Safety protection system based on motor current change sensing of user status

Abstract

This invention relates to the field of safety protection technology and discloses a safety protection system based on sensing user status through motor current changes. The system includes: a motion parameter acquisition module for real-time acquisition of steering wheel angular velocity and torque data; a signal processing module for processing the acquired current, angular velocity, and torque signals; a status analysis module for analyzing the operating status of the steering wheel motor and determining whether the steering wheel is in a free-spinning state or a user-operated state by judging the difference between the steering wheel motor's current signal and a preset reference state; and a protection execution module for triggering a protection action when the steering wheel is in a free-spinning state. By employing a technical solution combining motor current changes and real-time status analysis, and using the Lyapunov exponent to determine the dynamic stability of the steering wheel combined with a bifurcation point detection algorithm, accurate identification of the free-spinning state and the user-operated state is achieved.

Description

Technical Field

[0001] This invention relates to the field of safety protection technology, specifically a safety protection system based on sensing user status through changes in motor current. Background Technology

[0002] In steering wheel simulators, especially high-precision steering wheel devices using direct-drive motors, the steering wheel is typically kept rotating even when unattended to realistically simulate vehicle operation. While this design enhances the realism of the simulation, it also introduces potential safety hazards. When the steering wheel is in a free-spinning state, accidental contact with a foreign object or person (such as a child's hand) could lead to injury. To detect this operation, current technologies primarily rely on simple threshold comparisons of motor current signals or statically set rules to determine the user's state.

[0003] Existing technologies often use fixed thresholds to detect changes in current signals to determine whether a user is operating the steering wheel. However, in practical applications, current signals exhibit significant fluctuations due to different operating scenarios (such as high-speed rotation and sharp turns) and external noise interference. Fixed thresholds cannot adapt to these complex variations and are prone to misjudgment. For example, under high load idling conditions, current fluctuations may be mistaken for user input. Therefore, existing solutions lack the ability to dynamically adapt to signal characteristics in complex scenarios.

[0004] In current signal processing, some existing technologies do not fully consider the impact of noise interference, typically only smoothing the signal through simple filtering. This method is prone to failure when there is a lot of high-frequency noise or transient interference, thus reducing the accuracy of the data. Signal noise not only affects the accuracy of status judgment but also further limits the reliability of protection mechanisms. Especially in abnormal signals caused by slight user contact with the steering wheel or external vibrations, existing methods cannot reliably distinguish between genuine user operation and noise signals. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a safety protection system based on sensing user status through changes in motor current. This system solves the problem that current signals exhibit significant fluctuations due to different operating scenarios (such as high-speed rotation and sharp turns) and external noise interference. Fixed thresholds cannot adapt to these complex changes and are prone to misjudgment.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a safety protection system based on sensing user status through changes in motor current, comprising:

[0007] The motion parameter acquisition module is used to acquire steering wheel angular velocity and torque data in real time;

[0008] The signal processing module is used to process the acquired current signal, angular velocity signal, and torque signal;

[0009] The status analysis module is used to analyze the operating status of the steering wheel motor and determine whether the steering wheel is in an idle state or a user operation state by judging the difference between the current signal of the steering wheel motor and the preset reference state.

[0010] The protection execution module is used to trigger protection actions when the steering wheel is in a free-spinning state, including reducing the motor torque output or stopping the steering wheel operation;

[0011] The control unit is used to analyze the operating status of the steering wheel motor and determine whether the steering wheel is in an idle state or a user operation state by judging the difference between the current signal of the steering wheel motor and the preset reference state.

[0012] When it is determined that the steering wheel is in a free-spinning state, the protection execution unit triggers a protection action, including reducing the motor torque output or stopping the steering wheel operation.

[0013] Preferably, the control unit analyzes the changing trend of the real-time current signal of the motor to determine whether the characteristic parameters of the real-time current signal match the reference parameters under idling conditions. The reference parameters include the current amplitude range, the rate of change range, and the current fluctuation frequency distribution.

[0014] Preferably, the control unit uses a filter to process the noise of the acquired real-time current signal. The filter includes a Kalman filter for dynamically estimating random noise to obtain an accurate current signal.

[0015] Preferably, the control unit determines the idling state or the user operation state by calculating the system's stability parameters. The stability parameters are calculated based on the Lyapunov index. When the stability parameter is negative, the steering wheel is determined to be in an idling state. When the stability parameter is positive, the steering wheel is determined to be in a user operation state.

[0016] Preferably, the control unit detects bifurcation points by analyzing the changing characteristics of the current signal, and determines that the steering wheel has entered the user operation state when the change in the current signal exceeds a preset threshold.

[0017] Preferably, the bifurcation point detection is achieved by calculating the change in response of the motor current signal to the external force input in real time. The calculation of the change in response is based on the relationship between the input signal and the current motor state in a preset model.

