A method and system for active adjustment of a co-driver footrest in a synergistic active and passive safety system

Abstract

The application discloses a kind of active adjustment method and system of passive safety coordination's co-driver footrest, belong to the field of automobile safety technology.The method is by continuously monitoring the vehicle external environment and passenger state information;When potential vehicle collision risk is predicted based on environmental information, obtain the passenger's passenger sign information of co-driver position;Comprehensive potential vehicle collision risk and passenger sign information, generate matched co-driver footrest adjustment control instruction;According to control instruction, drive embedded in the footrest device of co-driver floor area and execute preset protective movement, so that it moves to preset protection posture, to provide restraint and support for the feet of passenger before collision occurs.The system and method aim to solve the problem that the co-driver footrest in the prior art is insufficient in supporting and protecting the feet of passengers under collision conditions, especially unable to consider the protection needs of passengers of different body types, and provide an active pre-adjustment protection scheme that is fast-responding and highly adaptable.

Description

Technical Field

[0001] This invention relates to the field of automotive safety technology, and in particular to a method and system for active adjustment of the passenger-side footrest that combines active and passive safety features. Background Technology

[0002] With the rapid development of new energy vehicles, in pursuit of passenger comfort and a flat, aesthetically pleasing interior space, the passenger-side footrest is often designed to be flat or at a slight angle. However, in frontal collisions and other accidents, this design may result in occupants (especially smaller occupants) lacking effective foot support, causing their legs to shift upwards and collide with hard structures such as the air conditioner below the dashboard, resulting in serious leg and foot injuries. Currently, the European New Car Assessment Programme 2026 Protocols (E-NCAP 2026) has introduced a female dummy leg injury assessment indicator, placing higher demands on foot protection.

[0003] Existing technical solutions mostly focus on macroscopic optimization of the vehicle body structure, improving overall safety by reducing front bumper intrusion. However, for pure electric vehicles where front bumper intrusion is already well controlled, it is difficult to specifically address the shortcomings in localized protection of the passenger foot area. Some technologies employ passively adjustable foot pedal devices, but their protective effectiveness is highly dependent on specific ergonomic parameters, has poor adaptability to mainstream flat carpet-like structures, and cannot provide stable support for smaller occupants. Furthermore, their response speed depends on passive triggering after a collision, exhibiting defects such as protection lag and insufficient adaptability. Summary of the Invention

[0004] The present invention aims to solve the problem that the existing technology of passenger footrest provides insufficient support and protection for the occupant's feet under collision conditions, and in particular, cannot meet the protection needs of occupants of different body types. It provides a rapid response and highly adaptable active pre-adjustment protection method and system.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for active adjustment of the passenger-side footrest in a coordinated active and passive safety manner, comprising: S1: Continuously monitors the vehicle's external environment and occupant status information; S2: When a potential vehicle collision risk is predicted based on the environmental information, obtain the occupant's vital signs information in the front passenger seat. S3: Based on the potential vehicle collision risk and the occupant vital signs information, generate a matching control command for adjusting the passenger footrest. S4: According to the control command, drive the footrest device embedded in the passenger floor area to perform a preset protective movement, move it to a preset protective posture, so as to provide restraint and support for the occupant's feet before a collision occurs.

[0006] Furthermore, in S1, the continuous monitoring of the vehicle's external environment is accomplished through the vehicle's active safety system; the active safety system calculates collision risk assessment parameters, including the estimated collision time, based on the fusion perception data of millimeter-wave radar and a front camera.

[0007] Furthermore, in S2, the acquisition of occupant vital signs information is achieved through an in-vehicle occupant status monitoring system. The occupant status monitoring system identifies the occupant's facial features and sitting posture, and outputs a classification signal characterizing the occupant's body type accordingly.

[0008] Furthermore, in S3, the initial warning conditions for triggering the generation of the matching passenger footrest adjustment control command include: the expected collision time is less than or equal to 2.0 seconds and shows a decreasing trend, the relative speed is greater than or equal to 30 km / h, and the longitudinal deceleration of the vehicle is greater than or equal to 0.3g.

[0009] Furthermore, the generation of matching passenger footrest adjustment control commands in S3 includes: Advanced assessment of potential vehicle collision risks is conducted, and when the predicted collision time is continuously reduced to less than or equal to 1.8 seconds, it is judged as a high-risk collision event. Based on the estimated collision type, estimated relative speed, and occupant vital signs information of the high-risk collision event, a preset adjustment strategy mapping table is queried to determine the adjustment target position information for the footrest device.

[0010] Furthermore, the adjustment target position information includes at least a preset target rotation angle and / or a preset target translation distance for the footrest; the preset adjustment strategy mapping table stores combinations of preset target rotation angles and target translation distances corresponding to different collision types and different occupant body types.

[0011] Furthermore, the preset adjustment strategy mapping table includes at least the following correspondences: When the estimated collision type is a 100% frontal collision and the occupant is small in size, the preset target rotation angle is 58°±2°, and the preset target translation distance is a rearward movement of (40±3) mm; When the estimated collision type is a 100% frontal collision and the occupant is of large size, the preset target rotation angle is 52° ± 2°, and no translational movement is required; When the estimated collision type is a 40% offset frontal collision and the occupant is of medium build, the preset target rotation angle is 55°±2°, and the preset target translation distance is a rearward movement of (30±3) mm; When the estimated collision type is a low overlap collision and the occupant is small in size, the preset target rotation angle reaches 60° and the preset target translation distance is a backward movement of (15±3) mm.

[0012] Furthermore, in S4, the footrest device embedded in the passenger floor area is driven to perform a preset protective movement, specifically by controlling the rotation drive mechanism and the translation drive mechanism in the footrest device to make the footrest rotate and / or translate linearly to reach the preset protective posture.

