A TTC prompt system and method based on dynamic tactile interaction

Abstract

The present invention discloses a TTC prompt system based on dynamic tactile interaction, comprising: an environmental perception module, which collects dynamic information of surrounding traffic participating vehicles in real time; a collision prediction module, which receives the dynamic information and predicts the time to collision (TTC) based on the dynamic information and the motion state of the vehicle, and generates collision warning information based on the TTC value; a dynamic tactile warning module, which includes multiple vibration units, each corresponding to a different orientation; the dynamic tactile warning module receives the collision warning information and activates the vibration unit in the corresponding orientation according to the orientation of the collision risk corresponding to the collision warning information, causing the vibration unit to vibrate. The present invention also discloses a TTC prompt method based on dynamic tactile interaction, which provides a more intuitive and efficient collision warning method, ensuring that the driver can obtain the most spatially aware warning in the shortest time, optimizing the driver's reaction time, and improving road safety.

Description

Technical Field

[0001] The present invention belongs to the technical field of traffic safety, and in particular relates to a TTC prompting system and method based on dynamic tactile interaction. Background Art

[0002] With the rapid development of new energy vehicle technology, vehicle intelligence continues to increase, and autonomous driving technology is gradually maturing. In particular, driven by Level 3 and above autonomous driving technologies, driver assistance systems, vehicle perception, and decision-making capabilities are continuously improving, leading to a gradual decrease in driver involvement. However, despite the convenience brought by intelligent driving, safety remains a core concern for users and businesses. Ensuring rapid response and handling of unexpected traffic conditions during autonomous driving has become a key factor in improving the performance of intelligent driving systems.

[0003] As smart cockpit technology evolves, achieving efficient and comfortable in-car human-machine interaction while ensuring driver safety has become a key industry trend. Traditional voice and visual interaction methods are gradually expanding to tactile interaction. Tactile feedback, as a direct and immediate method of feedback, can enhance the driver's perception of the environment and improve the driving experience, especially in complex environments. Among various interaction methods, tactile interaction is becoming a key focus in smart cockpit research and development due to its efficiency, intuitiveness, and real-time nature.

[0004] TTC (Time to Collision) refers to the estimated time before a collision occurs between a vehicle and surrounding traffic participants. Real-time TTC monitoring and calculation can effectively provide early warning of potential collisions. As part of Advanced Driver Assistance Systems (ADAS), TTC prediction technology provides drivers with advance warnings, enabling them to make timely evasive decisions. Summary of the Invention

[0005] One object of the present invention is to provide a TTC prompt system based on dynamic tactile interaction, which can dynamically activate the corresponding vibration unit according to the direction of the collision and provide the driver with a warning with spatial perception.

[0006] Another object of the present invention is to provide a TTC prompt method based on dynamic tactile interaction, which can provide the driver with efficient and intuitive warning information by combining dynamic tactile interaction with collision time prediction.

[0007] The technical solution provided by the present invention is:

[0008] A TTC prompt system based on dynamic tactile interaction, comprising:

[0009] Environmental perception module, which collects dynamic information of surrounding traffic vehicles in real time;

[0010] a collision prediction module, which receives the dynamic information, predicts a time to collision (TTC) based on the dynamic information and the motion state of the vehicle, and generates collision warning information based on the TTC value;

[0011] A dynamic tactile warning module includes multiple vibration units, each of which corresponds to a different orientation. The dynamic tactile warning module receives the collision warning information and activates the vibration unit in the corresponding orientation according to the orientation of the collision risk corresponding to the collision warning information, causing the vibration unit to vibrate.

[0012] Preferably, the plurality of vibration units are arranged in the seat cushion of the driver's seat according to corresponding orientations.

[0013] A TTC prompting method based on dynamic tactile interaction includes the following steps:

[0014] Step 1: Obtain dynamic information of surrounding traffic participating vehicles, including: location coordinates of traffic participating vehicles, boundary coordinate sets, and heading angles, speeds, and accelerations of traffic participating vehicles;

[0015] Step 2: Calculating the collision time between the ego vehicle and each participating vehicle based on the dynamic information and the ego vehicle's motion state, and comparing the collision time with a set collision time threshold; if the collision time is equal to or lower than the collision time threshold, determining that there is a collision risk;

[0016] Step 3: Determine the position of the traffic vehicle with collision risk relative to the vehicle, and transmit the position information to the dynamic tactile warning module; the dynamic tactile warning module activates the vibration unit corresponding to the position information and transmits a warning signal to the driver.

