave is transmitted at predefined time intervals to enable continuous or periodic updates of the relative positions of the vehicles. This enables continuous monitoring of the positions, which can lead to timely and dynamic adjustment of the driving strategy or can also be used for subsequent analyses and evaluations.

[0019] In a preferred embodiment, visual, acoustic, or haptic feedback regarding a relative position and / or distance is provided to the occupants of a vehicle. It is understood that the data processing unit has provided appropriate means for this purpose, such as a display, an LED indicator, a loudspeaker, headphone interfaces, or vibration motors.

[0020] In another preferred embodiment, the acquired data is transmitted wirelessly to an external device, such as a smartphone or computer, to enable detailed analysis and visualization. The wireless transmission of acquired data to an external device enables comprehensive analysis and long-term monitoring.

[0021] In another preferred embodiment, additional sensors such as GPS, accelerometers, or gyroscopes are integrated into the data processing units to further refine the positioning. The integration of additional sensors such as GPS, accelerometers, or gyroscopes improves the accuracy of positioning, particularly under difficult environmental conditions or in the presence of signal interference. The combination of various sensor data enables a more comprehensive analysis of driving performance.

[0022] In a further preferred embodiment, the invention relates to a system for determining a distance between two vehicles, comprising: - a first vehicle and a second vehicle movable in the same direction of movement; - a first data processing unit associated with the first vehicle and a second data processing unit associated with the second vehicle, each data processing unit comprising a transmitting unit and three receiving units, and the positions of the respective three receiving units relative to a reference point are known; - means for determining propagation time differences of a radio wave emitted by the transmitting unit of the first data processing unit to the various receiving units of the second data processing unit; - means for determining distance differences between the respective receiving units of the second data processing unit and the transmitting unit of the first data processing unit via the propagation time differences; - means for determining the position of the transmitting unit of the first data processing unit by triangulation based on the determined distance differences, whereby the relative positions of the first and second data processing units to one another can be determined; - Means for determining the position of the transmitting unit of the first data processing unit by triangulation based on the determined distance differences, whereby the relative position of the first data processing unit to the second data processing unit can be determined and from this the distance between the first vehicle and the second vehicle can be determined.

[0023] The system enables precise determination of the distance between two vehicles, which is particularly important for safety-relevant applications, coordinated driving maneuvers, or the control of vehicle convoys. By using triangulation to determine the relative positions of the data processing units, a high degree of accuracy in distance determination is achieved.

[0024] A person skilled in the art will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method according to the invention apply analogously to the system according to the invention for determining a distance between two vehicles.

[0025] Further embodiments are explained in more detail below with reference to the accompanying drawings. The composite floor panel according to the invention is not intended to be limited solely to these listed embodiments. Rather, embodiments are also envisaged that are now and in the future equally accessible to the skilled person using other technical means. Short description of the drawing Fig. 1 shows the method step of transmitting a radio wave from the transmitting unit of the first data processing unit, wherein the radio wave is detected by the receiving units of the second data processing unit at three different times Fig. 2 shows the method step of transmitting a radio wave from the transmitting unit of the first data processing unit, Fig. 3 demonstrates the use of the triangulation method in the preferred method Preferred embodiments

[0026] Fig. Figure 1 schematically shows two data processing units 9, 11, each assigned to a vehicle 1, 3. These are set in motion in the same direction of movement 17.

[0027] Both the first and the second data processing units 9, 11 preferably comprise a housing 25, a transmitting unit 13 and three receiving units 15. Furthermore, a reference point 23 is preferably provided in the housing 25, which acts as the origin for a (virtual) coordinate system.

[0028] The transmitting unit 13 of the first data processing unit 9 emits a radio wave 19. This is detected at time t1 by a first receiving unit 15, at time t2 by a second receiving unit 15, and at time t3 by a third receiving unit 15. By detecting the times of the radio wave 19 at the individual receiving units 15, the propagation time differences (Δt 13 , Δt12 , Δt 23 ) can be determined. Thus: Δt13=t1−t3 Δt12=t1−t2 Δt23=t2−t3

[0029] Fig. Figure 2 shows schematically the distance differences (Δd 13 , Δd 12 , Δd 23 ), which is calculated using the runtime differences (Δt 13 , Δt 12 , Δt 23 ) can be determined. The individual components of the data processing units 9, 11 are already in Fig. 1 has been discussed.

[0030] Based on the propagation speed of the radio wave in air (c Luft ) the individual distance differences are calculated as follows: Δt13×cAir=Δd13 Δt12×cAir=Δd12 Δt23×cAir=Δd23

[0031] Fig.Figure 3 demonstrates the use of the triangulation method in the preferred method. It is assumed that the position of the transmitting unit 13 of a first data processing unit 9 corresponds to an intersection point formed by the three circles drawn around the three receiving units 15 of a second data processing unit 11. The radius of the circles corresponds to the distance d1, d2, and d3 of the three receiving units 15 of the second data processing unit 11 from the transmitting unit 13 of the first data processing unit 9.