[0018] Preferably, the protection execution unit includes a gradual stop module and an emergency stop module. The gradual stop module achieves a slow stop of the steering wheel by gradually reducing the output torque of the motor, and the emergency stop module achieves a rapid stop of the steering wheel by cutting off the power supply to the motor.

[0019] Preferably, the gradual stopping module reduces the output torque of the steering wheel motor, and the change in torque value is exponential with time.

[0020] Preferably, the control unit uses a dynamic update mechanism to adjust the reference parameters of the idling state, and optimizes the reference parameters based on real-time operating data to adapt to different environments and equipment states.

[0021] Preferably, the control unit dynamically adjusts the threshold parameters for bifurcation point detection and the determination conditions for the Lyapunov index through a reinforcement learning algorithm to adapt to various user operating habits and steering wheel operation scenarios.

[0022] This invention provides a safety protection system based on sensing user status through changes in motor current. It offers the following advantages:

[0023] 1. This invention employs a technical solution combining motor current variation and real-time state analysis. It determines the dynamic stability of the steering wheel using the Lyapunov exponent and incorporates a bifurcation point detection algorithm, achieving accurate identification of idling and user operation states. This results in rapid response to different state transitions and reduced misjudgments. Compared to existing technologies that rely solely on fixed thresholds to detect current changes, this invention solves the problems of frequent misjudgments and poor adaptability.

[0024] 2. This invention employs Kalman filtering and dynamic feature extraction techniques. Through real-time denoising and feature calculation of the current signal, it ensures the accuracy and stability of the signal data, further improving the reliability of subsequent state analysis. Compared with existing technologies that only perform simple signal sampling, this invention solves the shortcomings of data instability and low judgment accuracy caused by noise interference.

[0025] 3. This invention, through the coordinated design of two protection mechanisms—gradual shutdown and emergency shutdown—achieves flexible response and rapid protection against abnormal steering wheel conditions, achieving a technical effect that balances safety and user experience. Compared to existing technologies with single shutdown mechanisms and delayed responses, this invention solves the safety hazards and operational discontinuity issues that may arise from the inertial rotation of the steering wheel.

[0026] 4. This invention employs a technical solution of dynamically adjusting the protection threshold and scene adaptive optimization. It can adjust the triggering conditions of the protection mechanism according to the characteristics of the steering wheel under different operating scenarios (such as high load and high-speed rotation), achieving the technical effect of reducing false triggers and improving system applicability. Compared to the lack of flexibility in the protection mechanism of existing technologies, this invention solves the problem of being unable to adapt to complex scene changes. Attached Figure Description

[0027] Figure 1 This is a system framework diagram of the present invention. Detailed Implementation

[0028] The technical solutions in 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, and 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] Please see the appendix Figure 1 This invention provides a safety protection system based on sensing user status through changes in motor current, comprising:

[0030] The current acquisition module is used to acquire the real-time current signal of the motor.

[0031] The motion parameter acquisition module is used to acquire steering wheel angular velocity and torque data in real time;

[0032] The signal processing module is used to process the acquired current signal, angular velocity signal, and torque signal;

[0033] The status analysis module is used to analyze the operating status of the steering wheel motor and determine whether the steering wheel is in an idle state or a user operation state by judging the difference between the current signal of the steering wheel motor and the preset reference state.

[0034] The protection execution module is used to trigger protection actions when the steering wheel is in a free-spinning state, including reducing the motor torque output or stopping the steering wheel operation;

[0035] The control unit is used to analyze the operating status of the steering wheel motor and determine whether the steering wheel is in an idle state or a user operation state by judging the difference between the current signal of the steering wheel motor and the preset reference state.

[0036] When it is determined that the steering wheel is in a free-spinning state, the protection execution unit triggers a protection action, including reducing the motor torque output or stopping the steering wheel operation.

[0037] Implementation Method 1: System Architecture and Components

[0038] This invention provides a safety protection system based on sensing user status through changes in motor current. The system consists of the following core modules: a current acquisition module, a motion parameter acquisition module, a signal processing module, a status analysis module, and a protection execution module. These modules work together to determine the user's operating status by collecting real-time steering wheel operation data and triggering a safety protection mechanism under specific circumstances.

[0039] Current acquisition module

[0040] This module is installed on the power supply circuit of the steering wheel motor and is mainly used for real-time acquisition of three-phase current signals. The current acquisition module includes a high-precision, fast-response current sensor that converts the acquired current signal into a digital signal for transmission to the signal processing module. The module's high sampling rate effectively captures current fluctuations, avoiding misjudgments caused by transient changes.

[0041] Motion parameter acquisition module

[0042] The motion parameter acquisition module uses built-in angular velocity and torque sensors to obtain the angular velocity and real-time torque values ​​of the steering wheel. The angular velocity sensor records changes in the steering wheel's rotational speed. The torque sensor detects the load torque output by the steering wheel motor. Together, they provide crucial motion parameters for subsequent analysis modules.