[0017] Preferably, in the step three, the method further comprises: adjusting the vibration intensity and vibration frequency of the vibration unit according to the collision time;

[0018] Among them, the shorter the collision time, the greater the vibration intensity of the corresponding vibration unit and the higher the vibration frequency.

[0019] Preferably, when TTC=TTC * When the vibration intensity of the vibration unit is: ε=50%ε max ;

[0020] When 1s<TTC<TTC * When , the vibration intensity of the vibration unit is:

[0021]

[0022] When TTC≤1s, the vibration intensity of the vibration unit is: ε=ε max ;

[0023] Among them, ε max is the maximum vibration intensity of the vibration unit, TTC is the collision time, TTC * is the collision time threshold.

[0024] Preferably, in step 1, the boundary coordinate set of the traffic participating vehicles is expressed as:

[0025] P(t)={(x1(t),y1(t)),(x2(t),y2(t)),...,(x n (t),y n (t))};

[0026] Among them, (x1(t),y1(t)), (x2(t),y2(t)), (x n (t),y n (t)) represent the coordinates of boundary point 1, boundary point 2, and boundary point n of the traffic participating vehicle at time t in the vehicle coordinate system; the value of n is: n≥4.

[0027] Preferably, in step 2, the method for calculating the collision time between the vehicle and the participating vehicles is:

[0028] According to the set collision prediction step, the boundary coordinates of the vehicle and the boundary coordinates of the participating vehicles at each moment after the current moment are predicted and calculated respectively; if t k If any boundary point of the traffic participating vehicles at the moment is located inside the space-time polygon composed of the boundary coordinate set of the vehicle, then it is judged that t k The time is the collision time; the difference between the collision time and the current time is the collision time.

[0029] Preferably, it is determined that k The method to determine whether the boundary point i of the traffic participating vehicle A is located inside the space-time polygon composed of the vehicle boundary coordinate set is:

[0030] Calculate t separately k The angle between the line connecting the boundary point i of the traffic participating vehicle A and each boundary point of the ego vehicle and the positive direction of the x-axis of the ego vehicle coordinate system is:

[0031] Among them, t k The angle between the line connecting the boundary point i of the traffic participant vehicle A and the boundary point j of the ego vehicle and the positive direction of the x-axis of the ego vehicle coordinate system is:

[0032] β j =atan2(y egoj (t k )-y Ai (t k ),xegoj (t k )-x Ai (t k ));

[0033] Among them, x egoj (t k ),y egoj (t k ) is t k The horizontal and vertical coordinates of the vehicle boundary point j at the moment, x Ai (t), y Ai (t) are t k The horizontal and vertical coordinates of the boundary point i of vehicle A at the moment of traffic.

[0034] Among them, atan2(y,x) is the inverse tangent function, which calculates the angle between the line connecting the point (x,y) and the origin and the positive direction of the x-axis.

[0035] Sum all included angles:

[0036]

[0037] If t k The sum of all angles at the moment Θ sum =±2π, then the boundary point i of the traffic participating vehicle A is inside the space-time polygon composed of the vehicle boundary coordinate set; m represents the number of vehicle boundary points.

[0038] Preferably, the collision time threshold is set to 2s.

[0039] Preferably, the collision prediction step is set to 0.1s.

[0040] The beneficial effects of the present invention are:

[0041] Improve driving safety: By combining dynamic tactile interaction with TTC prediction technology, the present invention can predict the collision time between the vehicle and surrounding traffic vehicles in real time, and transmit warning information to the driver with intuitive, spatially located tactile signals, thereby significantly improving the driver's perception of potential collision risks and effectively reducing the incidence of traffic accidents.

