Optical relay power consumption control system and method based on fixed time sliding mode for vehicle

Abstract

The application discloses a vehicle light relay power consumption control system and method based on fixed time sliding mode, relates to the technical field of vehicle power consumption control, and comprises a state acquisition module which acquires a target state, a real-time feedback state and an aging state parameter of a vehicle light relay; a sliding mode surface calculation module which calculates and generates a sliding mode surface state variable based on the target state and the real-time feedback state; a sliding mode control module which keeps a gain amplitude coefficient constant and dynamically adjusts a fractional power parameter based on the aging state parameter, obtains an adjusted fixed time sliding mode reaching law, and calculates and generates a continuous control quantity in combination with the sliding mode surface state variable; and a drive output module which generates discrete drive control signals based on the continuous control quantity and outputs the discrete drive control signals to the vehicle light relay. The application introduces an aging state parameter sensing device light decay, dynamically adjusts a fractional power parameter to change system convergence curvature, and improves the response speed, power consumption performance and operation reliability of the vehicle light relay under long-term service.

Description

Technical Field

[0001] This application relates to the field of vehicle power consumption control technology, and in particular to a power consumption control system and method for automotive opto-relays based on fixed-time sliding mode. Background Technology

[0002] Due to their advantages such as complete electrical isolation between high and low voltage, no contact arcing, and long service life, photorelays have become key actuators in safety systems such as battery management systems and high-voltage distribution boxes in new energy vehicles. Automotive-grade applications require them to meet hard constraints on fixed-time conduction and turn-off sequences, low-power control requirements, and functional safety specifications within a wide temperature range of -40℃ to 125℃ and a full lifespan of 15 years or 200,000 kilometers.

[0003] Fixed-time sliding mode control (RTM) has become the mainstream solution for power consumption control of automotive photoelectric relays due to its advantages of preset upper bound convergence time and independence from initial system state and external disturbances. However, existing solutions have technical limitations. To cover conduction reliability under extreme low temperature and aging end conditions, existing solutions generally adopt a fixed high-gain design, leading to excessive gain under normal operating conditions. This causes high-frequency chattering, accelerates LED decay, and forms an irreversible closed loop of excessive gain, aggravated chattering, accelerated light decay, continuous power consumption deterioration, and the need for even higher gain. Conventional adaptive solutions modify the core control gain to adapt to changes in operating conditions, directly undermining the core characteristics of RTM. Chattering suppression methods such as dead-time setting and low-pass filtering introduce additional phase delays, leading to a secondary vicious cycle. It is impossible to simultaneously achieve hard timing constraints, optimal power consumption throughout the entire life cycle, and long-term operational reliability. Summary of the Invention

[0004] To address the aforementioned shortcomings, this application provides a power consumption control system and method for automotive opto-relays based on fixed-time sliding mode, solving the technical problem that existing fixed-time sliding mode control schemes cannot simultaneously retain fixed-time convergence hard constraints and prevent chattering and power consumption closed-loop deterioration.

[0005] In a first aspect, this application provides a power consumption control system for automotive opto-relays based on fixed-time sliding mode, including:

[0006] The status acquisition module is used to acquire the target status and real-time feedback status of the automotive photoelectric relay, and to acquire aging status parameters that characterize the light decay degree of the automotive photoelectric relay.

[0007] The sliding surface calculation module is used to calculate and generate sliding surface state variables based on the target state and the real-time feedback state.

[0008] The sliding mode control module presets a fixed-time sliding mode reaching law, which includes a gain amplitude coefficient and a fractional power parameter. Based on the aging state parameters, the sliding mode control module maintains the gain amplitude coefficient constant and dynamically adjusts the fractional power parameter to obtain the adjusted fixed-time sliding mode reaching law. Based on the sliding surface state variables and the adjusted fixed-time sliding mode reaching law, a continuous control quantity is calculated and generated.

[0009] The drive output module is used to generate discrete drive control signals based on the continuous control quantity and output them to the vehicle photorelay.

[0010] Optionally, acquiring the target state and real-time feedback state of the automotive photorelay includes:

[0011] Within a preset sampling period, the on or off commands of the vehicle photoelectric relay are collected, and the on or off commands are binarized to obtain the target state.

[0012] The on or off feedback signal of the vehicle photorelay is collected synchronously as a real-time feedback status.

[0013] The target state and the real-time feedback state are time-aligned to obtain the target state and the real-time feedback state corresponding to the same sampling time.

[0014] Optionally, the time alignment process includes:

[0015] An instruction buffer based on a first-in-first-out (FIFO) mechanism is established, and the target states that have completed binarization processing within each preset sampling period are pushed into the instruction buffer for temporary storage in sequence.

[0016] Obtain the inherent physical action lag time of the automotive optical relay, and convert the inherent physical action lag time into the corresponding lag sampling cycle number N;

[0017] The real-time feedback state obtained at the current sampling moment is paired and matched with the target state stored in the instruction buffer for N back-tracking beats to obtain the time-domain synchronized target state and real-time feedback state.

[0018] Optionally, obtaining the aging state parameters characterizing the light decay degree of the automotive photorelay includes:

[0019] Collect at least one of the driving current data, conduction response data, and turn-off response data of the automotive photorelay within a preset sampling period;

[0020] The collected data is normalized to generate a data set representing the current device state of the automotive optical relay.

[0021] Each data point in the data set is compared with its corresponding reference calibration data using either a difference or a ratio calculation to obtain each aging offset quantity.

[0022] The aging offset is obtained by weighting the aging offset sub-quantities of each item;

[0023] The aging offset is mapped to obtain the aging state parameters based on the first preset mapping relationship.

[0024] Optionally, the step of calculating and generating the sliding surface state variables based on the target state and the real-time feedback state includes:

[0025] Based on the target state and real-time feedback state at the same sampling time, state error data is calculated and generated.

[0026] The error change rate is calculated and generated based on the state error data of two adjacent sampling times and the preset sampling period.

[0027] The state error data and the error change rate are input into a preset sliding surface expression for combined calculation to obtain the sliding surface state variables.

[0028] Optionally, the step of keeping the gain amplitude coefficient constant based on the aging state parameters and dynamically adjusting the fractional power parameter to obtain the adjusted fixed-time sliding mode reaching law includes:

[0029] The gain amplitude coefficient is preset to a fixed value, and the gain amplitude coefficient remains unchanged under different aging state parameters;

[0030] Establish a second preset mapping relationship between the aging state parameters and the fractional power parameters;

[0031] Based on the second preset mapping relationship, the target fractional power parameter corresponding to the aging state parameter is determined;

[0032] By replacing the fractional power parameter in the current fixed-time sliding mode approach law with the target fractional power parameter, and combining it with the gain amplitude coefficient, the adjusted fixed-time sliding mode approach law is obtained.