[0043] Signal processing module

[0044] The signal processing module performs preliminary processing on the current signal and motion parameters. It incorporates efficient filtering algorithms, such as Kalman filters, to remove noise interference and extract useful signals. By calculating the mean, frequency distribution, and amplitude range of current fluctuations in real time, the signal processing module generates feature data, providing accurate input to the state analysis module.

[0045] Status Analysis Module

[0046] The state analysis module is the core of the system. This module uses built-in algorithms to perform in-depth analysis of real-time current signals, including a Lyapunov exponent determination algorithm and a bifurcation point detection algorithm. The Lyapunov exponent is used to determine the current stability of the motor. When the calculation result is negative, it indicates that the steering wheel is in a free-spinning state; when the exponent value is positive, it indicates that the user is applying external force. The bifurcation point detection further captures the input signal of sudden external force, and by comparing the current change with a preset threshold, it confirms whether the system has entered an operating state.

[0047] Protect execution module

[0048] The protection execution module directly controls the steering wheel's operating status. When the status analysis module determines that the steering wheel is in an idle state, the protection execution module activates the protection mechanism. The protection actions include two types: gradual shutdown and emergency shutdown. Gradual shutdown ensures that the steering wheel stops smoothly by gradually reducing the motor's output power. Emergency shutdown is activated when there is high torque idle or an abnormal current is detected. It directly cuts off the motor power supply and triggers the mechanical braking device to prevent the steering wheel from continuing to rotate due to inertia.

[0049] Implementation Method 2: Operation Flow

[0050] This system begins operation immediately after the steering wheel is turned on. Its operation process consists of the following stages:

[0051] During the data acquisition phase, the system's current acquisition module and motion parameter acquisition module collect the motor's three-phase current, steering wheel angular velocity, and torque signals in real time. These data are transmitted to the signal processing module through a digital interface. The data acquisition phase operates seamlessly, with a sampling frequency set to 1kHz, which can capture subtle changes in the motor's operation.

[0052] Data processing stage

[0053] After receiving the acquired data, the signal processing module first performs noise reduction. The Kalman filter dynamically estimates the signal, eliminates high-frequency interference and random noise, and extracts the true signal characteristics. The processed data includes important parameters such as current amplitude, fluctuation range, and frequency distribution, which are then distributed to the state analysis module.

[0054] State analysis phase

[0055] The state analysis module compares and analyzes the processed current signal and motion parameters against a preset idling reference model. The module determines the state through the following steps:

[0056] First, calculate the Lyapunov index. If the index value is less than zero, the steering wheel is stable, and it can be preliminarily determined to be in a state of freewheeling.

[0057] Secondly, a bifurcation point detection is performed to check whether the change in the current signal exceeds a set threshold. If the change is small, it indicates insufficient external force input, further confirming a freewheeling state; if the change is large, it indicates that the user is operating the steering wheel.

[0058] Finally, the judgment result is transmitted to the protection execution module.

[0059] Protection Execution Phase

[0060] After the status analysis module determines that the steering wheel is in a free-spinning state, the protection execution module activates the protection mechanism. The system selects an appropriate protection action based on the duration of the free-spinning and the characteristics of current changes.

[0061] Gradual shutdown: If the steering wheel continues to idle for more than 3 seconds without detecting abnormal current, the system gradually reduces the motor output power, allowing the steering wheel to stop rotating smoothly.

[0062] Emergency Stop: When high torque idling or abnormal current is detected, the motor power supply is directly cut off, triggering the mechanical braking device. This method can quickly stop the steering wheel within milliseconds, avoiding potential safety hazards.

[0063] Implementation Method 3: Core Principles and Beneficial Effects

[0064] Core Principles

[0065] The system senses the user's status based on the dynamic changes in the motor current signal. During user operation, the current signal changes significantly due to external force input, exhibiting nonlinear behavior. The system determines the user's operation behavior by analyzing the characteristic parameters of the current signal (such as amplitude, frequency, and fluctuation rate) in real time.

[0066] The stability of the steering wheel was analyzed using the Lyapunov exponent. Under idling conditions, the system is a stable attractor with a negative exponent value; when the user operates the system, the attractor characteristics shift, and the exponent value becomes positive.

[0067] Bifurcation point detection captures sudden current changes, further improving the system's judgment accuracy.

[0068] Beneficial effects include improved accuracy: Through real-time signal acquisition and complex algorithm analysis, the system can accurately determine the operating status of the steering wheel, effectively avoiding misjudgments.

[0069] Enhanced safety: The safety mechanism is quickly triggered when the steering wheel is idling to prevent injury to the user (especially children) due to the inertial rotation of the steering wheel.

[0070] Adaptable to complex scenarios: The system's bifurcation point detection and dynamic benchmark update mechanism enable it to adapt to different game scenarios (such as sharp turns, high torque output, etc.).