[0042] Real-time and accuracy: The present invention utilizes the environmental perception module to collect real-time data such as the location, speed, acceleration, and heading angle of surrounding traffic vehicles, and adopts advanced TTC calculation methods through the collision prediction module to quickly determine the risk of collision. The dynamic tactile warning module dynamically adjusts the vibration intensity and feedback direction in real time according to the signal, ensuring that the warning information is accurately and timely transmitted, thereby improving the driver's response efficiency.

[0043] Environmental adaptability and stability: Compared with traditional visual and auditory warning methods, the tactile feedback system of the present invention is not affected by external environmental factors such as light and noise, and can operate stably under various complex driving conditions, ensuring that it can still provide reliable collision warnings to the driver in harsh environments.

[0044] Intuitive and non-intrusive: Dynamic tactile interaction allows drivers to intuitively perceive potential hazards from different directions, while avoiding distractions or interference caused by visual or auditory cues. This helps drivers maintain continuous attention on road conditions and enhances the overall driving experience.

[0045] Modular design and convenient integration: The present invention adopts a modular structural design, and information is transmitted between modules through standard interfaces, which facilitates integration with existing smart cockpits, vehicle networks and driver assistance systems, while providing a technical foundation and flexibility for subsequent function expansion and system optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a block diagram of the overall structure of the TTC prediction system based on dynamic tactile interaction described in the present invention.

[0047] Figure 2 This is a schematic diagram of a scenario in Example 1 of the present invention.

[0048] Figure 3 Flowchart of the TTC prediction method based on dynamic tactile interaction according to the present invention.

[0049] Figure 4 Schematic top view of the arrangement of the vibration unit in the driver's seat cushion area of ​​the dynamic tactile warning module in Example 1 of the present invention. DETAILED DESCRIPTION

[0050] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0051] like Figure 1As shown, the present invention provides a TTC prompt system based on dynamic tactile interaction, including: an environmental perception module 110, a collision prediction module 120 and a dynamic tactile warning module 130. The module composition of the TTC prompt system only represents its functional responsibilities in the system, and does not represent the distinction between actual devices. Among them, the function of the environmental perception module 110 is to collect dynamic information of surrounding traffic participating vehicles in real time; the function of the collision prediction module 120 is to perform real-time analysis and calculation of the traffic participating vehicle information provided by the environmental perception module, and then predict the collision time (TTC) and its risk; the function of the dynamic tactile warning module 130 is to dynamically generate and transmit tactile feedback signals (vibration signals) to prompt the driver based on the collision warning information provided by the collision prediction module 120.

[0052] In one embodiment, the environmental perception module 110 is equipped with necessary vehicle-mounted sensors (such as radar, lidar, camera, etc.) or a vehicle-to-everything (V2X) communication system to obtain information about other vehicles participating in the traffic, including but not limited to: boundary coordinate sets, speed, acceleration, heading angle and other parameters of the vehicles participating in the traffic, and transmits these data to the collision prediction module 120.

[0053] The collision prediction module 120 is equipped with sufficient computing power to achieve real-time performance of TTC prediction and tactile feedback enablement.

[0054] The dynamic tactile warning module 130 uses multiple distributed vibration units (such as vibration motors or other actuators). Each vibration unit can be independently controlled and the pulse width modulation (PWM) technology is used to adjust the working state of the vibration unit to generate vibration feedback of different intensities and frequencies.

[0055] In order to accurately map the direction of the collision warning signal in space, each vibration unit is arranged in the contact area between the driver and the seat, such as the seat cushion and backrest of the driver's seat, so that the driver can obtain more timely and intuitive warning information. The installation position of the vibration unit should conform to the principles of ergonomics to ensure that the driver can clearly and accurately perceive the tactile prompts from different directions without interference, and feel the intensity of the collision risk, while avoiding discomfort caused by excessive or too frequent vibrations. Through reasonable spatial layout, the combined operation of the vibration units can correspond to a specific direction outside the vehicle (such as the left front, right rear, rear, etc.), thereby ensuring that the tactile prompts can be conveyed to the driver in an intuitive and accurate way.