[0033] Optionally, the step of calculating and generating continuous control quantities based on the sliding surface state variables and the adjusted fixed-time sliding mode reaching law includes:

[0034] The state variables of the sliding surface are subjected to sign extraction and absolute value processing to obtain the sign direction and sliding surface amplitude, respectively;

[0035] Based on the fractional power parameter in the adjusted fixed-time sliding mode approach law, the amplitude of the sliding mode surface is subjected to fractional power operation to obtain the power approach term;

[0036] The power-law approach term is combined with the sign direction to generate the sliding mode approach term of the sliding surface state variable;

[0037] Based on the gain amplitude coefficient in the adjusted fixed-time sliding mode reaching law, the gain of the sliding mode reaching term is calculated to obtain the continuous control quantity.

[0038] Optionally, generating discrete drive control signals based on the continuous control quantity and outputting them to the automotive photorelay includes:

[0039] The continuous control quantity is subjected to amplitude limiting and normalization to obtain a normalized control value;

[0040] A third preset mapping relationship is established between the normalized control value and the pulse width modulation duty cycle, and the target pulse width modulation duty cycle corresponding to the normalized control value is determined based on the third preset mapping relationship;

[0041] Based on the target pulse width modulation duty cycle, the duration of high level and duration of low level in each preset driving cycle are determined, and a driving control signal in the form of discrete pulses is generated.

[0042] The drive control signal is output to the vehicle photorelay via the drive output interface.

[0043] Optionally, determining the pulse width modulation duty cycle corresponding to the normalized control value based on the third preset mapping relationship includes:

[0044] The range of the normalized control value and the duty cycle adjustment range corresponding to the range of the value are preset;

[0045] Establish a third preset mapping relationship between the normalized control value and the pulse width modulation duty cycle;

[0046] The normalized control value is input into the third preset mapping relationship to obtain the initial pulse width modulation duty cycle;

[0047] Determine whether the initial pulse width modulation duty cycle is within the corresponding duty cycle adjustment range; if the initial pulse width modulation duty cycle is within the corresponding duty cycle adjustment range, determine the initial pulse width modulation duty cycle as the target pulse width modulation duty cycle; if the initial pulse width modulation duty cycle exceeds the corresponding duty cycle adjustment range, perform amplitude limiting processing on the initial pulse width modulation duty cycle to obtain the target pulse width modulation duty cycle.

[0048] Secondly, this application provides a power consumption control method for automotive opto-relays based on fixed-time sliding mode, including:

[0049] The target state and real-time feedback state of the automotive photoelectric relay are obtained, and the aging state parameters characterizing the light decay degree of the automotive photoelectric relay are obtained.

[0050] Based on the target state and the real-time feedback state, the sliding surface state variables are calculated and generated.

[0051] A fixed-time sliding mode approach law is preset, which includes a gain amplitude coefficient and a fractional power parameter; based on the aging state parameters, the gain amplitude coefficient is kept constant, and the fractional power parameter is dynamically adjusted; and based on the sliding surface state variables and the adjusted fixed-time sliding mode approach law, a continuous control quantity is calculated and generated.

[0052] Based on the continuous control quantity, discrete drive control signals are generated and output to the vehicle photorelay.

[0053] Compared with the prior art, the beneficial effects of the present invention are:

[0054] By introducing aging state parameters that characterize the degree of optical decay of devices, the control system can be equipped with the ability to sense the entire life cycle and dynamically adjust according to the actual physical loss of the devices, thereby extending the service life of the photorelay.

[0055] By maintaining a constant gain amplitude to reduce excess gain under normal operating conditions, the tendency to jitter is mitigated, and the stability of the output drive signal is improved. At the same time, by dynamically adjusting the fractional power parameter, the nonlinear curvature of the system convergence is changed, which compensates for the slow response caused by light decay and reduces operating power consumption. Attached Figure Description

[0056] Figure 1 A schematic diagram of a power consumption control system for automotive optical relays based on fixed-time sliding mode, provided in an embodiment of this application;

[0057] Figure 2 A flowchart for obtaining aging state parameters is provided in an embodiment of this application;

[0058] Figure 3 A flowchart illustrating an adjusted fixed-time sliding mode reaching law is provided as an embodiment of this application.

[0059] Figure 4 A flowchart of a power consumption control method for automotive opto-relays based on fixed-time sliding mode provided in an embodiment of this application. Detailed Implementation

[0060] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0061] As a key actuator in safety systems such as battery management systems and high-voltage distribution boxes for new energy vehicles, photorelays are required to meet the following requirements for automotive-grade applications: fixed-time hard constraints on turn-on and turn-off timing, low-power control requirements, and functional safety specifications within a wide temperature range (-40℃ to 125℃) and a full lifespan of 15 years or 200,000 kilometers.

[0062] However, in order to cover the conduction reliability under extreme low temperature and aging end conditions, existing control schemes generally adopt a fixed high-gain sliding mode control design. This design leads to excessive gain under normal operating conditions, which easily causes high-frequency chattering in the system, thereby accelerating the light decay of the light-emitting diode at the physical level. Ultimately, this results in excessive gain, aggravated chattering, accelerated light decay, continuous deterioration of power consumption, and irreversible closed-loop degradation requiring higher gain.

[0063] This application introduces aging state parameters characterizing the degree of optical decay of devices to achieve perception of the aging state of opto-relays throughout their entire lifecycle. While maintaining a constant sliding mode reaching law gain amplitude coefficient and fully preserving the core characteristic of fixed-time convergence in fixed-time sliding mode control, it dynamically adjusts fractional power parameters to change the nonlinear curvature of system convergence. This compensates for the response performance degradation caused by device optical decay, suppresses control chattering under normal operating conditions, and breaks the vicious cycle of excessive gain and optical decay. Simultaneously, it eliminates the need for additional filtering or dead-time components, avoiding performance loss due to phase delay. Ultimately, it simultaneously meets the core requirements of timing constraints, low-power control throughout the entire lifecycle, and long-term operational reliability in automotive-grade scenarios, effectively improving the response speed, power consumption, and operational reliability of automotive opto-relays during long-term service.

[0064] like Figure 1 The diagram shown is a schematic of a power consumption control system for automotive opto-relays based on fixed-time sliding mode provided in an embodiment of this application, including:

[0065] The status acquisition module 10 is used to acquire the target status and real-time feedback status of the automotive photoelectric relay, and to acquire aging status parameters that characterize the light decay degree of the automotive photoelectric relay.

[0066] The sliding surface calculation module 20 is used to calculate and generate sliding surface state variables based on the target state and the real-time feedback state;

[0067] The sliding mode control module 30 presets a fixed-time sliding mode reaching law, which includes a gain amplitude coefficient and a fractional power parameter. Based on the aging state parameters, the sliding mode control module keeps the gain amplitude coefficient constant and dynamically adjusts the fractional power parameter to obtain the adjusted fixed-time sliding mode reaching law. Based on the sliding surface state variables and the adjusted fixed-time sliding mode reaching law, a continuous control quantity is calculated and generated.

[0068] The drive output module 40 is used to generate discrete drive control signals based on the continuous control quantity and output them to the vehicle photorelay.