[0071] Stable operation: The Kalman filter removes noise interference, ensuring data reliability. The gradual shutdown mechanism further prevents steering wheel reaction force issues caused by sudden shutdown.

[0072] In this embodiment, the current acquisition module mainly consists of a current sensor, an analog-to-digital converter circuit, and a signal transmission interface. Its core function is to acquire the three-phase current signal (I0) of the motor. u I v I w It converts and transmits signals.

[0073] Typically, the three-phase current signal of a motor is a high-frequency dynamic signal, and its amplitude and frequency change with the motor load, external force input, and motor speed. To ensure data accuracy, the current acquisition module uses a high-precision Hall effect current sensor. This sensor can quickly respond to current changes within its linear range, providing a high dynamic range and low-noise output signal.

[0074] Specifically, the linear output range of the sensor is set to ±30A, which can cover the current amplitude that may occur during the operation of the steering wheel direct drive motor. Alternatively, the signal output of the current sensor is directly connected to the analog-to-digital converter (ADC). The ADC uses a 12-bit high-precision ADC with a sampling frequency set to 1kHz to capture rapidly changing current signals in real time. The selection of the sampling frequency is based on the operating characteristics of the steering wheel, effectively capturing transient current fluctuations while avoiding the computational burden caused by excessively high sampling frequencies. Specifically, the current acquisition module acquires and processes the three-phase current signal through the following steps: First, the current sensor measures the three-phase current I of the motor. u I v I w Each phase current signal is converted into an analog voltage signal and output to an analog-to-digital converter (ADC). The ADC receives the analog signal from the sensor and converts it into a digital signal, forming discrete current data. This data is updated 1000 times per second, and the converted data is transmitted to the signal processing module via a digital interface. The digital interface supports SPI (Serial Peripheral Interface) communication, ensuring the stability and accuracy of high-frequency signal transmission.

[0075] In some embodiments, the current acquisition module also has a calibration function to eliminate the influence of sensor nonlinearity errors and circuit noise on the measurement results. Generally, the calibration process is completed before system startup. Specifically, the motor is placed in a stationary state, and the reference offset values ​​of the three-phase currents are recorded and stored in the module's memory. After calibration, all subsequently acquired current data will be corrected in real time based on the reference offset values, thereby improving measurement accuracy.

[0076] In one possible implementation, the current acquisition module can also extract characteristic parameters such as amplitude, mean, and ripple rate based on the transient waveform characteristics of the current. Specifically, the digital signal after analog-to-digital conversion can calculate the following characteristics using a built-in algorithm:

[0077] Current amplitude, that is, the instantaneous magnitude of the current at the current moment;

[0078] Average current is calculated by using a sliding time window to determine the average current value over a specific time range.

[0079] Fluctuation rate is the rate at which a current signal changes per unit time.

[0080] These characteristic parameters provide data support for subsequent signal processing modules, further enhancing the system's ability to perceive the user's operating status.

[0081] As an extended implementation, the current acquisition module can also handle high-frequency noise and low-frequency interference during motor operation. Noise sources include power supply fluctuations, external electromagnetic interference, and the nonlinear characteristics of the motor itself. To filter out these interferences, some embodiments embed hardware filters, specifically a first-order low-pass filter and a band-pass filter. The low-pass filter suppresses high-frequency noise signals, with its cutoff frequency set to 1kHz; the band-pass filter preserves the effective frequency band of the current signal, such as the current components within the range of 100Hz to 500Hz. During motor operation, the acquired current signal can be modeled using the following relationship to describe its three-phase characteristics.

[0082] I u +I v +I w =0

[0083] This constraint reflects the basic characteristic of three-phase symmetry in a motor and can be used for signal verification and anomaly detection during system operation. To further illustrate the operating principle of the current acquisition module, consider the following example: Assume the motor is operating normally with a current output torque of 3 Nm and a steering wheel speed of 100 rpm. The average three-phase currents under idling conditions are as follows: I u =2.0A, I v =-1.5A, I w = -0.5A. If the user applies external force to rotate the steering wheel counterclockwise, causing the motor to enter a stall state, the instantaneous amplitude of the three-phase current may increase significantly, for example, I. u =4.5A, I v =-3.0A, I w = -1.5A. At this point, the current acquisition module can quickly capture these changes, providing real-time data support for the subsequent state analysis module.