[0056] In another embodiment, the dynamic tactile warning module 130 has a driving circuit module for controlling the start and stop and vibration intensity of each vibration unit, which includes multiple motor driving chips or modules. This module is connected to the central control unit and receives the control signal from the upper collision prediction module 120 through the interface circuit. Each vibration unit should be linked with the driving circuit module and the interface circuit through a stable and low-latency connection method to ensure that after the collision warning information is triggered, the driving circuit module can dynamically adjust the output control signal according to the TTC value and collision direction contained in the collision warning information, activate the vibration unit in the corresponding area in the shortest time, realize the precise control of the vibration frequency and intensity of the vibration unit, and ensure that the tactile feedback signal is proportional to the actual collision risk.

[0057] The present invention also provides a TTC prompt method based on dynamic tactile interaction, and the specific implementation process is as follows.

[0058] S1. Collect relevant information of surrounding traffic vehicles in real time through the environment perception module and pass it to the collision prediction module.

[0059] S2. In the collision prediction module, based on the traffic participating vehicle information received in S1, the time to collision (TTC) between the vehicle and each traffic participating vehicle is calculated in real time to obtain a predicted value.

[0060] S3. Determine the TTC value calculated in S2: If the calculated TTC value is equal to or lower than the preset collision time threshold, determine that there is a potential collision risk and proceed to S4; if the calculated TTC value is higher than the preset collision time threshold, return to S2 and continue real-time TTC calculation.

[0061] S4. Spatially map the information of traffic vehicles that are judged to have a collision risk, determine their position and direction relative to the vehicle, and transmit this information to the dynamic tactile warning module; the dynamic tactile warning module enables the tactile interaction unit in the corresponding direction based on this information, and transmits a dynamic tactile warning signal to the driver.

[0062] S5. Continuously monitor the collision risk within a preset time: If the collision risk persists within the time, return to S4 and repeat the tactile feedback mapping and signal update; if the collision risk disappears within the time, enter S6.

[0063] S6. When the collision prediction module determines that the collision risk has been resolved, the dynamic tactile warning module terminates the tactile feedback prompt for the dangerous vehicle and ends the TTC prediction warning.

[0064] As a preferred embodiment, in S1, the environment perception module collects and records information including but not limited to the following traffic participating vehicles:

[0065] The coordinate point of the center position of the front axle of the vehicles involved in the traffic: Q(t) = (x0(t), y0(t)).

[0066] Boundary coordinate set P(t) of the participating vehicles: The external contour or body boundary data of the participating vehicles is preferably in the form of two-dimensional coordinates based on the vehicle coordinate system. The boundary coordinate set P(t) of the participating vehicles is:

[0067] P(t)={(x1(t),y1(t)),(x2(t),y2(t)),...,(x n (t),y n (t))}.

[0068] Among them, (x1(t),y1(t)), (x2(t),y2(t)), (x n (t),y n (t)) represent the coordinates of boundary point 1, boundary point 2, and boundary point n of the traffic participating vehicle at time t in the vehicle coordinate system.

[0069] Heading angle θ(t): The angle of the moving direction of the traffic participating vehicle, preferably expressed as an angle relative to the positive direction of the x-axis of the vehicle coordinate system.

[0070] Speed ​​v(t): the instantaneous speed of the traffic participating vehicles.

[0071] Acceleration a(t): the instantaneous acceleration of the traffic participating vehicle.

[0072] Timestamp t: Data collection time information, used to achieve time synchronization with other modules of the vehicle system.

[0073] At the same time, obtain the coordinates of the center position of the front axle of the vehicle and the coordinate set of the vehicle boundary P ego (t), vehicle heading angle, velocity, acceleration and other data.

[0074] It is preferred to use two-dimensional coordinates based on the vehicle coordinate system, where the boundary coordinate set P of the vehicle is ego (t) is:

[0075] P ego (t) = {(x ego1 (t),y ego1 (t)),(x ego2 (t),y ego2 (t)),...,(x egom (t),y egom (t))}

[0076] Among them, (x ego1 (t),y ego1(t)),(x ego2 (t),y ego2 (t)),(x egom (t),y egom (t)) represent the coordinates of boundary point 1, boundary point 2, and boundary point m of the vehicle in the vehicle coordinate system at time t.

[0077] Preferably, for the number n of coordinates in the boundary point set of traffic participating vehicles and the number m of coordinates in the self-vehicle boundary check point set, the maximum value can be determined based on the actual computing power of the environmental perception module and the collision prediction module, and the minimum value should be 4, forming the basic rectangular shape of the vehicle, which is sufficient to establish the vehicle boundary to ensure the existence of the space-time polygon.