[0069] To address the issue that automotive relays, under long-term service and extreme temperature conditions, suffer from control errors due to time delays between control commands and actual hardware execution, as well as the irreversible light decay of LEDs, making it difficult to accurately perceive and assess device performance degradation, the state acquisition module 10 in this application embodiment is based on a time alignment mechanism and a multi-dimensional feature data comparison calculation principle to achieve synchronization of state signals and quantitative extraction of aging states.

[0070] In practical implementation, the status acquisition module 10 first acquires in real time the on or off commands of the vehicle photorelay issued by the vehicle safety system through the GPIO pins or CAN / LIN bus interface of the vehicle controller within a preset sampling period. The preset sampling period refers to the time interval at which the main control chip of the control system, such as the MCU, triggers tasks, and is usually set to a fixed value between 1ms and 10ms based on the communication frequency of the vehicle chassis control bus.

[0071] Since such instructions may contain electromagnetic glitches or state machine identifiers, such as hexadecimal codes, during bus transmission, the status acquisition module 10 can binarize them using a preset voltage or numerical threshold. The preset voltage or numerical threshold can be set using dual-threshold hysteresis comparison logic, i.e., a preset high-level judgment threshold V. H For example, 70% of the system voltage Vcc, and the low-level detection threshold V. L For example, 30% of Vcc.

[0072] The specific logic of the state acquisition module 10 performing binarization processing is as follows: the state acquisition module 10 internally maintains a "current instruction status" register. When the historical state of the photorelay is off, i.e., the register is 0, if the real-time acquired instruction voltage rises and is greater than or equal to V... H When the state acquisition module 10 binarizes the signal and determines it as logic "1", it triggers the conduction state and updates the register. During the conduction state, if the command voltage drops significantly due to electromagnetic interference, as long as its voltage value does not fall below V... L That is, in V L With V H During the dead zone hysteresis interval, the state acquisition module 10 will ignore the voltage drop and continue to maintain the state of the previous moment, with the binarized output remaining unchanged as logic "1"; only when the command voltage continues to drop and is less than or equal to V LWhen this happens, the state acquisition module 10 reverses the state and determines it to logic "0", which is the off state, thus determining the target state. The target state refers to the expected logical value issued by the vehicle's power battery management system or power distribution unit, representing the physical connection or disconnection trend that the relay should be in.

[0073] Simultaneously, the status acquisition module 10 synchronously acquires the on or off feedback signal corresponding to the automotive photorelay as real-time feedback status. Real-time feedback status refers to the level signal characterizing the actual contact status of the contacts, obtained through the auxiliary contact feedback circuit or sampling resistor on the secondary side (high-voltage load side) of the photorelay.

[0074] Specifically, at the physical hardware level, the feedback signal is a representation of the actual physical action of the secondary side (high-voltage load side) of the opto-relay. Typically, the status acquisition module 10 uses the high-precision analog-to-digital converter (ADC) channel of the main control chip to sample and monitor the voltage drop across the precision sampling resistor connected in series in the output load circuit in real time, or to acquire the feedback voltage waveform of the auxiliary contact generated by the closure of the internal linkage mechanism of the secondary side (high-voltage load side).

[0075] To convert the analog waveform signal into the logic state required for digital closed-loop control, the state acquisition module 10 uses a data processing algorithm to transform the raw waveform data acquired by the ADC into specific electrical parameters. Specifically, this data processing algorithm first employs a digital filtering algorithm, such as moving average filtering or median filtering, to smooth the discrete ADC sampled code values ​​and filter out high-frequency switching noise in the electromagnetic environment. Then, a linear calibration algorithm is used to accurately map the filtered code value to the actual voltage amplitude based on the main control chip's reference voltage and the ADC resolution. If a sampling resistor mode is used, Ohm's law is further applied to convert the calculated voltage amplitude into the actual load current flowing through the opto-relay.

[0076] Based on this, the state acquisition module 10 sets corresponding physical judgment thresholds. These thresholds define the critical electrical parameter boundaries between the stable closed and fully open states of the relay's physical contacts. For example, when using a sampling resistor mode, these physical judgment thresholds are specifically expressed as preset on-state sustaining current thresholds and off-state leakage current thresholds. The preset on-state sustaining current threshold refers to the minimum load current reference value required to confirm that the internal power switch of the opto-relay, such as a MOSFET or IGBT, has completely left the linear region and entered a stable saturated conduction state. This threshold is typically set based on the hardware specifications of the automotive-grade opto-relay or the vehicle's factory load calibration data, for example, set to 5%~10% of the rated load current, or a fixed empirical value such as 0.5A. Correspondingly, the off-state leakage current threshold refers to the maximum allowable residual current reference value when confirming that the internal power switch of the opto-relay has completely cut off the main load circuit and the entire device has entered a high-impedance off state. This threshold is typically set based on the maximum leakage current specification parameter of the device at its highest nominal operating temperature, for example, set to 10mA to 50mA.

[0077] The status acquisition module 10 compares the actual load current converted by the above algorithm in real time. If the amplitude of the load current rises sharply and exceeds the preset conduction sustaining current threshold, it is determined that the physical connection of the secondary side of the photorelay has been completed, thereby locking the current real-time feedback status to logic "1". Conversely, if the current drops to below the near-zero turn-off leakage current threshold, it is determined that the actual physical contact has been disconnected, and the real-time feedback status is reversed to logic "0".

[0078] Because the photorelay requires a significant physical response time for its internal light-emitting diode to excite photons, the photoelectric receiver to convert photons, and the subsequent MOS / IGBT power switch to turn on or off after receiving the primary control command, the logic transition of the target state precedes the actual transition of the real-time feedback state in terms of timing.

[0079] If the error between the command and the feedback is directly calculated within the same preset sampling period, a false control following error will be generated due to the inherent physical phase difference, which will mislead the subsequent sliding mode control module 30 to release unnecessary high gain, thereby causing the system to oscillate and waste power.

[0080] To eliminate this interference, the state acquisition module 10 performs time alignment processing on the target state and the real-time feedback state to obtain the target state and real-time feedback state corresponding to the same sampling moment. Here, "same sampling moment" does not refer to the same instant in physical time, but rather to a complete action cycle surface belonging to the same issued command and physical response at the algorithmic logic level. The state acquisition module 10 establishes a buffer in memory based on a first-in, first-out (FIFO) mechanism. Within each preset sampling period, the state acquisition module 10 sequentially pushes the currently binarized target state and its corresponding timestamp or sequence number into this buffer for temporary storage. Simultaneously, the system obtains the inherent physical action lag time of the current photorelay through factory calibration or online dynamic calculation and converts it into the number of lag sampling beats N. When outputting the comparison state to subsequent modules, the state acquisition module 10 does not directly extract the target state just generated at the current moment, but instead extracts and matches the currently acquired real-time feedback state with the target state in the buffer that the pointer traces back N beats. Through this space-for-time software delay compensation, the hardware-level transmission lag is logically offset.