[0013] Furthermore, the footrest device performs the preset protective movement using a hybrid control strategy that combines position control and force control: in the initial stage of movement, position control is mainly used to achieve rapid positioning; when approaching the target adjustment position, it switches to force control mode and performs fine-tuning positioning based on the feedback signal from the pressure sensor installed inside the footrest to ensure close support for the occupant's feet.

[0014] Furthermore, the acceleration of the drive motor in the footrest device is limited by a preset maximum threshold.

[0015] Furthermore, during the movement of the footrest device, the status parameters of its drive motor are monitored in real time; when an abnormal state, including stall or over-temperature, is detected, an emergency stop procedure is triggered.

[0016] Furthermore, after the potential vehicle collision risk is eliminated, the footrest device is controlled to return to its initial hidden position; and after each movement is completed, a self-diagnosis is performed and the execution process parameters are recorded.

[0017] Secondly, based on the same inventive concept as the first aspect of this invention, a co-operational active adjustment system for the passenger footrest is provided, used to implement the co-operational active adjustment method for the passenger footrest mentioned in the first aspect of this invention, the system comprising: The sensing module is used to collect vehicle environmental status data and occupant status data; The central control module is used to receive and process the data from the sensing unit, predict collision risks, and generate footrest adjustment instructions. An execution module is used to receive the adjustment command and drive the footrest device to complete the corresponding position and posture adjustment; in: The sensing module includes: The forward collision detection unit uses data fusion from millimeter-wave radar and a forward-looking camera. The occupant status monitoring unit is used to identify occupant characteristics and output occupant body type classification; The vehicle dynamic acquisition unit is used to acquire real-time motion status signals of the vehicle. The central control module includes a controller, a storage module, and a deep learning algorithm model running on the controller, used to assess collision risk, identify collision type, and query the adjustment strategy mapping table. The execution module is an embedded footrest adjustment assembly, which includes: A base bracket fixed to the vehicle floor; A rotary drive assembly that connects to and drives the footrest to rotate; A translation drive assembly that drives the footrest and the rotation drive assembly to move in the front-to-back direction of the vehicle body.

[0018] Furthermore, the footrest is made of fiber-reinforced plastic with a non-slip surface and an embedded thin-film pressure sensor for monitoring foot contact pressure.

[0019] Thirdly, the present invention also provides a vehicle equipped with an active passenger footrest adjustment system as provided in the second aspect of the present invention, which provides active and passive safety coordination.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This application provides a method, system, and vehicle for active and passive safety coordination of the passenger side footrest. By continuously monitoring the vehicle's external environment and occupant status information, it dynamically generates adjustment commands when a potential collision risk is predicted and drives the footrest device to move to a preset protective posture before a collision occurs. This provides timely restraint and support for the occupant's feet, effectively reducing the risk of leg and foot injuries, while adapting to the personalized protection needs of different collision types and occupant body shapes.

[0021] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a method for actively adjusting the passenger footrest in a coordinated active and passive safety manner according to an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the initial state of the occupant's feet according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of a small-sized passenger's feet in a 100% frontal collision state according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the L-shaped occupant's feet in a 100% frontal collision state according to an embodiment of the present invention.

[0027] Figure 5 This is a structural diagram of an active adjustment system for the passenger footrest, which combines active and passive safety features, according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: In one embodiment, such as Figure 1 As shown, this embodiment provides a method for active adjustment of the passenger-side footrest in a coordinated active and passive safety manner. The method includes the following steps: Step S1: Continuously monitor the vehicle's external environment and occupant status information; Step S2: When a potential vehicle collision risk is predicted based on the environmental information, obtain the occupant's vital signs information in the front passenger seat. Step S3: Based on the potential vehicle collision risk and the occupant vital signs information, generate a matching control command for adjusting the passenger footrest. Step S4: According to the control command, drive the footrest device embedded in the passenger floor area to perform a preset protective movement, move it to a preset protective posture, so as to provide restraint and support for the occupant's feet before a collision occurs.

[0030] Furthermore, in S1, the continuous monitoring of the vehicle's external environment is accomplished through the vehicle's active safety system; the active safety system calculates collision risk assessment parameters, including the estimated collision time, based on the fusion perception data of millimeter-wave radar and a front camera.

[0031] Furthermore, in S2, the acquisition of occupant vital signs information is achieved through an in-vehicle occupant status monitoring system. The occupant status monitoring system identifies the occupant's facial features and sitting posture, and outputs a classification signal characterizing the occupant's body type accordingly.

[0032] Specifically, the continuous monitoring of the vehicle's external environment is accomplished through the vehicle's active safety system. This active safety system does not rely on a single sensor but rather on fused perception data from millimeter-wave radar and a forward-facing camera. Millimeter-wave radar provides precise distance, relative speed, and angle information, exhibiting excellent robustness, especially in adverse weather conditions; while the forward-facing camera provides rich visual information, such as target classification, shape, and relative position. By fusing the advantages of these two sensors, for example, by processing the data using Kalman filtering or deep learning algorithms, a more comprehensive and accurate understanding of the vehicle's external environment can be generated. Based on this fused perception data, the active safety system can calculate various collision risk assessment parameters, including the estimated time of collision (TTC). TTC is a key indicator, typically obtained by dividing the target distance by the relative speed; its continuously decreasing trend is an important basis for judging collision risk. In addition, parameters such as relative speed, relative distance, and preliminary collision type can be calculated, providing data support for subsequent risk assessment.

[0033] Meanwhile, the acquisition of occupant vital signs information is achieved through an in-vehicle occupant status monitoring system. This system typically integrates an in-vehicle camera (e.g., an infrared camera to adapt to different lighting conditions) and / or seat pressure sensors. The occupant status monitoring system can identify the occupant's facial features and posture. For example, through image processing and pattern recognition technology, the system can analyze the occupant's facial features to help determine their age group or identity, and assess the occupant's posture by identifying key body points, such as whether they are leaning forward, backward, or to the side. Combining facial features and posture information, the system can output a classification signal characterizing the occupant's body type. These classification signals can categorize occupants into preset body type categories, such as "small," "medium," or "large," and can even distinguish between "children" and "adults." This classification signal provides the basic data for subsequent personalized adjustment of the footrest.