[0078] Preferably, in S2, the collision prediction module calculates TTC prediction based on a physical model, the basic principle of which is:

[0079] First, record the current moment t0, and use 0.1s as the step length to predict the vehicle boundary coordinates at each moment after the current moment until the prediction reaches the statistical end step number; where t k The vehicle boundary coordinates at the moment are:

[0080]

[0081] Where x0 and y0 are the initial front axle center coordinates of the vehicle, v(t0) is the initial speed of the vehicle, t0 is the current time, and t k is the prediction time, a is the acceleration of the vehicle, sinθ and cosθ are the sine and cosine values ​​of the vehicle's heading angle; τ is the integral variable of the position integral in the outer integral of the formula, which represents the time from the initial time t0 to the prediction time t k At a certain moment between t0 and t0, τ′ is the integral variable of the acceleration integral in the inner integral of the formula, which represents a certain moment between the initial moment t0 and the outer integral variable τ.

[0082] Judge t k Whether the vehicle collides at time t is determined by calculating k Whether there is any intrusion between the two vehicles at time instant, that is, whether any boundary coordinate point of other traffic participating vehicles is located inside the space-time polygon composed of the boundary coordinate set of the own vehicle.

[0083] Specifically, click P A (t k )=(x Ai (t k ),y Ai (t k )) is the traffic participating vehicle A vehicle t k The i-th boundary point at time t kThe set of vehicle boundary coordinates at this moment is:

[0084] P ego (t k )={(x ego1 (t k ),y ego1 (t k )),(x ego2 (t k ),y ego2 (t k )),...,(x egom (t k ),y egom (t k ))}

[0085] For point P A (t k ), starting from this point, calculate the coordinate set P of the vehicle boundary ego (t k ) and the angle β between the positive direction of the x-axis of the vehicle coordinate system. Then point P A (t k ) to the boundary point j of the vehicle and the angle β between the positive direction of the x-axis of the vehicle coordinate system j for:

[0086] β j =atan2(y egoj (t k )-y Ai (t k ),x egoj (t k )-x Ai (t k ));

[0087] Among them, x egoj (t k ),y egoj (t k ) is t k The horizontal and vertical coordinates of the vehicle boundary point j at the moment, x Ai (t), y Ai (t) are t k The horizontal and vertical coordinates of the boundary point i of vehicle A at the moment of traffic.

[0088] Among them, atan2(y,x) is the inverse tangent function, which calculates the angle between the line connecting the point (x,y) and the origin and the positive direction of the x-axis.

[0089] Point P A (t k ) to the coordinates of all boundary points of the vehicle, forming the angles β1, β2, ..., βm Add up and get the total angle and Θ sum :

[0090]

[0091] If t k Moment Θ sum = ±2π, then point P A (t cls ) is inside the polygon, indicating the boundary point P of car A A (t k ) is within the boundary of car B, i.e. t k At time, the two cars collided.

[0092] At this time, the predicted collision time of car A TTC = t k -t0

[0093] Similarly, the above method can be used to calculate the spatiotemporal coordinates of any boundary point of other traffic participating vehicles.

[0094] As a preferred embodiment, in S3, the preset collision risk threshold TTC * 2s.

[0095] As a further preference, in S4, in order to ensure dynamics, as the direction of the traffic participating vehicle with collision risk changes relative to the own vehicle, the position of the corresponding enabled tactile interaction unit also changes in real time; as the collision time between the traffic participating vehicle with collision risk and the own vehicle calculated in real time decreases, the vibration intensity of the corresponding enabled tactile interaction unit also increases in real time.

[0096] Specifically, point Q(t0)=(x A0 (t0),y A0 (t0)) is the front axle center position coordinate of vehicle A at the current time t0. The collision prediction module has calculated and predicted t k At time t, the two vehicles collide, and the TTC value is less than the collision time threshold TTC * At this time, the collision prediction module starts to calculate the warning azimuth angle α of vehicle A relative to the vehicle itself, referring to the formula:

[0097] α=atan2(y A0 (t0),x A0 (t0))×180÷π

[0098] Among them, atan2(y,x) is the inverse tangent function, which calculates the angle between the line connecting the point (x,y) and the origin and the positive direction of the x-axis.