[0032] The distance between two points in three-dimensional space can generally be calculated using the Pythagorean theorem: d1=(x1−x)2+(y1−y)2+(z1−z)2 d2=(x2−x)2+(y2−y)2+(z2−z)2 d3=(x3−x)2+(y3−y)2+(z3−z)2

[0033] Here, x, y, and z represent the coordinates of the transmitting unit 13 of the first data processing unit 9, whereas (x1, y1, z1), (x2, y2, z2) and (x3, y3, z3) correspond to the coordinates of the three receiving units 15 of the second data processing unit 11, which are known as already discussed.

[0034] Using the previously determined distance differences Δd 13 , Δd 12 , and Δd 23 and the known positions of the receiving units 15 of the second data processing unit 11, the position of the transmitting unit 13 of the first data processing unit 9 can be determined by solving a system of non-linear equations: Δd13=(x1−x)2+(y1−y)2+(z1−z)2−(x3−x)2+(y3−y)2+(z3−z)2=Δt13×cAir Δd12=(x1−x)2+(y1−y)2+(z1−z)2−(x2−x)2+(y2−y)2+(z2−z)2=Δt12×cAir Δd23=(x2−x)2+(y2−y)2+(z2−z)2−(x3−x)2+(y3−y)2+(z3−z)2=Δt23×cAir

[0035] The position or coordinates (x, y, z) of the transmitting unit 13 of the first data processing unit 9 obtained by solving the non-linear equations refer to the reference point 23 of the second data processing unit 11 (or the coordinate system derived therefrom).

[0036] It is understood that this can be used to determine whether the first data processing unit or the first vehicle is located in front of or behind the second data processing unit or the second vehicle in the direction of movement, as well as their relative positions. The distance between the two vehicles can thus be determined from the determined relative positions of the two data processing units. LIST OF REFERENCE SYMBOLS 1 First vehicle 3 Second vehicle 9 First data processing unit 11 Second data processing unit 13 Transmitter unit 15 Receiving unit 17 Direction of movement 19 radio wave 21 System 23 Reference point inside the housing 25 housings d1 Distance between a first receiving unit of the second data processing unit and a transmitting unit of the first data processing unit d2 Distance between a second receiving unit of the second data processing unit and a transmitting unit of the first data processing unit d3 Distance between a third receiving unit of the second data processing unit and a transmitting unit of the first data processing unit Δd 13 Distance difference d1 - d3 Δd 12 Distance difference d1 - d2 Δd 23 Distance difference d2 - d3

Claims

[1] Method for determining a distance between two vehicles (1, 3), wherein a first vehicle (1) and a second vehicle (3) are set in motion in the same direction of movement; wherein the first vehicle (1) is assigned a first data processing unit (9) and the second vehicle (3) is assigned a second data processing unit (11), each comprising a transmitting unit (13) and three receiving units (15), the positions of the respective three receiving units (15) being known with respect to a reference point (23); comprising the following procedural steps: - the transmitting unit (13) of the first data processing unit (9) transmits a radio wave (19) which is detected by the three receiving units (15) of the second data processing unit (11); - the second data processing unit (11) determines propagation time differences of the radio wave (19) to the various receiving units (15); - the second data processing unit (11) determines a distance difference (Δd 12 , Δd 23 , Δd 13 ) of the respective receiving units (15) of the second data processing unit (11) to the transmitting unit (13) of the first data processing unit (9); - based on the determined distance differences (Δd 12 , Δd 23 , Δd 13 ) between the respective receiving units (15) of the second data processing unit (11) and the transmitting unit (13) of the first data processing unit (9), a position of the transmitting unit (13) of the first data processing unit (9) is determined by the second data processing unit (11) using the triangulation method, whereby the relative positions of the first and second data processing units (9, 11) to one another and thus the distance between the first vehicle (1) and the second vehicle (3) can be determined. [2] The method of claim 1, wherein visual, acoustic or haptic feedback about a relative position or distance is given to vehicle occupants. [3] Method according to one of the preceding claims, wherein additional sensors such as GPS, accelerometers or gyroscopes are integrated into the data processing units (9, 11) to further refine the position determination. [4] System for determining a distance between two vehicles (1, 3), comprising: - a first vehicle (1) and a second vehicle (3) which are movable in the same direction of movement; - a first data processing unit (9) assigned to the first vehicle (1) and a second data processing unit (11) assigned to the second vehicle (3), each data processing unit (9, 11) comprising one transmitting unit (13) and three receiving units (15) and the positions of the respective three receiving units relative to a reference point (23) being known; - means for determining propagation time differences of a radio wave (19) emitted by the transmitting unit (13) of the first data processing unit (9) to the various receiving units (15) of the second data processing unit (11); - Means for determining distance differences (Δd 12 , Δd 23 , Δd 13 ) the respective receiving units (15) of the second data processing unit (11) to the transmitting unit (13) of the first data processing unit (9) via the propagation time differences; - means for determining the position of the transmitting unit (13) of the first data processing unit (9) by triangulation based on the determined distance differences (Δd 12 , Δd 23 , Δd 13 ), whereby the relative position of the first data processing unit (9) to the second data processing unit (11) can be determined and from this the distance between the first vehicle (1) and the second vehicle (3) can be determined.

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