A method, system, device and storage medium for EPS assisted slow ascent and descent

Abstract

The present invention provides a method for EPS-assisted slow ascent and descent control, comprising the following steps: defining an EPS power-assistance state set and a trigger condition set, and constructing an FSM model based on the EPS power-assistance state set and the trigger condition set; performing power-on initialization on the EPS, monitoring the vehicle's front power-assistance state, enable signal, vehicle speed signal, and ignition voltage signal in real time, and inputting these signals into the FSM model; determining the trigger condition based on the front power-assistance state in combination with the enable signal, vehicle speed signal, and ignition voltage signal through the FSM model, and determining a target power-assistance state and power-assistance current limit based on the trigger condition, and controlling the power-assistance current output in the target power-assistance state using the power-assistance current limit. The present invention has the beneficial effects of achieving dynamic adaptive adjustment of power-assistance output under complex working conditions, making power-assistance matching more accurate and power-assistance mode switching transitions smoother, effectively improving the driving comfort and safety of the driver and passengers.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle control, and in particular relates to a method for EPS-assisted slow ascent and descent. Background Art

[0002] Current automotive electric power steering (EPS) system power-steering mode switching control schemes primarily rely on real-time sensor data collection and, based on preset power-steering characteristic curves or segmented power-steering strategies, achieve power-steering output under different operating conditions. Power-steering mode switching is typically triggered by threshold determination or fixed logic. After ignition, the EPS provides power assistance upon receiving an enable signal (for gasoline vehicles, this is when the engine speed reaches a specific threshold; for electric vehicles, this is when the vehicle's CAN bus Ready signal is detected). Power assistance ceases upon receiving a disable signal (for gasoline vehicles, this is when the engine speed falls below a specific threshold; for electric vehicles, this is when the Ready signal is not detected).

[0003] While existing transition processing methods for power-assist mode switching exist, they often employ simple linear interpolation or fixed-time delays, lacking the coordinated application of ignition signals, enable signals, vehicle speed signals, and the current power-assist status. This makes it impossible to accurately identify complex scenarios such as low-speed creep after startup, hill starts, and steering on icy and snowy roads, leading to inaccurate power-assist mode matching. In summary, existing EPS power-assist mode switching control schemes lack multi-dimensional state monitoring and refined control logic driven by a state machine. This leads to inaccurate power-assist mode matching and jerky transitions in complex scenarios, failing to meet driving requirements for comfort and safety. Summary of the Invention

[0004] In view of this, the present invention aims to overcome the problems of inaccurate power assist matching and uneven transition in complex scenarios in the existing EPS power assist mode switching control method, and proposes a method for EPS power assist slow ascent and descent.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A first aspect of the present invention provides a method for EPS-assisted slow ascent and descent, comprising the following steps:

[0007] S1. Define the EPS power-assist state set, including no power-assist state, power-assist slow-rise state, full power-assist state, and power-assist slow-descent state; define the trigger condition set, including C1, C2, C3, C4, C5, and C6, where C1 is the condition from the no power-assist state to the power-assist slow-rise state, C2 is the condition from the power-assist slow-rise state to the full power-assist state, C3 is the condition from the full power-assist state to the power-assist slow-descent state, C4 is the condition from the power-assist slow-descent state to the no power-assist state, C5 is the condition from the power-assist slow-rise state to the power-assist slow-descent state, and C6 is the condition from the power-assist slow-descent state to the power-assist slow-rise state; and construct an FSM model based on the EPS power-assist state set and the trigger condition set;

[0008] S2. EPS is powered on and initialized. It monitors the vehicle's front power assist status, enable signal, vehicle speed signal, and ignition voltage signal in real time. These signals are then input into the FSM model. The front power assist status reflects the current EPS power assist status.

[0009] S3. The trigger condition is determined by the FSM model based on the pre-assist state and in combination with the enable signal, vehicle speed signal, and ignition voltage signal. The target assist state and assist current limit are determined based on the trigger condition. In the target assist state, the assist current limit is used to control the output of the assist current.

[0010] Furthermore, the definition of each EPS power assist state in step S1 is as follows:

[0011] In the no-assist state, EPS does not receive an enable signal or vehicle speed signal after being powered on, and does not provide assist.

[0012] Assisted slow-rise state, a transitional state in which the assist current increases according to a preset gradient;

[0013] Full power assist state: after the power assist slow rise state is completed, it will enter the power assist current full power assist output state;

[0014] Assisted descent state, a transitional state in which the assist current decreases gradually.