[0099] The collision prediction module determines the tactile interaction unit (vibration unit) that needs to work in this direction based on the warning azimuth angle α, and then calculates and updates the collision time TTC between the two vehicles in real time, and changes the vibration intensity ε of the vibration unit corresponding to the azimuth angle α according to the value of TTC.

[0100] As a preferred embodiment, when the collision time is equal to the collision time threshold, the vibration intensity ε is the maximum vibration intensity ε max 50% of the collision time; when the collision time is less than or equal to 1s, the vibration intensity ε is the maximum vibration intensity ε max .

[0101] Reference formula for calculating the vibration intensity ε corresponding to other collision times:

[0102]

[0103] Wherein, in S5, the preset time is 0.5s.

[0104] The present invention will be further described below with reference to specific embodiments.

[0105] Example 1

[0106] like Figure 2 As shown, in this embodiment, the ego vehicle (ego) changes lanes to overtake, and vehicle A in another lane in the same direction is driving normally and quickly. The driver is unaware of the overtaking risk. At this time, the TTC prompt system issues an alarm to prompt the driver to avoid the collision risk.

[0107] like Figure 3 As shown, the early warning process of this embodiment includes the following steps:

[0108] S310, the environment perception module obtains information about vehicle A and the ego (ego) in real time through on-board sensors (such as radar, lidar, camera, etc.) or vehicle-to-vehicle communication systems (such as V2X), including but not limited to: the coordinate point Q(t) of the center position of the front axle of vehicle A, the coordinate set P of the vehicle body boundary, and the coordinates of the vehicle body boundary. A (t), speed v A (t), acceleration a A (t), heading angle θ A (t); the body boundary coordinate set P of the ego vehicle (ego) ego (t), speed v ego (t), acceleration a ego (t), heading angle θ ego (t).

[0109] S320, the collision prediction module calculates t based on the real-time collected information of vehicle A and the ego vehicle (ego) kAt time t, the position of vehicle A is A*, and the position of the ego vehicle is ego*. It is found that there is a collision risk between the two vehicles, and the TTC prediction value is obtained.

[0110] S330: The TTC predicted in step S320 A The value is consistent with the preset collision time threshold TTC * For comparison, when TTC A ≤TTC * When TTC A >TTC * When , it returns to step S320 to continue to calculate TTC in real time A .

[0111] S340: Spatially map the information of vehicle A, a traffic participant determined to be at collision risk, to determine its warning azimuth angle α relative to the ego vehicle (ego). This information is then transmitted to a dynamic tactile warning module. Based on this information, the dynamic tactile warning module activates the tactile interaction unit in the corresponding position on the driver's seat (cushion) of vehicle A in real time, transmitting a dynamic tactile warning signal to the driver.

[0112] S350, continuously monitor the collision risk within 0.5s: If the collision risk persists within 0.5s, return to step S340 and repeat the tactile feedback mapping and signal update; if the collision risk disappears for more than 0.5s, proceed to step S360.

[0113] S360: The ego driver perceives the tactile prompt and performs a collision avoidance maneuver. When the collision prediction module determines that the collision risk has been resolved, the dynamic tactile warning module stops the collision prompt for the dangerous vehicle A, ending the TTC prediction warning.

[0114] Wherein, in step S310:

[0115] Specifically, P A The boundary coordinate set of (t) is:

[0116] P A (t) = {(x A1 (t),y A1 (t)),(x A2 (t),y A2 (t)),...,(x An (t),y An (t))};

[0117] Among them, in step S320:

[0118] Specifically, the collision prediction module calculates TTC prediction based on a physical model, and its basic principle is:

[0119] 1. First, record the current time t0, and predict the vehicle boundary coordinates at each time after the current time with a step length of 0.1s until the end step; where t k The vehicle boundary coordinates at the moment are:

[0120]

[0121] Where x0 and y0 are the initial coordinates of the vehicle, v(t0) is the initial velocity of the vehicle, t0 is the current moment, and t k is the prediction time, a is the acceleration of the vehicle, sinθ and cosθ are the sine and cosine values ​​of the vehicle's heading angle; τ is the integral variable of the position integral in the outer integral of the formula, which represents the time from the initial time t0 to the prediction time t k At a certain moment between t0 and t0, τ′ is the integral variable of the acceleration integral in the inner integral of the formula, which represents a certain moment between the initial moment t0 and the outer integral variable τ.