[0081] For example, the system's preset sampling period is set to 1ms. When the vehicle bus issues a turn-on command at 10ms, the state acquisition module 10 confirms the target state as logic "1" at 10ms after hysteresis comparison and stores it in the buffer. Due to the physical action of the photorelay having a response delay of approximately 2.5ms, the ADC channel does not detect that the load current reaches the 0.5A turn-on sustaining current threshold until 13ms, at which point the real-time feedback state flips to logic "1". Without time alignment, the system will have a large control error in the 10, 11, and 12ms periods, i.e., the target state is 1, and the real-time feedback state is 0, thus erroneously accumulating sliding mode control quantities. After introducing time alignment processing, the system sets the hysteresis number N to 3, approximately 3ms. Therefore, when calculating at 13ms, the state acquisition module 10 extracts the target state "1" stored in the buffer three cycles back, i.e., at 10ms, and pairs and encapsulates it with the current real-time feedback state "1" at 13ms. In this way, spurious phase differences are eliminated, and the two achieve time-domain synchronization on the same calculation plane.

[0082] like Figure 2 The flowchart shown is for obtaining aging state parameters according to an implementation of this application, including steps S101 to S105, wherein:

[0083] S101, Collect at least one of the driving current data, conduction response data and turn-off response data of the vehicle photorelay within a preset sampling period;

[0084] S102, normalize the collected data to generate a data set representing the current device state of the automotive optical relay;

[0085] S103, perform difference or ratio calculations between each data item in the data group and the corresponding reference calibration data to obtain each aging offset quantity;

[0086] S104, perform a weighted calculation on the aging offset sub-quantities of each item to obtain the aging offset;

[0087] S105, based on the first preset mapping relationship, the aging offset is mapped to obtain the aging state parameters.

[0088] After completing the time-domain synchronization of the target state and the real-time feedback state, in order to solve the problem of irreversible light decay caused by the superposition of long-term thermal stress and electrical stress in the internal light-emitting diode of the automotive photoelectric relay, the state acquisition module 10 acquires the aging state parameters that characterize the light decay degree of the automotive photoelectric relay, and builds a full life cycle state perception and adaptive adjustment mechanism for the entire power consumption control system.

[0089] In practical implementation, the status acquisition module 10 first collects at least one of the following: drive current data, conduction response data, and shutdown response data of the automotive photorelay within a preset sampling period. At the hardware and software level, the drive current data refers to the actual forward excitation current amplitude input to the photorelay's LED, measured in real-time by the main control MCU through the primary side (low-voltage side) current sampling circuit and ADC channel. The conduction response data and shutdown response data are calculated using the precise timestamps recorded in the buffer mentioned above; specifically, the absolute time difference between the moment the target status register changes from logic "0" to logic "1" and the moment the real-time feedback status is finally confirmed as logic "1" by the ADC and threshold is the conduction response data; similarly, the time difference between switching from logic "1" to logic "0" is the shutdown response data.

[0090] As the photon excitation efficiency of LEDs decreases, i.e., light decay, the parasitic capacitance on the light receiving side requires a longer illumination time to accumulate sufficient turn-on charge, which significantly prolongs the conduction response time.

[0091] To eliminate the differences in physical dimensions and numerical distribution range between the current amplitude (mA) and the time parameter (ms or μs), the status acquisition module 10 can use the maximum-minimum extreme value method to normalize the acquired data. Specifically, the system memory presets the physical extreme value range of each parameter. For example, the extreme value range of the conduction response time is set to 0 to 10 ms, and the drive current is set to 0 to 50 mA. The status acquisition module 10 executes the maximum-minimum linear normalization algorithm to subtract the minimum value of the range from the real-time acquired raw value, and then divides it by the difference between the maximum and minimum values, thereby unifying all physical quantities into the standard interval [0,1] and generating a data set representing the current device state of the automotive photorelay.

[0092] Subsequently, the status acquisition module 10 performs calculations on each normalized data item in the data group with the corresponding reference calibration data. The reference calibration data refers to the normalized baseline characteristic values ​​of the same dimension recorded and stored in non-volatile memory such as EEPROM or Flash when the batch of automotive photorelays were in a brand-new, healthy operating condition with zero aging during factory testing.

[0093] The status acquisition module 10 uses difference calculation (subtracting the reference calibration data from the current data) or ratio calculation (dividing the current data by the reference calibration data) to calculate various aging offset sub-quantities. For example, if the normalized value of the current conduction response time is 0.4, while the factory reference value is 0.1, then the calculated conduction aging offset sub-quantity is a difference of 0.3 or a ratio of 4.0. This aging offset sub-quantity intuitively quantifies the absolute or relative degree of deviation of a single physical characteristic from the baseline.

[0094] Furthermore, since the sensitivity of different physical parameters of the photorelay to light decay varies significantly, in order to obtain an accurate comprehensive evaluation result, the state acquisition module 10 performs a weighted calculation on each of the aforementioned aging offset sub-quantities to obtain a comprehensive aging offset. Specifically, the extension of the conduction response time is a direct external manifestation of the light decay of the LED, while the change in the drive current may be affected by voltage fluctuations in the vehicle power supply network, and the extension of the turn-off time is mainly affected by the recombination velocity of the secondary power transistor carriers. Therefore, the system assigns differentiated weight coefficients, for example, the preset weight of the conduction aging offset sub-quantity is 0.6, the weight of the turn-off aging offset sub-quantity is 0.25, and the weight of the drive current aging offset sub-quantity is 0.15. The state acquisition module 10 multiplies each offset sub-quantity by its corresponding weight and sums them to calculate and output a globally fused aging offset.

[0095] Finally, the state acquisition module 10 maps the aging offset to obtain aging state parameters based on the first preset mapping relationship. The first preset mapping relationship is typically represented by a set of piecewise linear interpolation tables or polynomial fitting curve functions embedded within the program. It can be calibrated based on the full lifecycle light decay characteristics of the light-emitting diodes inside the automotive photorelay. By setting an offset threshold representing the decay inflection point, continuous aging offsets are divided into continuous compensation intervals with different mapping slopes.

[0096] Specifically, for example, a first offset threshold representing slight light decay is set to 0.2, and a second offset threshold representing severe light decay is set to 0.5. When the calculated aging offset is between 0 and 0.2, the slope of the mapping curve is low, indicating that the device is in a stable break-in stage at the beginning of its life cycle. The output aging state parameter acts as a dimensionless multiplier for subsequent control, undergoing gentle fine-tuning within an initial range of 1.0 to 1.1. When the aging offset is between 0.2 and 0.5, it indicates that the device has entered a transition stage of moderate light decay. At this time, the mapping relationship increases the compensation slope, so that the output aging state parameter shows a steady linear upward trend with the increase of the aging offset. When the aging offset exceeds 0.5, it indicates that the light-emitting diode has entered a period of accelerated light decay. At this time, the mapping relationship switches to high-slope compensation, such as using an exponential fitting curve, to rapidly and non-linearly amplify the aging state parameter to 1.5 or even above 2.0.