[0084] In this embodiment, the core function of the signal processing module is to perform noise reduction, feature extraction, and parameter correction on the acquired signal. Generally, the fluctuation of the current signal is affected by both the motor's operating state and external interference, containing many invalid or unstable components. To accurately extract user operation features, this module processes the current signal, angular velocity signal, and torque signal separately. Specifically, the current signal first undergoes noise reduction processing using a Kalman filter. The Kalman filter can dynamically estimate the true value of the signal, filter out high-frequency interference, and effectively suppress random noise. The state update formula for the Kalman filter is:

[0085]

[0086] in, It is the state estimate at time k; z k H is the sampled observation; H is the transformation matrix between state and observation; K k This is the Kalman gain, and its calculation formula is:

[0087]

[0088] In this formula, P k|k-1 Here, is the prediction covariance matrix, and R is the observation noise covariance matrix. In one possible implementation, the system extracts various feature parameters from the filtered current signal, specifically including current amplitude, current fluctuation rate, and current frequency distribution. The current fluctuation rate is calculated using the following formula:

[0089]

[0090] In this formula, ΔI represents the instantaneous change in current, and Δt represents the sampling interval. Alternatively, the processing flow for angular velocity and torque signals is similar to that for current signals. The angular velocity signal reflects the dynamic characteristics of steering wheel rotation, and its characteristic parameters include the mean and instantaneous change in rotation speed. The torque signal is used to capture the output characteristics of the steering wheel motor under different loads. The system calculates the mean and fluctuation range of the torque signal through a time sliding window to describe the motor's operating state.

[0091] In some embodiments, the signal processing module also includes a reference offset correction function. Typically, the initial current signal of the motor has a static offset value, which may be caused by hardware drift or power supply fluctuations. This module uses data collected during idling to correct the initial value of the current signal in real time, ensuring the accuracy of the characteristic parameters. For example, assuming the initial offset values ​​of the three-phase current signals are I... u0 =0.2A, I v0 =-0.1A, I w0 = -0.1A. During operation, the system will automatically subtract these offset values ​​to obtain the corrected current signal. As an extension, this module can also perform real-time detection and rejection of abnormal signals. For example, when the current signal shows obvious jumps or abnormal frequency distribution, the system will automatically mark the signal as invalid data and perform compensation processing through interpolation algorithms. This function further enhances the system's adaptability to sudden interference.

[0092] To more clearly illustrate the role of the signal processing module, consider the following scenario: Assume the steering wheel motor is in a free-running state, and the three-phase current signals collected are I... u =2.1A, I v =-1.6A, I w = -0.5A, after filtering and correction by the signal processing module, the system obtains the correction value I. u =2.0A, I v =-1.5A, I w = -0.5A, the acquired signal changes after the user applies an external force, for example, I u =4.5A, I v =-3.0A, I w =-1.5A, the module extracts the characteristics of the external force input by calculating the fluctuation rate and frequency distribution of these signals, providing support for subsequent state analysis.

[0093] In this embodiment, the signal processing module can extract key information from the steering wheel operation data with high precision while effectively suppressing noise interference. This not only ensures the reliability of the data input but also lays a solid foundation for the subsequent state analysis module. The multiple processing algorithms embedded in the module give it strong robustness, enabling it to adapt to the complex data requirements of different operating scenarios.

[0094] In this embodiment, the function of the state analysis module is to comprehensively judge the processed real-time data to identify whether the steering wheel is in a free-wheeling state or a user-operated state. "Under normal circumstances, the current signal in a free-wheeling state exhibits stable fluctuations, with its range and frequency of change highly consistent with a preset benchmark model. However, when the user applies external force, the current signal exhibits nonlinear abrupt changes, and the angular velocity and torque parameters also change significantly. The state analysis module achieves accurate state determination by calculating stability parameters and detecting signal abrupt changes. Specifically, the operation of the state analysis module includes the following key steps: First, the module calculates the Lyapunov exponent of steering wheel operation based on the real-time current signal. This exponent is used to measure the dynamic stability of the system, and its calculation formula is:"

[0095]

[0096] Where λ is the Lyapunov exponent, used to characterize the system’s sensitivity to initial state disturbances, δx(0) is the small deviation between initial states, and δx(t) is the state deviation at time t. In one possible implementation, if λ<0, the system tends to be a stable attractor, and is judged to be in an idle state; if λ>0, the system exhibits chaotic characteristics, indicating that the steering wheel is being subjected to external force input from the user.

[0097] To further improve the accuracy of the judgment, the module performs bifurcation point detection on the changing trend of the current signal. The core of bifurcation point detection is to capture nonlinear abrupt changes in the current signal. The detection method is to calculate whether the change in real-time current exceeds a preset threshold. The specific formula is as follows:

[0098]

[0099] Where ΔI is the change in current; u c It is the bifurcation point threshold of the external force input, and f(x,u) represents the current dynamic model of the system. As an option, when ΔI exceeds the preset threshold, the module determines that the steering wheel will transition from the idle state to the user operation state; if the change is small, the determination of the idle state is maintained.

[0100] In some embodiments, the state analysis module also incorporates the variation characteristics of angular velocity and torque signals to further confirm the judgment result. Specifically, the module analyzes the instantaneous rate of change of the angular velocity signal. Generally, angular velocity changes slowly and without significant abrupt changes during idling; however, during user operation, the rate of change of angular velocity increases significantly. The module calculates the rate of change of angular velocity using a time sliding window.