[0122] Preferably, the number of steps at the end of the statistics is set to 50 steps.

[0123] 2. Judge t k Whether the vehicle collides at time t is determined by calculating k Whether there is any intrusion between the two vehicles at time instant, that is, whether any boundary coordinate point of other traffic participating vehicles is located inside the space-time polygon composed of the boundary coordinate set of the own vehicle.

[0124] Specifically, click P A (t k )=(x Ai (t k ),y Ai (t k )) is car A k The i-th boundary point at time t, the boundary coordinate set of the vehicle:

[0125] P ego (t k )={(x ego1 (t k ),y ego1 (t k )),(x ego2 (t k ),y ego2 (t k )),...,(x egom (t k ),y egom (t k ))}

[0126] For point P A (tk ), starting from this point, calculate the coordinate set P of the vehicle boundary ego (t k ) and the angle β between the positive direction of the x-axis of the vehicle coordinate system. Then point P A (t k ) to the boundary point j of the vehicle and the angle β between the positive direction of the x-axis of the vehicle coordinate system j for:

[0127] β j =atan2(y egoj (t k )-y Ai (t k ),x egoj (t k )-x Ai (t k ));

[0128] Among them, x egoj (t k ),y egoj (t k ) is t k The horizontal and vertical coordinates of the vehicle boundary point j at the moment, x Ai (t), y Ai (t) are t k The horizontal and vertical coordinates of the boundary point i of vehicle A at the moment of traffic.

[0129] Here, atan2(y,x) is the inverse tangent function, which calculates the angle from the point (x,y) to the origin.

[0130] Point P A (t k ) to the coordinates of all boundary points of the vehicle, forming the angles β1, β2, ..., β m Add up and get the total angle and Θ sum :

[0131]

[0132] If t k Moment Θ sum = ±2π, then point P A (t cls ) is inside the polygon, indicating the boundary point P of car A A (t k ) is within the boundary of car B, i.e. t k At time, the two cars collided.

[0133] At this time, the predicted collision time TTC of vehicle A is A =t k-t0

[0134] Among them, t k is the predicted collision time, and t0 is the current time.

[0135] In step S340:

[0136] Specifically, to ensure dynamics, as the direction of the traffic vehicle with collision risk changes relative to the own vehicle, the position of the corresponding enabled tactile interaction unit also changes in real time; as the collision time calculated in real time between the traffic vehicle with collision risk and the own vehicle decreases, the vibration intensity of the corresponding enabled tactile interaction unit also increases in real time.

[0137] Specifically, point Q(t0)=(x A0 (t0),y A0 (t0)) is the front axle center position coordinate of vehicle A at the current time t0. The collision prediction module has calculated and predicted t k At time t, the two vehicles collide, and the TTC value is less than the collision risk threshold. At this time, the collision prediction module starts to calculate the warning azimuth angle α of vehicle A relative to the vehicle itself, referring to the formula:

[0138] α=atan2(y A0 (t0),x A0 (t0))×180÷π

[0139] Where atan2(y,x) is the inverse tangent function, which calculates the angle between the line connecting the point (x,y) and the origin and the positive x-axis of the vehicle coordinate system.

[0140] The collision prediction module determines the tactile interaction unit (vibration unit) that needs to work in this direction according to the warning azimuth angle α. Figure 4 As shown, in this embodiment, multiple vibration units 131 are arranged on the seat cushion 200 according to corresponding orientations. At this time, the vibration unit 131 near the corresponding orientation angle α on the driver's seat starts to work, warning the driver that there is a risk of collision with vehicle A in this direction.

[0141] Then calculate and update the collision time TTC of the two vehicles in real time A , according to the TTC A The value of changes the vibration intensity ε of the tactile interaction unit. Preferably, when the collision time is equal to the collision risk threshold, the vibration intensity ε is the maximum vibration intensity ε max 50%; when the collision time is less than or equal to 1s, the vibration intensity ε is the maximum vibration intensity ε max .