[0097] Through a mapping mechanism with continuous segmented boundaries and a slope that dynamically increases with the degree of aging, the system eliminates the discontinuity of one-dimensional calibration data and transforms the abstract multi-dimensional hardware decay data into continuous mathematical variables that can be directly called by the subsequent sliding mode control module 30 for dynamically reconstructing the sliding mode reaching law parameters.

[0098] As an optional implementation, the step of calculating and generating the sliding surface state variables based on the target state and the real-time feedback state includes:

[0099] Based on the target state and real-time feedback state at the same sampling time, state error data is calculated and generated.

[0100] The error change rate is calculated and generated based on the state error data of two adjacent sampling times and the preset sampling period.

[0101] The state error data and the error change rate are input into a preset sliding surface expression for combined calculation to obtain the sliding surface state variables.

[0102] In practical implementation, the sliding surface calculation module 20 first calculates and generates state error data based on the target state and real-time feedback state at the same sampling time. In the program logic of the digital controller, the sliding surface calculation module 20 extracts the target state after time alignment processing and the corresponding real-time feedback state at the current sampling time. Since the target state and real-time feedback state have been binarized into logic "1" or logic "0" in the front-end state acquisition module 10, the sliding surface calculation module 20 directly performs an algebraic subtraction operation on them, that is, subtracts the real-time feedback state from the target state to obtain discrete state error data.

[0103] When the target command requires conduction but the actual feedback is non-conduction, the state error data is positive (+1), indicating that the system is underdriven and requires positive turn-on energy. When the target command requires de-energization but the actual feedback is not de-energized, the state error data is negative (-1), indicating that the system is overdriven or requires accelerated de-energization. When the actual feedback perfectly follows the target command, the state error data is 0, indicating that the current control has reached a steady state. In this way, the sliding surface calculation module 20 transforms discrete switching logic quantities into state parameters that can be used for continuous space calculations.

[0104] Subsequently, the sliding surface calculation module 20 calculates the error change rate based on the state error data of two adjacent sampling times and a preset sampling period. In the discrete-time domain operation of the microcontroller MCU, since it is not possible to directly perform continuous differentiation on the signal, the sliding surface calculation module 20 can use a first-order backward difference algorithm to approximately extract the derivative features of the error.

[0105] Specifically, the sliding surface calculation module 20 maintains a state register in its internal random access memory to store historical state error data from the previous sampling time. In each calculation cycle, the sliding surface calculation module 20 subtracts the historical state error data from the state error data obtained at the current sampling time to obtain the transient error increment.

[0106] Next, the sliding surface calculation module 20 divides the error increment by the system's preset sampling period, i.e., the system main control timing trigger interval mentioned above, for example, 1ms, to calculate the current error change rate. This error change rate characterizes the dynamic damping trend of the relay's actual operating state approaching or deviating from the target command. When the error change rate is not zero, it reflects that the system's mechanical or electrical contacts are in the transient process of action switching; when the error change rate is zero, it indicates that the system error has not changed, and it may be in a stable maintenance state or a response stagnation state.

[0107] Finally, the sliding surface calculation module 20 combines the state error data and the error change rate with a preset sliding surface expression to obtain the sliding surface state variables. The preset sliding surface expression is a hyperplane function defined in the system's error state space, used to constrain the system's dynamic response trajectory, causing it to converge along a predetermined path.

[0108] Specifically, the preset sliding surface expression is typically configured as a classic first-order linear sliding surface function, where the sliding surface state variable equals the product of the sliding surface weight coefficient and the state error data, plus the error rate of change. The sliding surface weight coefficient is a strictly positive system calibration constant used to adjust the balance between error convergence speed and system anti-interference capability. For example, based on the inherent hardware time constant of the internal light-emitting diode and parasitic capacitance of an automotive-grade photorelay, this empirical value can be set between 50 and 200.

[0109] The sliding surface calculation module 20 substitutes the real-time calculated state error data and error change rate into the first-order linear sliding surface function for multiplication and addition operations. The sliding surface state variable output by the calculation is a continuous real value with positive and negative polarities, representing the algebraic distance and direction of the current operating point of the system from the ideal sliding plane in the state space.

[0110] If the sliding surface state variable is positive, it means that the current state point of the system is above the sliding surface, and the positive drive duty cycle needs to be increased through the subsequent sliding surface approach law; if it is negative, it is below, and the drive energy needs to be weakened; if the value of the variable approaches zero, it means that the control system has successfully pulled the error trajectory to the preset sliding surface. At this time, the system will not be affected by the perturbation of external parameters and will stably slide and converge along the plane to the final equilibrium point where the error and its rate of change are both zero.

[0111] like Figure 3 The flowchart shown illustrates a fixed-time sliding mode reaching law with adjustment provided for implementation of this application, including steps S201-S204, wherein:

[0112] S201, the gain amplitude coefficient is preset to a fixed value, and the gain amplitude coefficient remains unchanged under different aging state parameters;

[0113] S202, establish a second preset mapping relationship between the aging state parameters and the fractional power parameters;

[0114] S203, Based on the second preset mapping relationship, determine the target fractional power parameter corresponding to the aging state parameter;

[0115] S204, replace the fractional power parameter in the current fixed-time sliding mode approach law with the target fractional power parameter, and combine it with the gain amplitude coefficient to obtain the adjusted fixed-time sliding mode approach law.

[0116] The sliding mode control module 30 generates a control quantity that pulls the system state to the sliding surface and maintains stability based on a preset fixed-time sliding mode approach law and combined with the physical aging of the device sensed by the front end.

[0117] In practical implementation, the fixed-time sliding mode reaching law preset by the sliding mode control module 30 is mainly composed of two core control parameters in mathematical structure: the gain amplitude coefficient and the fractional power parameter. Conventional sliding mode control schemes, when dealing with the response delay caused by the aging of photoresistors, usually adopt the method of directly increasing the overall control gain. This leads to high-frequency and drastic control quantity abrupt changes when the system crosses the sliding surface, which is the inherent chattering phenomenon in sliding mode control. This high-frequency chattering not only generates unnecessary electromagnetic interference, but also subjectes the light-emitting diode to frequent current surges, thus falling into a vicious cycle of accelerated light decay, the need for greater gain, more severe chattering, and further deterioration of light decay.

[0118] To prevent vicious cycles, the sliding mode control module 30, based on the aging state parameters, keeps the gain amplitude coefficient constant and dynamically adjusts the fractional power parameters to obtain the adjusted fixed-time sliding mode reaching law. Specifically, the sliding mode control module 30 first presets the gain amplitude coefficient to a fixed value, maintaining this value under different aging state parameters. This fixed value is typically calibrated as a minimum boundary gain constant that can only satisfy the stable switching of the photorelay in a brand-new state, for example, set as an empirical constant between 0.5 and 1.2. Since the gain amplitude coefficient directly determines the switching kinetic energy when the state trajectory reaches the sliding surface, locking it to a small fixed value sets a hard upper limit on the system jitter amplitude at the physical control level, suppressing the high-frequency oscillation of the photorelay output drive signal within a safe low-power range.