[0015] Furthermore, the enabling signal in step S2 is: the enabling signal of the gasoline vehicle is the engine speed, which is valid when it reaches a specific threshold; the enabling signal of the electric vehicle is the vehicle CAN bus Ready signal;

[0016] The vehicle speed signal is the real-time vehicle speed obtained through the vehicle CAN bus and is used to determine the vehicle's operating conditions;

[0017] The ignition voltage signal is the physical signal of vehicle ignition and is used to identify the vehicle's power-on and power-off status.

[0018] Furthermore, the process of judging the trigger condition in step S3 and determining the target power assist state and power assist current limit according to the trigger condition is as follows:

[0019] When the EPS is detected to be in the power-on initialization state, it enters the non-assist state by default and monitors the ignition voltage signal, enable signal and vehicle speed signal in real time. When the enable signal is detected, the EPS enters the power-assist ramp-up state and starts the ramp-up timer. If the enable signal is not detected, the EPS remains in the non-assist state and determines whether the ignition is off based on the ignition voltage signal. If so, the EPS performs power-off processing.

[0020] When it is detected that the front power assist state changes from the no-assist state to the power assist slow-up state, the slow-up timer is started, and the power assist current is linearly increased according to the characteristic curve of the power assist current changing with time preset in the power assist slow-up state; if it is detected that the EPS meets the C2 condition in the power assist slow-up state, and the slow-up time recorded by the slow-up timer reaches the preset slow-up time, the full power assist state is entered; if it is detected that the EPS meets the C5 condition in the power assist slow-up state, the power assist current increase is interrupted, and the slow-down time is calculated according to the current increase ratio to obtain the power assist current limit, and the vehicle enters the power assist slow-down state, in which the power assist current output is controlled by the power assist current limit;

[0021] When the front power assist state is detected to change from the power assist slow-up state to the full power assist state, full power assist is output according to the preset rated power assist current; if the EPS is detected to meet the C3 condition in the full power assist state, it will change to the power assist slow-down state and start the slow-down timer;

[0022] When it is detected that the front power-assist state changes from the full power-assist state to the power-assist slow-down state, the slow-down timer is started, and the power-assist current is linearly gradient decreased according to the characteristic curve of the power-assist current changing with time preset in the power-assist slow-down state; if the C4 condition is met and the slow-down time recorded by the slow-down timer reaches the preset slow-down time, it is transferred to the no-power-assist state; if it is detected that the EPS meets the C6 condition in the power-assist slow-down state, the slow-up time is calculated according to the current decrease ratio, and the vehicle returns to the power-assist slow-up state.

[0023] Furthermore, if the vehicle speed signal is not detected in the full power-assistance state, the power-assistance is degraded.

[0024] Furthermore, in step S3, when the power-assisted slow-down state is not completed, the C5 condition is triggered to enter the power-assisted slow-down state. The slow-down time corresponding to the power-assisted slow-down state is:

[0025] T2=(1-RATE1)×t1,

[0026] Among them, T2 is the slow-down time, RATE1 is the current increasing ratio, and t1 is the preset slow-up time in the power-assisted slow-up state;

[0027] When the C6 condition is triggered in the power-assisted slow-down state to return to the power-assisted slow-up state, the corresponding slow-up time of the power-assisted slow-up state is:

[0028] T1=(1-RATE2)×t2,

[0029] Among them, T1 is the ramp-up time, RATE2 is the current ramp-down ratio, and t2 is the preset ramp-down time in the assisted ramp-down state;

[0030] In the power-assisted slow-up state and the power-assisted slow-down state, the power-assisted current is controlled in a gradient manner and is:

[0031] In the state of boosting slowly, the boosting current is I1(t)=I 1max ×t / t1 linearly increases, where I1(t) is the power assist current corresponding to time t in the power assist slow rise state, I 1max is the maximum assist current in the assist slow-up state, t is the time the assist slow-up state has been executed, and when the assist slow-down state is not completed and turns to the assist slow-up state, t=t1-T1.

[0032] In the power-assisted descending state, the power-assisted current is I2(τ)= I 2max ×(1-τ / t2) linearly decreases, where I2(τ) is the power assist current corresponding to the moment τ in the power assist descent state, I 2max is the maximum assist current in the assist slow-down state, τ is the time that has passed in the assist slow-down state, and when the assist slow-up state is not completed and enters the assist slow-down state, τ=t2-T2.