[0101]

[0102] Among them, v ω Δω is the rate of change of angular velocity; Δω is the change of angular velocity within the time interval Δt.

[0103] For the torque signal, the module analyzes whether its fluctuation amplitude exceeds the reference range. Specifically, the module calculates the deviation between the fluctuation range of the torque signal and the preset reference range. If the deviation exceeds a set threshold, it further supports the determination of the user's operating status.

[0104] To illustrate the operation of the state analysis module more intuitively, consider the following scenario: Assume the steering wheel motor is in a free-running state. The real-time calculated Lyapunov exponent is -0.2, and the current change detected at the bifurcation point is 0.8A, both below the set bifurcation point threshold of 1.0A. At this point, the module determines the steering wheel is in a free-running state. When the user applies external force to rotate the steering wheel, the real-time current signal's bifurcation point change increases to 1.5A, exceeding the preset bifurcation point threshold, and the calculated Lyapunov exponent becomes 0.5, indicating the system has entered a chaotic state. This is combined with the rate of change of angular velocity v. ω The significant increase of 15° / s and the abnormal deviation in the amplitude of the torque signal fluctuation led the module to ultimately determine that the steering wheel was in a user-operated state.

[0105] Among some possible improvements, the state analysis module can introduce a multi-model comparison mechanism to improve the judgment accuracy in complex scenarios. For example, for different game scenarios (such as high-speed turning, vibrating road surfaces), the module can load a baseline model corresponding to the scenario and switch models in real time for state analysis. As described in this embodiment, the state analysis module achieves high-precision user operation recognition through multi-parameter judgment, and can adapt to the dynamic changes of various complex scenarios, providing a reliable basis for triggering subsequent protection mechanisms. The module is reasonably designed and fully functional, providing core support for the steering wheel safety protection system.

[0106] Step S4 is the protection mechanism triggering and execution phase. In this phase, the system, based on the judgment results of the status analysis module and combined with the preset protection logic, initiates the corresponding protection action. The protection mechanism includes two modes: gradual shutdown and emergency shutdown. The specific action depends on the current operating status of the steering wheel and the degree of abnormality. The design of this phase aims to ensure that the steering wheel responds quickly when no one is operating it or when there is an abnormality, while avoiding unnecessary interference with normal user operation.

[0107] In this embodiment, the protection execution module triggers appropriate protection actions based on the judgment results provided by the state analysis module. Generally, when the steering wheel is in a free-spinning state for a duration exceeding a set threshold, the system will prioritize activating the gradual shutdown mode. In cases of high torque free-spinning or abnormal current exceeding limits, the system directly triggers the emergency shutdown mode to quickly stop the steering wheel. Specifically, the gradual shutdown mode gradually reduces torque by controlling the motor's output power, achieving a smooth stop of the steering wheel. Generally, the motor's torque change exhibits an exponential decay relationship with time, and its control formula is:

[0108] T(t) = T0·e -αt

[0109] Where T(t) is the motor output torque at the current moment, T0 is the initial torque when the gradual stop is triggered; α is the torque attenuation coefficient, used to control the attenuation speed. As an option, the attenuation coefficient α can be dynamically adjusted according to the steering wheel's operating state. For example, in the low-speed idling state, the value of i is smaller to ensure that the steering wheel stops slowly; while in the high-speed idling state, the value of α is appropriately increased to reduce the inertial effect of the steering wheel as soon as possible.

[0110] In some embodiments, the emergency stop mode is used to address more serious safety risks, such as continuous high-torque idling or transient current exceeding a preset limit. The emergency stop is implemented in two parts: cutting off the motor power supply and triggering the mechanical brake. Generally, the system can trigger an emergency stop upon detecting any of the following conditions:

[0111] The current amplitude exceeds the rated range of the motor (e.g., ±30A).

[0112] The current fluctuation rate has increased abnormally, exceeding the set threshold.

[0113] The Lyapunov index fluctuates repeatedly in a short period of time, indicating that the steering wheel is unstable.

[0114] Specifically, the emergency stop instantly cuts off the motor power supply, immediately stopping the power output to the steering wheel. Simultaneously, the system triggers a built-in mechanical braking device, forcibly locking the steering wheel in its current position. This dual protection mechanism effectively prevents the steering wheel from continuing to rotate due to inertia, thus avoiding potential damage.

[0115] In some embodiments, to improve the accuracy of protection actions, the protection execution module also incorporates real-time operational data for auxiliary judgment. For example, when the duration of idling approaches a set threshold, the system will reduce the motor output power in advance to reduce the impact force when triggering the protection action. Specifically, the module can adjust the shape of the deceleration curve according to the rate of change of real-time angular velocity. For example, if the angular velocity change is large, the deceleration curve tends to be steep; if the angular velocity change is small, the deceleration curve tends to be gentle.