[0119] While maintaining a constant gain amplitude coefficient, the sliding mode control module 30 achieves adaptive compensation for device aging by establishing a second preset mapping relationship between the aging state parameters and the fractional power parameters. Since the fractional power parameters determine the nonlinear curvature and upper bound of the convergence time when the system state converges to the sliding surface in the state space, the system has a faster convergence speed far from the sliding surface when the value range of the fractional power parameters is set between 0 and 1.

[0120] The sliding mode control module 30 establishes a second preset mapping relationship in the Flash memory inside the microcontroller. This relationship can be a one-dimensional lookup table or an inverse proportional function. Based on this second preset mapping relationship, the sliding mode control module 30 determines a target fractional power parameter corresponding to the current aging state parameter. Specifically, the second preset mapping relationship can be constructed based on the response hysteresis characteristics caused by the physical aging of the light-emitting diode, characterizing the inverse dynamic adjustment mechanism between the aging state parameter and the target fractional power parameter.

[0121] For example, when the aging state parameter indicates that the device is in brand new condition, the target fractional power parameter output by the lookup table is 0.9, and the system exhibits near-linear conventional convergence characteristics. As the input aging state parameter gradually increases, it indicates that the light decay of the LED is deepening and the response hysteresis is beginning to appear. According to the inverse proportional decreasing logic, the output target fractional power parameter is smoothly or stepwise gradually reduced. When the aging state parameter increases significantly, indicating that the LED has experienced severe light decay and the response hysteresis is prolonged, the target fractional power parameter output by the lookup table is correspondingly reduced to 0.4 or even lower.

[0122] Smaller fractional power parameters enable the system to generate a faster approach speed when the error is large. Thus, without increasing the kinetic energy across the sliding surface or chattering, the response degradation caused by light decay can be compensated by changing the nonlinear convergence characteristics of the approach process.

[0123] Subsequently, the microcontroller's arithmetic unit replaces the fractional power parameter variable in the current fixed-time sliding mode reaching law with the target fractional power parameter. Simultaneously, combining this with the previously locked gain amplitude coefficient, it reconstructs the calculation logic. Specifically, the microcontroller writes the target fractional power parameter obtained from the lookup table into the parameter memory variable corresponding to the reaching law algorithm, overwriting the old fractional power parameter. The memory address containing the gain amplitude coefficient is configured to be read-only or not updated. Through this parameter memory address mapping and variable overwriting process, the microcontroller's control program instantiates a mathematical model including new nonlinear curvature parameters and constant gain, thereby replacing the fractional power parameter in the current fixed-time sliding mode reaching law with the target fractional power parameter. Combined with the gain amplitude coefficient, the adjusted fixed-time sliding mode reaching law is obtained.

[0124] As an optional implementation, the step of calculating and generating continuous control quantities based on the sliding surface state variables and the adjusted fixed-time sliding mode reaching law includes:

[0125] The state variables of the sliding surface are subjected to sign extraction and absolute value processing to obtain the sign direction and sliding surface amplitude, respectively;

[0126] Based on the fractional power parameter in the adjusted fixed-time sliding mode approach law, the amplitude of the sliding mode surface is subjected to fractional power operation to obtain the power approach term;

[0127] The power-law approach term is combined with the sign direction to generate the sliding mode approach term of the sliding surface state variable;

[0128] Based on the gain amplitude coefficient in the adjusted fixed-time sliding mode reaching law, the gain of the sliding mode reaching term is calculated to obtain the continuous control quantity.

[0129] After completing the dynamic reconstruction of the reaching law, the sliding mode control module 30 calculates and generates continuous control quantities based on the sliding surface state variables and the adjusted fixed-time sliding mode reaching law. In the specific algorithm execution of the microcontroller, since directly performing fractional power operations on a potentially negative sliding surface state variable would result in invalid numerical results, the sliding mode control module 30 first performs sign extraction and absolute value processing on the sliding surface state variable.

[0130] Specifically, the sliding mode control module 30 calls the sign function. If the sliding surface state variable is greater than zero, the output sign direction is +1; if it is less than zero, the output sign direction is -1; if it is equal to zero, the output sign direction is 0. At the same time, the absolute value instruction is called to extract the value of the variable, thus obtaining the sliding surface amplitude, which is always a non-negative number.

[0131] Next, the sliding mode control module 30 performs a fractional power operation on the sliding surface amplitude based on the fractional power parameters in the adjusted fixed-time sliding mode reaching law. Specifically, the main control chip can calculate the target fractional power value of the sliding surface amplitude by calling a power function such as the pow function in the standard mathematical library, or by using a fast approximation algorithm based on Taylor expansion or Newton's iteration method to save system clock cycles. The calculation result is the power reaching term in pure numerical form.

[0132] Subsequently, the sliding mode control module 30 performs a multiplication combination operation on the power-law approaching term and the previously extracted sign direction to generate the sliding mode approaching term of the sliding surface state variable. This step restores the algebraic sign of the approaching term, giving the generated sliding mode approaching term a clear polarity characteristic and satisfying the negative definite convergence requirement in the Lyapunov stability condition.

[0133] Finally, the sliding mode control module 30 performs gain calculations, i.e., linear multiplication, on the directional sliding mode reaching term based on the gain amplitude coefficient in the adjusted fixed-time sliding mode reaching law. The algebraic result of the calculation output is the continuous control quantity. This continuous control quantity represents the energy adjustment compensation reference value that needs to be applied to the driving end of the automotive photorelay within the current control cycle to overcome system errors and physical light decay of internal components, thus providing a calculation basis for the final generation of discrete PWM drive electrical signals.

[0134] As an optional implementation, generating discrete drive control signals based on the continuous control quantity and outputting them to the automotive photorelay includes:

[0135] The continuous control quantity is subjected to amplitude limiting and normalization to obtain a normalized control value;

[0136] A third preset mapping relationship is established between the normalized control value and the pulse width modulation duty cycle, and the target pulse width modulation duty cycle corresponding to the normalized control value is determined based on the third preset mapping relationship;

[0137] Based on the target pulse width modulation duty cycle, the duration of high level and duration of low level in each preset driving cycle are determined, and a driving control signal in the form of discrete pulses is generated.

[0138] The drive control signal is output to the vehicle photorelay via the drive output interface.

[0139] After the sliding mode control module 30 calculates the continuous control quantity characterizing the energy regulation compensation reference value, the control system converts the mathematical variables of this continuous space into electrical excitation signals that can be recognized and executed by the hardware circuit. Therefore, the drive output module 40 generates discrete drive control signals based on the continuous control quantity and outputs them to the vehicle photorelay.

[0140] In practical implementation, the drive output module 40 first performs amplitude limiting and normalization processing on the continuous control quantity. Since the sliding mode reaching law equation may output an abnormal control quantity with an extremely large absolute value when the system crosses a pole transient or is subjected to strong external disturbances, the microcontroller pre-sets a safe physical operating boundary for this variable. The microcontroller's limiting logic calls the boundary comparison function to forcibly truncate the continuous control quantity exceeding the safe boundary within the set maximum algebraic compensation range. Then, the limited value is divided by the extreme value span of the boundary to eliminate the original dimensions of the continuous control quantity, resulting in a normalized control value with a range limited to 0 to 1 or -1 to 1.