[0142] Specifically, the vibration intensity ε corresponding to other collision times is calculated using the following formula:

[0143]

[0144] Wherein, in step S350, the preset time is 0.5s.

[0145] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A TTC prompting method based on dynamic tactile interaction, characterized in that: The steps include: Step 1: Obtain dynamic information of surrounding traffic participating vehicles, including: boundary coordinate set of traffic participating vehicles and heading angle, speed, and acceleration of traffic participating vehicles; Step 2: Calculating the collision time between the ego vehicle and each participating vehicle based on the dynamic information and the ego vehicle's motion state, and comparing the collision time with a set collision time threshold; if the collision time is equal to or lower than the collision time threshold, determining that there is a collision risk; Step 3: Determine the position of the traffic vehicle with a collision risk relative to the driver's vehicle, and transmit the position information to the dynamic tactile warning module; the dynamic tactile warning module activates the vibration unit corresponding to the position information to transmit a warning signal to the driver; In step 1, the boundary coordinate set of the traffic participating vehicles is expressed as: P(t)={(x1(t),y1(t)),(x2(t),y2(t)),...,(x n (t),y n (t))}; Among them, (x1(t),y1(t)), (x2(t),y2(t)), (x n (t),y n (t)) represent the coordinates of boundary point 1, boundary point 2, and boundary point n of the traffic participating vehicle at time t in the ego vehicle coordinate system; the value of n is: n≥4; In step 2, the method for calculating the collision time between the vehicle and the participating vehicles is: According to the set collision prediction step, the boundary coordinates of the vehicle and the boundary coordinates of the participating vehicles at each moment after the current moment are predicted and calculated respectively; if t k If any boundary point of the traffic participating vehicles at the moment is located inside the spatiotemporal multi-deformation composed of the boundary coordinate set of the vehicle, then it is judged that t k The time is the collision time; the difference between the collision time and the current time is the collision time; Judge t k The method to determine whether the boundary point i of the traffic participating vehicle A is located inside the spatiotemporal multi-dimensional structure composed of the vehicle boundary coordinate set is: Calculate t separately k The angle between the line connecting the boundary point i of the traffic participating vehicle A and each boundary point of the ego vehicle and the positive direction of the x-axis of the ego vehicle coordinate system is: Among them, t k The angle between the line connecting the boundary point i of the traffic participant vehicle A and the boundary point j of the ego vehicle and the positive direction of the x-axis of the ego vehicle coordinate system is: β j =atan2(y egoj (t k )-y Ai (t k ),x egoj (t k )-x Ai (t k )); Among them, x egoj (t k ),y egoj (t k ) is t k The horizontal and vertical coordinates of the vehicle boundary point j at the moment, x Ai (t), y Ai (t) are t k The horizontal and vertical coordinates of the boundary point i of vehicle A at the moment of traffic; Sum all included angles: If t k The sum of all angles at the moment Θ sum = ±2π, then the boundary point i of the traffic participating vehicle A is inside the space-time polygon composed of the boundary coordinate set of the vehicle itself; m represents the number of boundary points of the vehicle itself; In the step three, the method further includes: adjusting the vibration intensity and vibration frequency of the vibration unit according to the collision time; Among them, the shorter the collision time, the greater the vibration intensity of the corresponding vibration unit and the higher the vibration frequency.

2. The TTC prompting method based on dynamic tactile interaction according to claim 1, characterized in that: When TTC = TTC * When the vibration intensity of the vibration unit is: ε=50%ε max ; When 1s<TTC<TTC * When , the vibration intensity of the vibration unit is: When TTC≤1s, the vibration intensity of the vibration unit is: ε=ε max ; Among them, ε max is the maximum vibration intensity of the vibration unit, TTC is the collision time, TTC * is the collision time threshold.

3. The TTC prompting method based on dynamic tactile interaction according to claim 1 or 2, characterized in that: The collision time threshold is set to 2s.

4. The TTC prompting method based on dynamic tactile interaction according to claim 3, characterized in that: The collision prediction step size is set to 0.1 s.

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