[0034] Furthermore, the occupant body type classification (small, medium, and large) described in this invention is based on commonly used ergonomic data and crash test dummy models to provide a clear implementation benchmark. This classification can be determined by the occupant status monitoring system based on occupant facial features and height / sitting height data estimated from their sitting posture, and can be coded according to the following standards: Small body type (S-type): Generally refers to the body type of adult females whose height is at or below the 5th percentile (e.g., height in the range of approximately 150-155 cm), or corresponds to the size characteristics of the 5% female dummy models in industry standards (such as E-NCAP).

[0035] Medium build (M type): This usually refers to the body type of an adult male whose height is close to the 50th percentile (e.g., a height of about 170-175 cm), or the size characteristics of a 50% male dummy model in the industry standard.

[0036] Large build (L-shape): Generally refers to the body type of adult males whose height is at or above the 95th percentile (e.g., approximately 185-190 cm tall). Through the aforementioned technical solution, continuous monitoring of the vehicle's external environment no longer relies on a single sensor. Instead, it integrates perception data from millimeter-wave radar and a forward-facing camera through the vehicle's active safety system. This allows for a more comprehensive and accurate assessment of potential collision risks and the calculation of precise estimated collision times and other key parameters. This multi-sensor fusion mechanism significantly improves the robustness and reliability of environmental perception, enabling effective operation even under complex or severe weather conditions and providing a solid data foundation for subsequent collision risk prediction. Simultaneously, occupant vital signs are acquired through an in-vehicle occupant status monitoring system. This system identifies occupants' facial features and posture, outputting classification signals characterizing their body shape. This allows footrest adjustment to be personalized based on the occupant's actual body shape, rather than a universal preset. For example, the required restraint and support positions for the feet during a collision may differ for occupants of different body types. By accurately identifying the occupant's body shape, the system can generate more suitable adjustment and control commands, ensuring that the footrest moves to the most suitable protective posture for the occupant before a collision occurs. This provides effective restraint and support for the occupant's feet to the greatest extent, significantly improving the protective effect of the active and passive safety cooperative system and the safety of the occupants.

[0037] Furthermore, in S3, the initial warning conditions for triggering the generation of the matching passenger footrest adjustment control command include: the expected collision time is less than or equal to 2.0 seconds and shows a decreasing trend, the relative speed is greater than or equal to 30 km / h, and the longitudinal deceleration of the vehicle is greater than or equal to 0.3g.

[0038] Specifically, the phrase "expected collision time less than or equal to 2.0 seconds and decreasing" refers to the time to collision (TTC) expected to occur when the vehicle continues to travel at its current speed and direction under the current vehicle motion conditions, meeting specific conditions. This parameter is typically calculated by the vehicle's active safety system by processing data fused from sensors such as millimeter-wave radar and a forward camera, calculating in real time the relative distance and speed between the vehicle and the obstacle ahead. Setting a 2.0-second threshold aims to allow sufficient response and execution time for the footrest adjustment mechanism. Simultaneously, requiring a decreasing trend in the expected collision time further confirms the persistence and escalation of collision risk, effectively avoiding false triggers caused by brief TTC fluctuations or instantaneous sensor errors.

[0039] The "relative speed greater than or equal to 30 km / h" refers to the speed difference between the vehicle and the obstacle in front. This parameter is also calculated by the vehicle's active safety system based on sensor data such as millimeter-wave radar and a front camera. Setting a threshold of 30 km / h aims to focus the warning triggering conditions on collision events that may pose a high risk of injury to occupants, thereby excluding scenarios with low energy, such as low-speed collisions or minor scratches, where the need for foot protection is not so urgent.

[0040] The phrase "vehicle longitudinal deceleration greater than or equal to 0.3g" refers to the degree of deceleration of the vehicle along the direction of travel, usually expressed as a multiple of the gravitational acceleration g. This parameter can be calculated and monitored in real time using data from the vehicle's inertial measurement unit (IMU) or wheel speed sensors combined with a vehicle dynamics model. Setting a threshold of 0.3g aims to identify situations where the vehicle is undergoing emergency braking or has already decelerated sharply before a collision. This high-intensity deceleration is usually a signal of extremely high collision risk, indicating that the vehicle is in an emergency avoidance situation or is about to collide, requiring immediate activation of protective measures.

[0041] The aforementioned technical solution comprehensively assesses three key parameters—expected collision time, relative speed, and vehicle longitudinal deceleration—to form a multi-dimensional initial warning condition. This multi-parameter collaborative judgment mechanism significantly improves the system's accuracy and robustness in identifying real collision risks. Specifically, an expected collision time of less than or equal to 2.0 seconds with a decreasing trend ensures the timeliness of the warning and the continuity of the risk; a relative speed greater than or equal to 30 km / h excludes low-energy collisions, focusing on high-risk scenarios; and a vehicle longitudinal deceleration greater than or equal to 0.3g further confirms that the vehicle is in an emergency state. This combination of conditions effectively avoids unnecessary triggering of the footrest device due to fluctuations or misjudgments of a single parameter, reducing the system's malfunction rate. Simultaneously, it ensures that the protective movement of the footrest can be activated promptly and accurately before a truly high-risk collision occurs, providing reliable restraint and support for the occupants' feet, thereby maximizing the passive safety protection effect for the occupants.

[0042] Furthermore, the generation of matching passenger footrest adjustment control commands in S3 includes: Advanced assessment of potential vehicle collision risks is conducted, and when the predicted collision time is continuously reduced to less than or equal to 1.8 seconds, it is judged as a high-risk collision event. Based on the estimated collision type, estimated relative speed, and occupant vital signs information of the high-risk collision event, a preset adjustment strategy mapping table is queried to determine the adjustment target position information for the footrest device.