[0141] In the process of mapping continuous algorithm logic to discrete physical drive, to ensure that the final output drive energy meets automotive-grade response speed requirements without damaging the internal optical components of the relay due to overload, the drive output module 40 pre-sets the value range of the normalized control value and the corresponding duty cycle adjustment range. The duty cycle adjustment range can be configured universally based on the factory hardware specifications of the specific automotive photorelay and the system's thermal design power limit. The upper limit of the duty cycle adjustment range is typically determined based on the maximum continuous forward calibration current that the LED can withstand and its heat dissipation limit, preventing thermal breakdown or rapid acceleration of irreversible light decay. The lower limit of the duty cycle adjustment range is set based on the system's required basic sustaining current or the zero current threshold in a fully off state. For example, to reserve switching dead time and prevent the LED from undergoing thermal breakdown and rapid acceleration of light decay due to prolonged exposure to full load current, the system strictly limits the upper limit of the duty cycle adjustment range to, for example, 85% or 90%, and sets the lower limit to 0 or 5% of the basic bias.

[0142] After determining the boundaries of the two intervals mentioned above, the microcontroller establishes a third preset mapping relationship between the normalized control value and the pulse width modulation duty cycle in the static memory. This mapping relationship can be represented as a set of linear interpolation functions with specific slopes and intercepts, that is, the dimensionless normalized control value is proportionally shifted and scaled to the duty cycle percentage scale of the actual physical execution.

[0143] Specifically, for the normalized control value with positive and negative signs output by the sliding mode algorithm, such as being between -1 and 1, the linear interpolation function achieves reference translation by setting the intercept and polarity conversion and amplitude scaling by setting the slope, in order to adapt to the unidirectional driving characteristic of the light-emitting diode that can only receive non-negative energy.

[0144] First, when the normalized control value is zero, it indicates that the system error has been eliminated and a steady state has been reached. The linear interpolation function maps this value to a base maintenance duty cycle within the duty cycle adjustment range, which is the intercept of the linear interpolation function, used to maintain the current on or off state of the photorelay.

[0145] Secondly, when the normalized control value is positive, it indicates that the system is in an underdriven state or needs accelerated conduction, and the linear interpolation function scales it upwards proportionally. For example, when the normalized control value is at the maximum logic limit, such as +1, it is mapped to the upper limit of the duty cycle, thereby injecting the maximum positive excitation energy within a safe range into the light-emitting diode.

[0146] Finally, when the normalized control value is negative, it indicates that the system is overdriven or requires accelerated discharge shutdown. The linear interpolation function linearly reduces this value downwards from the base maintenance duty cycle. For example, when the normalized control value is at the minimum logic limit, such as -1, it is mapped to the lower limit of the duty cycle.

[0147] The control value in the intermediate state is converted into a corresponding non-negative duty cycle value according to the linear interpolation function relationship. Through the above mapping mechanism based on intercept translation and slope scaling, the system converts continuous algorithm instructions with negative polarity into non-negative pulse width modulation signals that can be directly executed by the underlying timer peripheral.

[0148] Next, the microcontroller inputs the normalized control value into the third preset mapping relationship and obtains the corresponding initial pulse width modulation duty cycle through multiply-accumulate operation instructions.

[0149] To perform secondary hardware security protection and prevent drive signal overflow due to calculation rounding errors or extreme operating conditions, the microcontroller uses the conditional branch judgment instruction of the arithmetic logic unit to determine whether the initial pulse width modulation duty cycle is within the corresponding duty cycle adjustment range.

[0150] If the initial pulse width modulation duty cycle is within the corresponding duty cycle adjustment range, the microcontroller directly determines the initial pulse width modulation duty cycle as the target pulse width modulation duty cycle, proving that the current control requirements are within the hardware's safe execution capability range. If the initial pulse width modulation duty cycle exceeds the corresponding duty cycle adjustment range, the microcontroller performs amplitude limiting processing on the initial pulse width modulation duty cycle, that is, forcibly overwrites the calculated value exceeding the upper limit to the preset upper limit of the duty cycle adjustment range, and forcibly clears the value below the lower limit to zero or overwrites it to the preset lower limit of the duty cycle adjustment range, thereby obtaining a safe and reliable target pulse width modulation duty cycle while ensuring the long service life of the device.

[0151] After determining a safe duty cycle value, the drive output module 40 determines the high-level duration and low-level duration within each preset drive cycle based on the target pulse width modulation duty cycle, generating a discrete pulse-form drive control signal. This is achieved at the microcontroller's hardware peripheral level by configuring a general-purpose timer peripheral. The microcontroller's driver writes the total value of the preset drive cycles into the timer's Auto-reload Register (ARR), and simultaneously writes the product of the target pulse width modulation duty cycle and the ARR into the capture / compare register (CCR) of the corresponding channel of that timer.

[0152] When the timer counter counts up from zero, if the current count value is less than the CCR value, the hardware logic pin outputs a high level; when the count value is greater than the CCR and less than the ARR value, the pin toggles and outputs a low level. Through this hardware register-based counting value segmentation, the system determines the duration of high and low levels within each high-frequency cycle, converting the continuous energy compensation requirement calculated by the aforementioned sliding mode control module 30 into a PWM drive control signal with continuously adjustable duty cycle and discrete pulse form.

[0153] Finally, the drive output module 40 outputs the drive control signal to the automotive photorelay via the drive output interface. Specifically, the microcontroller routes the PWM signal of the internal timer channel to a specific general-purpose input / output (GPIO) pin through on-chip pin multiplexing. The electrical signal of this pin is further connected to the front-end push-pull amplifier circuit or the low-side MOSFET power switch for current gain amplification, and finally injected into the light-emitting diode on the primary side (low-voltage control side) of the automotive photorelay in the form of controlled high-frequency energy pulses.

[0154] Through this seamless connection from high-dimensional sliding surface calculation to pulse output, the system dynamically allocates the driving energy of photon excitation according to the real-time physical loss of the device, so that the turn-on and turn-off actions of the relay converge within a fixed time hard constraint, achieving chatter suppression and power consumption optimization throughout the entire life cycle.