[0033] A second aspect of the present invention provides a system for EPS-assisted slow ascent and descent, for implementing the above method, comprising:

[0034] The database module is used to define the EPS power-assistance state set, including no power-assistance state, power-assistance slow-ascending state, full power-assistance state, and power-assistance slow-descent state; define the trigger condition set, including C1, C2, C3, C4, C5, and C6; and construct the FSM model based on the EPS power-assistance state set and trigger condition set;

[0035] The initialization, monitoring, and input module is used to initialize the EPS when it is powered on, and monitor the vehicle's front power assist status, enable signal, vehicle speed signal, and ignition voltage signal in real time. At the same time, the front power assist status, enable signal, vehicle speed signal, and ignition voltage signal are input into the FSM model.

[0036] The data processing and output module is used to judge the trigger conditions based on the front power-assistance state and in combination with the enable signal, vehicle speed signal and ignition voltage signal through the FSM model, and determine the target power-assistance state and power-assistance current limit based on the trigger conditions, and control the output of the power-assistance current with the power-assistance current limit in the target power-assistance state.

[0037] A third aspect of the present invention provides a device comprising:

[0038] one or more processors;

[0039] a memory for storing one or more programs,

[0040] When one or more programs are executed by one or more processors, the one or more processors implement the above-mentioned method for EPS-assisted slow ascent and descent.

[0041] A fourth aspect of the present invention provides a computer-readable storage medium comprising computer-executable instructions, which, when executed by a computer processor, are used to execute the above-mentioned method for EPS-assisted slow ascent and descent.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] The method for EPS assisted slow ascent and descent described in the present invention defines the full-process state and trigger conditions of EPS mode switching, constructs an FSM model of multi-state collaborative control, and on the premise of obtaining the pre-assist state, combines the enable signal, vehicle speed signal and ignition voltage signal for multi-dimensional collaborative processing, judges the trigger conditions, and then outputs the assist current limit and target assist state, switches to the target assist state according to the constraint conditions of the assist current limit, realizes dynamic adaptive adjustment of the assist output under complex working conditions, makes the assist matching more accurate, and the assist mode switching transition smoother, effectively improves the driving comfort and safety of the driver and passengers; fundamentally solves the control logic disorder problem of EPS during power on and off from the underlying logic, and significantly improves the handling stability and driving safety performance of EPS under all working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 This is a flow chart of the method for EPS-assisted slow ascent and descent according to the first embodiment of the present invention;

[0046] Figure 2 The data flow diagram of the FSM model described in the first embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the EPS power assist state transition relationship according to the first embodiment of the present invention;

[0048] Figure 4 This is a flowchart of the FSM model used in Embodiment 1 of the present invention to determine trigger conditions. DETAILED DESCRIPTION

[0049] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0050] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present application. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present application. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present application.

[0051] The terms used herein are only for describing specific embodiments and are not intended to limit this application. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0052] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0053] When using expressions such as "at least one of A, B and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0054] Since the assist current in EPS is used to control the corresponding torque output by the motor, the vehicle mode switching is achieved by controlling the torque change output by the motor. Therefore, the present invention provides technical support for controlling vehicle mode switching by studying the output characteristics of the assist current during EPS mode switching.

[0055] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0056] Example 1

[0057] A method for EPS-assisted slow ascent and descent, applied to the EPS, wherein the EPS is respectively connected to a vehicle controller, a body controller, and a body electronic stability system, comprising the following steps:

[0058] S1. Define the EPS power-assistance state set, including no power-assistance state, power-assistance slow-up state, full power-assistance state, and power-assistance slow-down state; define the trigger condition set, including C1, C2, C3, C4, C5, and C6, where C1 is the condition for transitioning from the no power-assistance state to the power-assistance slow-up state, C2 is the condition for transitioning from the power-assistance slow-up state to the full power-assistance state, C3 is the condition for transitioning from the full power-assistance state to the power-assistance slow-down state, C4 is the condition for transitioning from the power-assistance slow-down state to the no power-assistance state, C5 is the condition for transitioning from the power-assistance slow-up state to the power-assistance slow-down state, and C6 is the condition for transitioning from the power-assistance slow-down state to the power-assistance slow-up state; and construct an FSM (finite-state machine) model based on the EPS power-assistance state set and the trigger condition set.

[0059] S2. EPS is powered on and initialized. It monitors the vehicle's front power assist status, enable signal, vehicle speed signal, and ignition voltage signal in real time. These signals are then input into the FSM model. The front power assist status reflects the current EPS power assist status.