[0043] Through the aforementioned technical solution, this application introduces an "advanced confirmation" mechanism for potential vehicle collision risks, building upon the initial warning. Only when the expected collision time continuously decreases to a more stringent threshold (e.g., 1.8 seconds) is the event classified as a high-risk collision. This effectively avoids premature or unnecessary adjustments to the footrest due to non-emergency situations or data fluctuations, thereby improving system reliability and occupant comfort. Furthermore, by comprehensively considering the "estimated collision type," "estimated relative speed," and "occupant vital signs" of high-risk collision events, and querying a "preset adjustment strategy mapping table," this application can determine highly customized "adjustment target position information" for the footrest device. This refined adjustment strategy ensures that the footrest can move to the "preset protective posture" that most effectively restrains and supports the occupant's feet, based on the specific collision scenario and individual occupant characteristics. Compared to adjustments based solely on general warning conditions, this solution significantly improves the footrest's protective effect on the occupant's feet and lower limbs before a collision, minimizing the risk of collision injury and thus optimizing the synergy between active and passive safety.

[0044] Furthermore, the adjustment target position information includes at least a preset target rotation angle and / or a preset target translation distance for the footrest; the preset adjustment strategy mapping table stores combinations of preset target rotation angles and target translation distances corresponding to different collision types and different occupant body types.

[0045] The aforementioned technical solution defines the footrest's adjustment target position information as a quantifiable preset target rotation angle and / or preset target translation distance. Combined with a preset adjustment strategy mapping table, this allows the system to accurately query and obtain the rotational and / or translational motion parameters that the footrest should perform based on the type of high-risk collision event confirmed at an advanced level and the occupant's vital signs. This overcomes the limitations of relying solely on an abstract "protective posture," ensuring that the footrest device can perform highly customized and precise protective movements, providing restraint and support to the occupant's feet in the optimal posture and position. This precise adjustment capability significantly improves the protection of the occupant's lower limbs before a collision, effectively reducing the risk of collision injury, thus achieving superior performance in the coordination of active and passive safety.

[0046] Furthermore, as shown in Table 1 below, Table 1 is a preset adjustment strategy mapping table.

[0047] Table 1: Preset adjustment strategy mapping table.

[0048]

[0049] As shown in Table 1, the preset adjustment strategy mapping table includes at least the following correspondences: When the estimated collision type is a 100% frontal collision and the occupant is small in size, the preset target rotation angle is 58°±2°, and the preset target translation distance is a rearward movement of (40±3) mm; When the estimated collision type is a 100% frontal collision and the occupant is of large size, the preset target rotation angle is 52° ± 2°, and no translational movement is required; When the estimated collision type is a 40% offset frontal collision and the occupant is of medium build, the preset target rotation angle is 55°±2°, and the preset target translation distance is a rearward movement of (30±3) mm; When the estimated collision type is a low overlap collision and the occupant is small in size, the preset target rotation angle reaches 60° and the preset target translation distance is a backward movement of (15±3) mm.

[0050] Furthermore, in this embodiment, the foot position of the front passenger corresponding to the preset adjustment strategy mapping table is explained in more detail: as shown in the attached table. Figure 2 As shown, attached Figure 2This represents the initial foot position for the occupant, i.e., the position under normal driving conditions without a high-risk collision event. In the event of a high-risk collision, the footrest device adjusts for protection. Specifically: if the estimated collision type is a 100% frontal impact and the occupant is of small build, the foot position for the front passenger is as shown in the attached diagram. Figure 3 As shown, this maximizes the contact area between the foot and the pedal to distribute the load. If the estimated collision type is a 100% frontal collision and the occupant is of large build, the condition of the front passenger's feet is as shown in the attached figure. Figure 4 As shown, avoid excessive knee bending to prevent the knee from impacting the glove box; if the estimated collision type is a 40% offset frontal collision and the occupant is of medium build, move both feet away from the vehicle deformation intrusion zone; if the estimated collision type is a low overlap collision and the occupant is of small build, quickly retract the foot space to avoid intrusions.

[0051] By explicitly specifying the target rotation angle and / or target translation distance of the footrest under different collision types (such as 100% frontal collision, 40% frontal offset collision, and low overlap collision) and different occupant body sizes (such as small, large, and medium-sized) in a preset adjustment strategy mapping table, this application can achieve a high degree of matching between the adjustment action of the footrest device and the actual collision scenario and individual occupant characteristics. Specifically, when the system identifies a high-risk collision event, it can accurately query the most suitable footrest adjustment parameters from the mapping table based on the estimated collision type and occupant physical characteristics. For example, for a 100% frontal collision, a small occupant needs a larger rearward translation and rotation angle to provide tighter restraint, while a large occupant may only need rotation. For more complex scenarios such as offset collisions or low overlap collisions, this application also provides optimized combinations of rotation angles and translation distances to cope with asymmetric impacts or high intrusion risks. This refined and scenario-based adjustment strategy enables the footrest device to provide more precise and effective restraint and support for the occupant's feet before a collision occurs, significantly improving the protection of the occupant's lower limbs under different collision conditions. This effectively reduces the risk of foot and lower limb injuries during a collision and further enhances the overall performance of the active and passive safety coordination system.

[0052] Furthermore, in S4, the footrest device embedded in the passenger floor area is driven to perform a preset protective movement, specifically by controlling the rotation drive mechanism and the translation drive mechanism in the footrest device to make the footrest rotate and / or translate linearly to reach the preset protective posture.

[0053] Furthermore, the footrest device performs the preset protective movement using a hybrid control strategy that combines position control and force control: in the initial stage of movement, position control is mainly used to achieve rapid positioning; when approaching the target adjustment position, it switches to force control mode and performs fine-tuning positioning based on the feedback signal from the pressure sensor installed inside the footrest to ensure close support for the occupant's feet.