[0155] like Figure 4 The flowchart shown is a process for controlling the power consumption of an automotive opto-relay based on a fixed-time sliding mode, according to an embodiment of this application. It includes steps S301 to S304, wherein:

[0156] S301, acquire the target state and real-time feedback state of the automotive optical relay, and acquire the aging state parameters characterizing the light decay degree of the automotive optical relay;

[0157] S302, Based on the target state and the real-time feedback state, calculate and generate the sliding surface state variables;

[0158] S303, a fixed-time sliding mode approach law is preset, the fixed-time sliding mode approach law includes a gain amplitude coefficient and a fractional power parameter; based on the aging state parameters, the gain amplitude coefficient is kept constant, and the fractional power parameter is dynamically adjusted; and based on the sliding surface state variables and the adjusted fixed-time sliding mode approach law, a continuous control quantity is calculated and generated;

[0159] S304, based on the continuous control quantity, generates discrete drive control signals and outputs them to the vehicle photorelay.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. 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 or all of the technical features therein. Such 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 power consumption control system for automotive opto-relays based on fixed-time sliding mode, characterized in that, include: The status acquisition module is used to acquire the target status and real-time feedback status of the automotive photoelectric relay, and to acquire aging status parameters that characterize the light decay degree of the automotive photoelectric relay. The sliding surface calculation module is used to calculate and generate sliding surface state variables based on the target state and the real-time feedback state. The sliding mode control module presets a fixed-time sliding mode reaching law, which includes a gain amplitude coefficient and a fractional power parameter. Based on the aging state parameters, the sliding mode control module maintains the gain amplitude coefficient constant and dynamically adjusts the fractional power parameter to obtain the adjusted fixed-time sliding mode reaching law. Based on the sliding surface state variables and the adjusted fixed-time sliding mode reaching law, a continuous control quantity is calculated and generated. The drive output module is used to generate discrete drive control signals based on the continuous control quantity and output them to the vehicle photorelay.

2. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 1, characterized in that, The acquisition of the target state and real-time feedback state of the automotive photoelectric relay includes: Within a preset sampling period, the on or off commands of the vehicle photoelectric relay are collected, and the on or off commands are binarized to obtain the target state. The on or off feedback signal of the vehicle photorelay is collected synchronously as a real-time feedback status. The target state and the real-time feedback state are time-aligned to obtain the target state and the real-time feedback state corresponding to the same sampling time.

3. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 2, characterized in that, The time alignment process includes: An instruction buffer based on a first-in-first-out (FIFO) mechanism is established, and the target states that have completed binarization processing within each preset sampling period are pushed into the instruction buffer for temporary storage in sequence. Obtain the inherent physical action lag time of the automotive optical relay, and convert the inherent physical action lag time into the corresponding lag sampling cycle number N; The real-time feedback state obtained at the current sampling moment is paired and matched with the target state stored in the instruction buffer for N back-tracking beats to obtain the time-domain synchronized target state and real-time feedback state.

4. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 1, characterized in that, The acquisition of aging state parameters characterizing the light decay degree of the automotive photorelay includes: Collect at least one of the driving current data, conduction response data, and turn-off response data of the automotive photorelay within a preset sampling period; The collected data is normalized to generate a data set representing the current device state of the automotive optical relay. Each data point in the data set is compared with its corresponding reference calibration data using either a difference or a ratio calculation to obtain each aging offset quantity. The aging offset is obtained by weighting the aging offset sub-quantities of each item; The aging offset is mapped to obtain the aging state parameters based on the first preset mapping relationship.

5. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 3, characterized in that, The step of calculating and generating sliding surface state variables based on the target state and the real-time feedback state includes: Based on the target state and real-time feedback state at the same sampling time, state error data is calculated and generated. The error change rate is calculated and generated based on the state error data of two adjacent sampling times and the preset sampling period. The state error data and the error change rate are input into a preset sliding surface expression for combined calculation to obtain the sliding surface state variables.

6. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 1, characterized in that, The step of maintaining the gain amplitude coefficient constant and dynamically adjusting the fractional power parameter based on the aging state parameters to obtain the adjusted fixed-time sliding mode reaching law includes: The gain amplitude coefficient is preset to a fixed value, and the gain amplitude coefficient remains unchanged under different aging state parameters; Establish a second preset mapping relationship between the aging state parameters and the fractional power parameters; Based on the second preset mapping relationship, the target fractional power parameter corresponding to the aging state parameter is determined; By replacing the fractional power parameter in the current fixed-time sliding mode approach law with the target fractional power parameter, and combining it with the gain amplitude coefficient, the adjusted fixed-time sliding mode approach law is obtained.

7. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 1, characterized in that, The calculation of continuous control quantities based on the sliding surface state variables and the adjusted fixed-time sliding mode reaching law includes: The state variables of the sliding surface are subjected to sign extraction and absolute value processing to obtain the sign direction and sliding surface amplitude, respectively; Based on the fractional power parameter in the adjusted fixed-time sliding mode approach law, the amplitude of the sliding mode surface is subjected to fractional power operation to obtain the power approach term; The power-law approach term is combined with the sign direction to generate the sliding mode approach term of the sliding surface state variable; Based on the gain amplitude coefficient in the adjusted fixed-time sliding mode reaching law, the gain of the sliding mode reaching term is calculated to obtain the continuous control quantity.

8. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 1, characterized in that, The step of generating discrete drive control signals based on the continuous control quantity and outputting them to the automotive photorelay includes: The continuous control quantity is subjected to amplitude limiting and normalization to obtain a normalized control value; A third preset mapping relationship is established between the normalized control value and the pulse width modulation duty cycle, and the target pulse width modulation duty cycle corresponding to the normalized control value is determined based on the third preset mapping relationship. Based on the target pulse width modulation duty cycle, the duration of high level and duration of low level in each preset driving cycle are determined, and a driving control signal in the form of discrete pulses is generated. The drive control signal is output to the vehicle photorelay via the drive output interface.

9. The power consumption control system for automotive opto-relays based on fixed-time sliding mode according to claim 8, characterized in that, The step of determining the pulse width modulation duty cycle corresponding to the normalized control value based on the third preset mapping relationship includes: The range of the normalized control value and the duty cycle adjustment range corresponding to the range of the value are preset; Establish a third preset mapping relationship between the normalized control value and the pulse width modulation duty cycle; The normalized control value is input into the third preset mapping relationship to obtain the initial pulse width modulation duty cycle; Determine whether the initial pulse width modulation duty cycle is within the corresponding duty cycle adjustment range; if the initial pulse width modulation duty cycle is within the corresponding duty cycle adjustment range, determine the initial pulse width modulation duty cycle as the target pulse width modulation duty cycle; if the initial pulse width modulation duty cycle exceeds the corresponding duty cycle adjustment range, perform amplitude limiting processing on the initial pulse width modulation duty cycle to obtain the target pulse width modulation duty cycle.

10. A power consumption control method for automotive opto-relays based on fixed-time sliding mode, implemented based on the power consumption control system for automotive opto-relays based on fixed-time sliding mode as described in any one of claims 1 to 9, characterized in that... include: The target state and real-time feedback state of the automotive photoelectric relay are obtained, and the aging state parameters characterizing the light decay degree of the automotive photoelectric relay are obtained. Based on the target state and the real-time feedback state, the sliding surface state variables are calculated and generated. A fixed-time sliding mode approach law is preset, which includes a gain amplitude coefficient and a fractional power parameter; based on the aging state parameters, the gain amplitude coefficient is kept constant, and the fractional power parameter is dynamically adjusted; and based on the sliding surface state variables and the adjusted fixed-time sliding mode approach law, a continuous control quantity is calculated and generated. Based on the continuous control quantity, discrete drive control signals are generated and output to the vehicle photorelay.

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