[0060] S3. The trigger condition is determined by the FSM model based on the pre-assist state and in combination with the enable signal, vehicle speed signal, and ignition voltage signal. The target assist state and assist current limit are determined based on the trigger condition. In the target assist state, the assist current limit is used to control the output of the assist current.

[0061] The definition of each EPS power assist state in step S1 is as follows:

[0062] In the no-assist state, the EPS does not receive an enable signal (i.e., engine speed or Ready signal) or a vehicle speed signal after being powered on, and does not provide assist.

[0063] The power assist slow-rise state is a transitional state in which the power assist current increases slowly according to a preset gradient to avoid sudden power assist intervention;

[0064] In the full power-assistance state, after the power-assistance slow-rise state is completed, it enters the power-assistance full-value power-assistance output state to meet the power-assistance needs of normal driving;

[0065] The power assist slow-down state is a transitional state in which the power assist current decreases slowly according to the gradient to prevent the power assist from being suddenly cut off.

[0066] The enable signal in step S2 is: the enable signal of the gasoline vehicle is the engine speed, which is valid when it reaches a specific threshold; the enable signal of the electric vehicle is the vehicle CAN bus Ready signal;

[0067] The vehicle speed signal is the real-time vehicle speed obtained through the vehicle CAN bus and is used to determine the vehicle's operating conditions;

[0068] The ignition voltage signal is a physical signal from the vehicle's ignition, collected by the MCU in the EPS. It's used to identify the vehicle's power-on and power-off states. In this embodiment, the vehicle speed signal and ignition voltage signal are received via the vehicle's CAN bus and analyzed by analyzing the signal status bits and timestamps.

[0069] The process of judging the trigger condition in step S3 and determining the target power assist state and power assist current limit according to the trigger condition is as follows:

[0070] When the EPS is detected to be in the power-on initialization state, it enters the non-assist state by default and monitors the ignition voltage signal, enable signal and vehicle speed signal in real time. When the enable signal is detected, the EPS enters the power-assist ramp-up state and starts the ramp-up timer. If the enable signal is not detected, the EPS remains in the non-assist state and determines whether the ignition is off based on the ignition voltage signal. If so, the EPS performs power-off processing.

[0071] When it is detected that the front power assist state changes from the no-assist state to the power assist slow-up state, that is, when the EPS is detected to meet the C1 condition, the power assist slow-up state is entered, the slow-up timer is started, and the power assist current is linearly increased according to the characteristic curve of the power assist current changing with time preset in the power assist slow-up state; if it is detected that the EPS meets the C2 condition in the power assist slow-up state, and the slow-up time recorded by the slow-up timer reaches the preset slow-up time, the full power assist state is entered; if it is detected that the EPS meets the C5 condition in the power assist slow-up state, the power assist current increase is interrupted, and the slow-down time is calculated according to the current increase ratio (that is, the ratio of the actual slow-up time to the preset slow-up time in the entire power assist slow-up state, which is also the ratio of the current power assist current to the preset rated power assist current in the full power assist state), the power assist current limit is obtained, and the vehicle enters the power assist slow-down state, that is, the target power assist state is the power assist slow-down state, and the power assist current output is controlled by the power assist current limit in the power assist slow-down state, and the power assist current limit in this process is the relationship between the power assist current and the slow-down time when entering the power assist slow-down state;

[0072] When it is detected that the front power-assistance state changes from the power-assistance slow-up state to the full power-assistance state, that is, when it is detected that the EPS meets the C2 condition, it enters the full power-assistance state and outputs full power-assistance according to the preset rated power-assistance current; if it is detected that the EPS meets the C3 condition in the full power-assistance state, it enters the power-assistance slow-down state and starts the slow-down timer; if the vehicle speed signal is not detected in the full power-assistance state, that is, the vehicle speed is lost, the power-assistance is degraded and the power-assistance output is reduced to ensure that the power-assistance output is within the safety threshold, such as outputting power-assistance by 70% of the rated power-assistance current in the full power-assistance state;

[0073] When the front assist state transitions from full assist to assist-down state (i.e., when the EPS meets condition C3), the vehicle enters the assist-down state and starts a downtimer. During the downtime, the assist current decreases linearly according to the assist current-over-time characteristic curve preset in the assist-down state. If condition C4 is met and the downtime recorded by the downtime timer reaches the preset downtime time, the vehicle transitions to the no-assist state. If condition C6 is met during the assist-down state, the ramp-up time is calculated based on the current downtime ratio (i.e., the ratio of the actual downtime time to the preset downtime time in the assist-down state) to obtain the assist current limit. The vehicle then returns to the assist-up state, with the target assist state being the assist-up state. In the assist-up state, the assist current output is controlled using the assist current limit, achieving smooth vehicle state transitions. During this process, the assist current limit reflects the relationship between the assist current and the ramp-up time during the transition to the assist-up state. In this embodiment, the preset current change rates in the assist-up state and the assist-down state can be consistent or inconsistent, depending on actual needs.