[0054] Specifically, the rotary drive mechanism in the footrest device typically consists of one or more motors, reduction gear sets, linkage mechanisms, etc., and its function is to drive the footrest to rotate around a certain axis, thereby changing the tilt angle of the footrest. For example, a motor mounted on the footrest pivot can be used to achieve precise angle adjustment of the footrest through gear transmission or belt transmission. The translation drive mechanism is responsible for driving the footrest to move linearly along the front-rear direction of the vehicle body. This can be achieved through linear actuators, lead screw and nut mechanisms, gear and rack mechanisms in conjunction with guide rails, etc. For example, a linear motor mounted on a base support or a lead screw driven by a motor can drive the footrest and its rotary drive mechanism to slide back and forth on the guide rail to adjust the distance between the footrest and the occupant's feet. Through the synergistic action of these two drive mechanisms, the footrest can achieve multi-dimensional movement, thereby flexibly adjusting its position and posture to adapt to different protection needs and occupant body shapes.

[0055] Based on this, the footrest device executes the preset protective movement using a hybrid control strategy combining position control and force control. Position control is a common control strategy aimed at precisely positioning the controlled object (here, the footrest) to a preset target position or angle. In the initial stages of movement, position control leverages its fast response and high positioning accuracy, allowing the footrest to quickly move from its initial position to an area approaching the target protective posture, thus gaining valuable pre-collision reaction time. This is typically achieved through closed-loop control of the encoder feedback of the drive motor. Force control, on the other hand, uses force or pressure as the control target. When the footrest approaches the occupant's feet, the system switches to force control mode to prevent the footrest from contacting the occupant's feet with excessive impact force. Force control monitors the contact force or pressure between the footrest and the occupant's feet in real time and adjusts it according to a preset force threshold, ensuring the footrest conforms to the occupant's feet in a gentle and stable manner. The advantage of this hybrid control strategy is that it combines the speed of position control with the flexibility of force control, ensuring both rapid response and passenger comfort and safety.

[0056] To further optimize the fit, the footrest is fine-tuned based on feedback signals from pressure sensors embedded within it. These pressure sensors, typically thin-film or piezoresistive, are cleverly integrated or arranged on or within the footrest's surface, allowing for real-time sensing of the contact pressure between the footrest and the occupant's feet. When the footrest approaches the occupant's feet in force-controlled mode, these sensors provide real-time pressure feedback signals to the central control module. Based on these feedback signals, the central control module fine-tunes the footrest's drive mechanism—for example, slightly adjusting the rotation angle or translation distance—until the detected pressure reaches a preset, comfortable, and effective support range. This fine-tuning ensures optimal fit between the footrest and the occupant's foot surface, providing sufficient support to restrain the feet while avoiding excessive localized pressure that could cause discomfort. Ultimately, through precise positional adjustment and flexible force control, the footrest closely conforms to the contours of the occupant's feet, providing uniform and effective support to ensure a snug fit.

[0057] Through the aforementioned technical solution, the footrest device overcomes the limitations of relying solely on a preset fixed posture when performing protective movements. In the initial stage of movement, position control ensures the footrest can respond quickly and move rapidly to the target area, effectively shortening reaction time. Subsequently, as the footrest approaches the occupant's feet, the system intelligently switches to force control mode and uses real-time feedback signals from the footrest's internal pressure sensors for fine-tuning and positioning. This hybrid control strategy allows the footrest to provide gentle yet precise support to the occupant's feet, avoiding discomfort or potential injury that might result from rigid contact. Simultaneously, it ensures maximum restraint and protection for the occupant's feet before a collision, significantly improving the overall performance of the active and passive safety system and the occupant's safety.

[0058] Furthermore, the acceleration of the drive motor in the footrest device is limited by a preset maximum threshold.

[0059] Furthermore, during the movement of the footrest device, the status parameters of its drive motor are monitored in real time; when an abnormal state, including stall or over-temperature, is detected, an emergency stop procedure is triggered.

[0060] To ensure the footrest device operates smoothly without causing secondary impact or discomfort to occupants during protective movements, the acceleration of the drive motor is strictly limited to a preset maximum threshold during start-up, acceleration, deceleration, and stopping. This threshold is typically determined through extensive simulation analysis, ergonomic studies, and practical testing, aiming to balance response speed with occupant comfort and safety. Specifically, this can be achieved by integrating acceleration limiting algorithms into the motor controller, for example, by smoothing the motor command signal, or by using a feedback control system to monitor and adjust the motor output in real time to ensure that the actual acceleration does not exceed the set value. Alternatively, mechanical structural design, such as the use of reduction gears or damping devices, can also assist in limiting acceleration.

[0061] Throughout the entire process of the footrest device performing its preset protective movements, the system continuously monitors the key status parameters of the drive motor in real time. These status parameters may include, but are not limited to, motor current, voltage, speed, position, and temperature. When the system detects an abnormal state in the motor, such as motor stalling due to external obstruction or internal fault, or motor exceeding temperature limits due to prolonged high-load operation or poor heat dissipation, the system will immediately trigger an emergency stop procedure. The emergency stop procedure typically includes steps such as quickly cutting off the motor power supply, activating the mechanical brake, and recording fault information to prevent motor damage, avoid fire risks, ensure occupant safety, and prevent injury from continued movement of the footrest under abnormal conditions.

[0062] Through the above technical solution, when the footrest device performs preset protective movements, the acceleration of its drive motor is limited to a safe range, effectively avoiding discomfort or potential injury to occupants caused by sudden acceleration or deceleration, while also reducing the impact on the mechanical structure. Furthermore, by monitoring the drive motor's status parameters in real time, the system can quickly trigger an emergency stop procedure upon detecting abnormalities such as stalling or exceeding temperature limits, promptly interrupting unsafe movements. This effectively prevents fire risks caused by motor overload damage or overheating, and avoids secondary injuries to occupants in an uncontrolled footrest state. This significantly improves the reliability, safety, and occupant protection effect of the entire active-passive safety coordination system, ensuring that the footrest device can safely and effectively perform its restraint and support functions at critical moments.