[0116] In another possible implementation, the protection execution module also dynamically optimizes the triggering conditions for protection actions. For example, when an abnormal current change is detected but the torque signal does not exceed the limit, the system can choose not to trigger the protection temporarily, but instead perform a short-term power reduction operation on the motor and reassess the subsequent state. This design can effectively reduce the frequency of false protection triggers while ensuring the continuity of the user experience.

[0117] Here's an example illustrating the specific execution process of the protection mechanism: Assume the steering wheel is unattended, the Lyapunov exponent calculated in real-time is -0.5, and the idling duration has reached the set threshold of 5 seconds. At this point, the system triggers a gradual shutdown mode, progressively reducing the motor's output torque. If the initial torque is 3 Nm and the attenuation coefficient α is set to 0.2, then after 2 seconds, the motor torque will decrease to 1.1 Nm, and the steering wheel will stop rotating. Now, consider another scenario: the user accidentally touches the steering wheel, causing the current to surge instantaneously to 35 A, and simultaneously, the torque fluctuation amplitude abnormally increases. The system immediately determines this as an emergency and triggers the emergency shutdown mode. Simultaneously with cutting off the motor power supply, the mechanical braking device quickly locks the steering wheel position; the entire process is completed within milliseconds.

[0118] Through the above design, this embodiment achieves rapid response and flexible control of the protection mechanism. The protection execution module effectively addresses safety risks under different operating conditions through a dual protection mode of gradual shutdown and emergency shutdown. The module's design not only ensures the safety of the steering wheel in abnormal conditions but also considers the smooth user experience. Combined with dynamic optimization functions, the module possesses strong adaptability and reliability, providing an important guarantee for the overall safe operation of the system.

[0119] In this embodiment, the core of the protection execution module is to achieve rapid triggering and flexible execution of protection actions. Normally, when the steering wheel is in a free-spinning state, the system gradually reduces the motor output power, gradually stopping the steering wheel. In emergency situations (such as abnormal current over-limit or high torque free-spinning), the module directly triggers an emergency stop, forcibly stopping the steering wheel rotation and locking its position. This dual protection mechanism effectively reduces the risks caused by steering wheel inertia and ensures timely and accurate response. Specifically, the gradual stop gradually reduces the motor output torque, causing the steering wheel to stop smoothly. The torque change curve satisfies the following relationship:

[0120] T(t) = T0·e -αt

[0121] Where T(t) is the motor output torque at the current moment, T0 is the initial torque when the protection is triggered, and α is the torque attenuation coefficient, which determines the rate of attenuation. As an option, the attenuation coefficient α can be dynamically adjusted according to the steering wheel's operating state. For example, when the steering wheel is idling at high speed, the value of α is larger, which can quickly reduce the output power in a short time; when idling at low speed, the value of α is appropriately reduced to ensure smooth deceleration of the steering wheel. This dynamic adjustment mechanism enhances the flexibility and adaptability of the protection action.

[0122] In some embodiments, the protection execution module also supports an emergency stop mode to deal with high-risk abnormal situations. Generally, an emergency stop is triggered by the following conditions: the amplitude of the real-time current signal exceeds the preset upper limit, the current fluctuation rate increases significantly, indicating that the steering wheel may be subject to external interference, the Lyapunov exponent remains positive, and the bifurcation point detection result of the current signal exceeds the limit.

[0123] Specifically, the emergency stop involves two parts: First, the module immediately cuts off the motor power supply via the control unit, stopping all power output to the steering wheel. Second, the module triggers the mechanical braking device to lock the steering wheel in its current position. This dual mechanism effectively prevents the steering wheel from continuing to rotate due to inertia, thereby protecting the safety of the user and the equipment.

[0124] As one possible implementation, the protection execution module can further optimize protection actions by combining real-time angular velocity and torque data. For example, before triggering an emergency stop, the module can analyze the instantaneous rate of change of angular velocity and the fluctuation amplitude of torque to determine the actual operating state of the steering wheel. If the angular velocity change is small but the current is abnormal, the module can choose to reduce the motor output power instead of immediately cutting off power. This design reduces interference with the user experience while ensuring safety. In another possible implementation, the module also supports a short-term recovery function to quickly restart the steering wheel after triggering a gradual stop. Generally, after the gradual stop is completed, the module will detect whether the user has reapplied external force. If the changes in angular velocity and current signals indicate that the user is operating the steering wheel, the module will restart the motor in a low-power mode to ensure the continuity of the system. The following example illustrates the specific operation process of the protection execution module: Assuming the steering wheel is unattended, the real-time calculated Lyapunov exponent is -0.3, and the current signal bifurcation point detection result is 0.7A, which does not exceed the preset threshold of 1.0A. At this point, the system triggers a gradual shutdown mode, progressively reducing the motor's output power. The initial torque is 3 Nm, with a decay coefficient α = 0.2. After approximately 2 seconds, the torque gradually decreases to 1 Nm, and the steering wheel comes to a smooth stop. Now, assuming another scenario, if the user accidentally touches the device while the steering wheel is spinning freely at high speed, causing the current signal to surge to 35A, exceeding the motor's rated limit of 30A, and simultaneously, the instantaneous rate of change of angular velocity increases to 20° / s, the system immediately determines an emergency state, triggering the emergency shutdown mode, cutting off the motor power supply and locking the steering wheel. The entire process is completed within 10 milliseconds, effectively preventing equipment damage and user injury.