[0063] Furthermore, after the potential vehicle collision risk is eliminated, the footrest device is controlled to return to its initial hidden position; and after each movement is completed, a self-diagnosis is performed and the execution process parameters are recorded.

[0064] Specifically, when the vehicle's active safety system continuously monitors external environmental information and determines that the potential risk of a collision has been eliminated—for example, if the expected collision time is significantly longer than a safety threshold, or if a collision has occurred and the vehicle is in a stable state—the central control module will generate a recovery command. This command will drive the rotational drive mechanism and the translational drive mechanism in the footrest device to move in opposite directions, causing the footrest to smoothly return from its preset protective posture to a preset initial hidden position. The initial hidden position typically refers to the footrest being fully retracted, flush with the passenger side floor area, or in a default position that does not affect the passenger's normal riding comfort. During the recovery process, the system can use built-in position sensors to monitor the current position of the footrest in real time to ensure that it accurately and smoothly reaches the initial hidden position.

[0065] Furthermore, after each movement of the footrest device, whether a protective or recovery movement, the system triggers a self-diagnostic program and records the execution process parameters. The self-diagnostic program aims to perform functional checks on key components of the footrest device. For example, it checks whether the pressure sensors, position sensors, and encoders of the drive motor inside the footrest are functioning properly and whether there are any signal anomalies or drifts. Simultaneously, it can determine whether there are problems such as jamming, abnormal noises, or insufficient driving force in the rotary and translational drive mechanisms by short-term driving or monitoring parameters such as drive current and voltage, and checks whether the communication link between the central control module and the execution module is normal. Regarding the recording of execution process parameters, the system records in detail the start time, end time, target position, actual arrival position, movement speed curve, drive motor current / voltage, pressure sensor readings, self-diagnostic results, and ambient temperature for each adjustment movement. These parameters can be stored in the central control module's storage module or uploaded to the cloud via the vehicle network for further analysis and management.

[0066] Through the aforementioned technical solution, after the potential vehicle collision risk is eliminated, the footrest device can automatically return to its initial hidden position, effectively solving the problem of the footrest device being in an abnormal usage posture for extended periods. This ensures passenger comfort in non-emergency situations and avoids unnecessary occupation of vehicle interior space. Furthermore, by performing self-diagnosis and recording execution process parameters after each movement, this application can monitor the operating status and health of the footrest device in real time. This not only helps to promptly identify and eliminate potential faults, improving system reliability and safety, but also provides valuable data support for subsequent system maintenance, performance optimization, and accident analysis, thereby significantly enhancing the intelligence and maintainability of the entire active and passive safety collaborative system.

[0067] To address the technical problem that the passenger-side footrest fails to provide timely and effective foot support for occupants (especially smaller occupants) in a collision, leading to upward displacement of the legs and impact with the rigid structure below the dashboard, resulting in injury, this embodiment provides an innovative solution. This embodiment integrates the sensing module, central control module, and execution module in a coordinated active and passive safety manner. This allows for the dynamic generation and execution of footrest adjustment commands based on vehicle environmental data and occupant vital signs before a collision, overcoming the shortcomings of traditional solutions such as delayed protection and insufficient adaptability. This achieves improved local protection effectiveness in the foot area and precise body shape adaptation.

[0068] Example 2: In one embodiment, such as Figure 5 As shown, this embodiment provides an active passenger footrest adjustment system for coordinated active and passive safety, used to implement an active passenger footrest adjustment method for coordinated active and passive safety as mentioned in Embodiment 1. The system includes: The sensing module is used to collect vehicle environmental status data and occupant status data; The central control module is used to receive and process the data from the sensing unit, predict collision risks, and generate footrest adjustment instructions. The execution module is used to receive the adjustment command and drive the footrest device to complete the corresponding position and posture adjustment.

[0069] Furthermore, in this embodiment, the sensing module includes: The forward collision detection unit uses data fusion from millimeter-wave radar and a forward-looking camera. The Occupant Monitoring System (OMS) is used to identify occupant characteristics and output occupant body type classifications. The vehicle dynamic acquisition unit is used to acquire real-time motion status signals of the vehicle.

[0070] Specifically, the perception module is responsible for collecting information on the vehicle's internal and external environment and occupant status. This includes a forward collision sensing unit, an Occupant Status Monitoring (OMS) unit, and a vehicle dynamics acquisition unit, among which: The forward collision detection unit employs a fusion scheme of a 77GHz millimeter-wave radar and a forward-looking multi-function camera. This unit is installed behind the windshield and is used to detect the distance and relative speed of obstacles ahead in real time, and to calculate the estimated time of collision (TTC). The Occupant Status Monitoring Unit (OMS) integrates an infrared matrix sensor and an RGB camera (resolution: 1280x720) on the inside of the passenger-side A-pillar. This unit uses the YOLOv5 algorithm to recognize occupant facial features, posture, and seat height in real time, outputting an Occupant Classification (OCS) signal (e.g., encoding occupant body size as L-large, M-medium, S-small). Furthermore, the Occupant Classification (OCS) signal is set based on commonly used ergonomic data and crash test dummy models in the industry.

[0071] The vehicle dynamic acquisition unit directly acquires vehicle status signals, including vehicle speed, yaw rate, and longitudinal acceleration, via the CAN bus.

[0072] Furthermore, in this embodiment, the central control module includes a controller, a storage module, and a deep learning algorithm model running on the controller, used to assess collision risk, identify collision type, and query the adjustment strategy mapping table.

[0073] Specifically, the central control module is the core of the system's decision-making process, and it includes: The microcontroller is based on a dual-core Cortex-A7 architecture.

[0074] The algorithm and storage system utilizes a deep learning algorithm model trained on massive amounts of collision data, running within the microcontroller to process sensor fusion data and predict collision type and severity. Built-in FLASH memory stores preset adjustment strategy mapping tables for various collision scenarios.

[0075] The central control module receives data from all sensing modules, performs fusion calculations, and can distinguish between various collision modes such as head-on collision, offset collision, and small overlap collision, generating precise footrest adjustment commands.

[0076] Furthermore, in this embodiment, the execution module is an embedded footrest adjustment assembly, which includes: a base bracket fixed to the vehicle floor; a rotation drive assembly connected to the footrest and driving its rotation; and a translation drive assembly driving the footrest and the rotation drive assembly to translate along the front-rear direction of the vehicle.

[0077] Through the above technical solution, this embodiment enables the system to actively adjust the posture of the footrest before a collision occurs, effectively avoiding unexpected leg displacement caused by lack of foot support for occupants. This significantly improves the targeted protection capability for small-sized occupants and solves the protection lag problem caused by the passive triggering mechanism in the prior art. It provides a reliable technical path for strengthening local protection of the foot area for pure electric vehicles while controlling the amount of intrusion in the front enclosure.

[0078] Furthermore, the footrest is made of fiber-reinforced plastic with a non-slip surface and an embedded thin-film pressure sensor for monitoring foot contact pressure.

[0079] Specifically, the execution module is responsible for receiving control commands and performing mechanical actions, and it is fixed to the vehicle floor in the passenger footwell area by four M8x1.25 high-strength bolts. This assembly specifically includes: Base assembly: made of DC01 cold-rolled steel sheet by stamping and welding, and the surface is phosphated to improve corrosion resistance.

[0080] Rotary drive mechanism: Includes a high-speed brushless motor with a rated voltage of 12V and a rated torque of 3.5N·m. This motor drives a rotating shaft through a worm gear reducer with a transmission ratio of 50:1. This rotating shaft is fixedly connected to the tilting plate (foot rest), realizing the tilting motion of the foot rest.

[0081] Translation drive mechanism: Includes another high-speed brushless motor of the same specifications, which directly drives a ball screw with a lead of 5mm via a coupling. The screw nut is connected to a sliding base with a dovetail slider, which achieves high-precision forward and backward linear movement with the base assembly via a linear guide.

[0082] Inclined board (footrest) such as Figure 4 Made of PA66+30%GF material by injection molding, with dimensions of 300mm (length) x 250mm (width) x 3mm (thickness). Its surface is covered with a 2mm thick polyurethane foam anti-slip layer. An embedded flexible thin-film pressure sensor is used to monitor foot contact force in real time, providing overload protection.

[0083] By employing fiber-reinforced plastic (FRP) to manufacture the footrest device, the weight of the device is significantly reduced. This allows the actuator module to move the footrest to the preset protective posture more quickly and efficiently, thus shortening the response time and providing occupants with a valuable window of opportunity for protection. Simultaneously, the high strength and stiffness of FRP ensure that the footrest provides robust and stable support during a collision, effectively restraining the occupant's feet and preventing displacement or secondary injury. The anti-slip layer on the surface of the footrest further enhances the friction between the foot and the footrest, effectively preventing slippage of the occupant's feet during emergency braking or collision pre-tensioning, thereby ensuring that the footrest reliably provides support and restraint.

[0084] Example 3: This application provides a vehicle equipped with the aforementioned active passenger footrest adjustment system. This system, through a combined active and passive safety mechanism, actively adjusts the passenger footrest posture before a collision to provide targeted foot support. Specifically, the vehicle's perception module continuously collects external environmental data and occupant status data. The forward collision perception unit calculates the estimated collision time based on data fusion from millimeter-wave radar and a forward-facing camera. The occupant status monitoring unit identifies occupant facial features and posture and outputs body type classification signals. The central control module receives and processes the data. When the estimated collision time is less than or equal to 2.0 seconds and shows a decreasing trend, the relative speed is greater than or equal to 30 km / h, and the vehicle's longitudinal deceleration is greater than or equal to 0.3g, an advanced confirmation process is triggered. If the estimated collision time continues to decrease to less than or equal to 1.8 seconds, it is judged as a high-risk collision event, and a collision assessment is initiated based on the estimated collision time. The system queries the adjustment strategy mapping table based on type, relative speed, and occupant size, generating adjustment control commands that include preset target rotation angles and / or preset target translation distances. The execution module, embedded in the footrest adjustment assembly, has its base support fixed to the vehicle floor. The rotation drive component and translation drive component drive the footrest device to perform protective movements according to the commands. For example, in a 100% frontal collision and when the occupant is small, the footrest rotates to 58°±2° and moves backward by 40 mm. During the movement, a hybrid strategy combining position control and force control is adopted. After initial rapid positioning, fine-tuning is performed based on feedback from the internal thin-film pressure sensor. At the same time, the status of the drive motor is monitored to avoid stalling or temperature exceeding limits.

[0085] This embodiment integrates a combined active and passive safety system for the passenger-side footrest into the vehicle. Based on environmental predictions and occupant vital signs, it proactively adjusts the footrest posture before a collision, providing targeted foot support for occupants of different body types and effectively preventing leg impacts with rigid structures. Compared to traditional designs, this solution avoids protection lag issues. Through a pre-set adjustment strategy mapping table, it achieves precise adaptation between collision type and occupant body size, significantly improving protection effectiveness for smaller occupants.