[0125] In some embodiments, the protection execution module also supports dynamic optimization of the triggering conditions for protection actions. For example, when the system is in a high-load scenario of a game (such as high-speed turns or vibrating road sections), the module can appropriately increase the current threshold and fluctuation rate limit for emergency shutdown, thereby reducing the possibility of false triggering.

[0126] Through the above design, the protection execution module can flexibly respond to different operating states and abnormal situations. Its combined use of gradual shutdown and emergency shutdown modes ensures both the flexibility and adaptability of the protection actions, as well as rapid response in high-risk scenarios. The module's design provides crucial support for the stable operation of the steering wheel safety protection system.

[0127] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A safety protection system based on sensing user status through changes in motor current, characterized in that, include: The current acquisition module is used to acquire the real-time current signal of the motor. The motion parameter acquisition module is used to acquire steering wheel angular velocity and torque data in real time; The signal processing module is used to process the acquired current signal, angular velocity signal, and torque signal; The status analysis module is used to analyze the operating status of the steering wheel motor and determine whether the steering wheel is in an idle state or a user operation state by judging the difference between the current signal of the steering wheel motor and the preset reference state. The protection execution module is used to trigger protection actions when the steering wheel is in a free-spinning state, including reducing the motor torque output or stopping the steering wheel operation; The control unit is used to analyze the operating status of the steering wheel motor and determine whether the steering wheel is in an idle state or a user operation state by judging the difference between the current signal of the steering wheel motor and the preset reference state. When it is determined that the steering wheel is in a free-spinning state, the protection execution module triggers a protection action, including reducing the motor torque output or stopping the steering wheel operation; When the steering wheel is spinning freely for a period of time exceeding a set threshold, the system will first activate the gradual shutdown mode. In the case of high torque spinning or abnormal current exceeding the limit, the system will directly trigger the emergency shutdown mode to quickly stop the steering wheel from spinning.

2. The safety protection system based on sensing user status through motor current changes according to claim 1, characterized in that, The control unit analyzes the changing trend of the real-time current signal of the motor to determine whether the characteristic parameters of the real-time current signal match the reference parameters under idling conditions. The reference parameters include the current amplitude range, the rate of change range, and the current fluctuation frequency distribution.

3. The safety protection system based on sensing user status through motor current changes according to claim 1, characterized in that, The control unit uses a filter to process the noise in the acquired real-time current signal. The filter includes a Kalman filter, which is used to dynamically estimate random noise to obtain an accurate current signal.

4. The safety protection system based on sensing user status through motor current changes according to claim 1, characterized in that, The control unit determines the idling state or the user operation state by calculating the system's stability parameters. The stability parameters are calculated based on the Lyapunov index. When the stability parameter is negative, the steering wheel is determined to be in an idling state. When the stability parameter is positive, the steering wheel is determined to be in a user operation state.

5. The safety protection system based on sensing user status through motor current changes according to claim 1, characterized in that, The control unit detects bifurcation points by analyzing the changing characteristics of the current signal. When the change in the current signal exceeds a preset threshold, it determines that the steering wheel has entered the user operation state.

6. The safety protection system based on sensing user status through motor current changes according to claim 5, characterized in that, The bifurcation point detection calculates the change in response of the motor current signal to the external force input in real time. The calculation of the change in response is based on the relationship between the input signal and the current motor state in a preset model.

7. The safety protection system based on sensing user status through motor current changes according to claim 1, characterized in that, The protection execution module includes a gradual shutdown module and an emergency shutdown module. The gradual shutdown module achieves this by gradually reducing the motor output torque. The steering wheel is now slowly stopping. The emergency stop module achieves rapid stopping of the steering wheel by cutting off the power supply to the motor.

8. The safety protection system based on sensing user status through motor current changes according to claim 7, characterized in that, The gradual stopping module reduces the output torque of the steering wheel motor, allowing the steering wheel to stop smoothly. The change in torque data is exponential with time.

9. The safety protection system based on sensing user status through motor current changes according to claim 1, characterized in that, The control unit uses a dynamic update mechanism to adjust the baseline parameters in the idling state, and optimizes the baseline parameters based on real-time operating data to adapt to different environments and equipment states.

10. The safety protection system based on sensing user status through motor current changes according to claim 1, characterized in that, The control unit dynamically adjusts the threshold parameters for bifurcation point detection and the determination conditions for the Lyapunov index through reinforcement learning algorithms to adapt to various user operating habits and steering wheel operation scenarios.

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