[0086] Through the aforementioned technical solution, the vehicle can activate footrest adjustment during the collision risk prediction phase, moving the footrest device to a preset protective posture before a collision occurs. This provides restraint and support for the occupant's feet, effectively limiting the upward displacement of the legs and reducing the risk of impact with the structure below the dashboard. This reduces the probability of leg and foot injuries, meeting higher safety standards. After the collision risk is eliminated, the system controls the footrest device to return to its initial hidden position and performs self-diagnosis and parameter recording to ensure the reliability and maintainability of the device.

[0087] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for active adjustment of the passenger-side footrest in a coordinated active and passive safety system, characterized in that, include: ‌ Continuously monitor the vehicle's external environment and occupant status information; When a potential vehicle collision risk is predicted based on the environmental information, the occupant's vital signs information in the front passenger seat is obtained. Based on the potential vehicle collision risks and the occupant vital signs information, a matching control command for adjusting the passenger footrest is generated. According to the control command, the footrest device embedded in the passenger floor area is driven to perform a preset protective movement, moving it to a preset protective posture to provide restraint and support for the occupant's feet before a collision occurs.

2. The method according to claim 1, characterized in that: The continuous monitoring of the vehicle's external environment is accomplished through the vehicle's active safety system, which calculates collision risk assessment parameters, including the estimated collision time, based on the fusion perception data of millimeter-wave radar and a front camera. The acquisition of occupant vital signs information is achieved through an in-vehicle occupant status monitoring system. The occupant status monitoring system identifies the occupant's facial features and sitting posture, and outputs a classification signal representing the occupant's body type accordingly.

3. The method according to claim 2, characterized in that, The initial warning conditions for triggering the generation of the matching passenger footrest adjustment control command include: the expected collision time is less than or equal to 2.0 seconds and is decreasing, the relative speed is greater than or equal to 30 km / h, and the longitudinal deceleration of the vehicle is greater than or equal to 0.3g.

4. The method according to any one of claims 1 to 3, characterized in that, The generation of matching passenger footrest adjustment control commands includes: Advanced verification of potential vehicle collision risks is performed. When the predicted collision time is continuously reduced to less than or equal to 1.8 seconds, it is judged as a high-risk collision event. Based on the estimated collision type, estimated relative speed, and occupant vital signs information of the high-risk collision event, a preset adjustment strategy mapping table is queried to determine the adjustment target position information for the footrest device.

5. The method according to claim 4, characterized in that: The adjustment target position information includes at least the preset target rotation angle and / or preset target translation distance of the footrest; The preset adjustment strategy mapping table stores preset target rotation angle and target translation distance combinations corresponding to different collision types and different occupant body sizes.

6. The method according to claim 5, characterized in that, The preset adjustment strategy mapping table includes at least the following correspondences: When the estimated collision type is a 100% frontal collision and the occupant is small in size, the preset target rotation angle is 58°±2°, and the preset target translation distance is a rearward movement of (40±3) mm; When the estimated collision type is a 100% frontal collision and the occupant is of large size, the preset target rotation angle is 52° ± 2°, and no translational movement is required; When the estimated collision type is a 40% offset frontal collision and the occupant is of medium build, the preset target rotation angle is 55°±2°, and the preset target translation distance is a rearward movement of (30±3) mm; When the estimated collision type is a low overlap collision and the occupant is small in size, the preset target rotation angle reaches 60° and the preset target translation distance is a backward movement of (15±3) mm.

7. The method according to claim 1, characterized in that, The drive mechanism embedded in the passenger-side floor area, which is used to install a footrest, performs a preset protective movement, specifically: Control the rotation drive mechanism and translation drive mechanism in the footrest device to make the footrest rotate and / or translate linearly to reach the preset protective posture; The footrest device performs the preset protective movement using a hybrid control strategy that combines position control and force control: in the initial stage of movement, position control is mainly used to achieve rapid positioning; when approaching the target adjustment position, it switches to force control mode and performs fine-tuning positioning based on the feedback signal from the pressure sensor installed inside the footrest to ensure close support for the occupant's feet.

8. The method according to claim 7, characterized in that: The acceleration of the drive motor in the footrest device is limited by a preset maximum threshold. During the movement of the footrest device, the status parameters of its drive motor are monitored in real time. When an abnormal state, including stall or over-temperature, is detected, an emergency stop procedure is triggered.

9. The method according to claim 1, characterized in that, Also includes: After the potential vehicle collision risk is eliminated, the footrest device is controlled to return to its initial hidden position; Furthermore, after each motion is completed, a self-diagnosis is performed and the execution process parameters are recorded.

10. A passenger-side footrest active adjustment system for coordinated active and passive safety, used to implement the passenger-side footrest active adjustment method for coordinated active and passive safety as described in any one of claims 1 to 9, characterized in that, include: The sensing module is used to collect vehicle environmental status data and occupant status data; The central control module is used to receive and process the data from the sensing unit, predict collision risks, and generate footrest adjustment instructions. An execution module is used to receive the adjustment command and drive the footrest device to complete the corresponding position and posture adjustment; in: The perception module includes: a forward collision perception unit, which uses data fusion of millimeter-wave radar and a forward-looking camera; an occupant status monitoring unit, which identifies occupant characteristics and outputs occupant body type classification; and a vehicle dynamic acquisition unit, which acquires real-time motion status signals of the vehicle. The central control module includes a controller, a storage module, and a deep learning algorithm model running on the controller, used to assess collision risk, identify collision type, and query the adjustment strategy mapping table. The execution module is an embedded footrest adjustment assembly, which includes: a base bracket fixed to the vehicle floor; a rotation drive assembly connected to the footrest and driving its rotation; and a translation drive assembly that drives the footrest and the rotation drive assembly to translate along the front-rear direction of the vehicle.

11. The system according to claim 10, characterized in that, The footrest is made of fiber-reinforced plastic with a non-slip surface and an embedded thin-film pressure sensor for monitoring foot contact pressure.

12. A vehicle, characterized in that, The vehicle is equipped with an active adjustment system for the passenger footrest as described in any one of claims 10 to 11.

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