[0074] In step S3, when the power-assisted slow-down state is not completed, the C5 condition is triggered to enter the power-assisted slow-down state. The slow-down time corresponding to the power-assisted slow-down state is related to the remaining incremental ratio and is:

[0075] T2=(1-RATE1)×t1,

[0076] Wherein, T2 is the ramp-down time (i.e., the time required to switch from the power-assisted ramp-up state to the power-assisted ramp-down state), RATE1 is the current incremental ratio (i.e., the incremental ratio executed in the power-assisted ramp-up state), 1-RATE1 is the remaining incremental ratio, and t1 is the preset ramp-up time in the power-assisted ramp-up state (i.e., the time required to reach the full power-assisted state from the no-power-assisted state).

[0077] When the C6 condition is triggered in the power-assisted slow-down state to return to the power-assisted slow-up state, the slow-up time corresponding to the power-assisted slow-up state is related to the completed decrement ratio and is:

[0078] T1=(1-RATE2)×t2,

[0079] Wherein, T1 is the ramp-up time (i.e., the time required to switch from the power-assisted slow-down state to the power-assisted slow-up state), RATE2 is the current decrement ratio (i.e., the decrement ratio executed in the power-assisted slow-down state), 1-RATE2 is the remaining decrement ratio, and t2 is the preset decrement time in the power-assisted slow-down state (i.e., the time required to go from the full power-assisted state to the no power-assisted state).

[0080] In the power-assisted slow-up state and the power-assisted slow-down state, the power-assisted current is controlled in a gradient manner and is:

[0081] In the state of boosting slowly, the boosting current is I1(t)=I 1max ×t / t1 linearly increases, where I1(t) is the power assist current corresponding to time t in the power assist slow rise state, I 1max is the maximum power-assisting current in the power-assisting slow-up state, t is the time the power-assisting slow-up state has been executed, and when the power-assisting slow-down state is not completed and the power-assisting slow-up state is entered, t=t1-T1;

[0082] In the power-assisted descending state, the power-assisted current is I2(τ)=I 2max ×(1-τ / t2) linearly decreases, where I2(τ) is the power assist current corresponding to the moment τ in the power assist descent state, I 2max is the maximum assist current in the assist slow-down state, τ is the time the assist slow-down state has been executed, and when the assist slow-up state is not completed and enters the assist slow-down state, τ=t2-T2.

[0083] Under normal circumstances, during a complete vehicle operating cycle, the EPS mode switching sequence is: no power assist - power assist ramp-up - full power assist - power assist ramp-down - no power assist. In the process of reaching the full power assist state from the power assist ramp-up state, the power assist current changes as follows: in the power assist ramp-up state, the power assist current increases linearly according to the power assist current versus time characteristic curve preset in the power assist ramp-up state, until it reaches the rated power assist current, at which point it enters the full power assist state for full power assist. In the process of reaching the no power assist state from the full power assist state through the power assist ramp-down state, the power assist current changes as follows: in the power assist ramp-down state, the power assist current decreases linearly according to the power assist current versus time characteristic curve preset in the power assist ramp-down state, until no current output is achieved.

[0084] If, in the assist slow-up state, the C5 condition is triggered before the full assist state is reached, the assist slow-down state is entered. In the executed assist slow-up state, the assist current is linearly increased according to the assist current versus time characteristic curve preset in the assist slow-up state. Assuming that the assist current increases to 50% and enters the assist slow-down state, the slow-down time required to execute the assist slow-down state is T2=50%×t1, that is, the slow-down time required to execute the assist slow-down state is 50% of the slow-up time preset in the assist slow-up state. The assist current limit to be executed in the target assist state is I2(τ)=I 2max ×(1-τ / t2), and τ=t2-T2.

[0085] Similarly, if in the power-assisted slow-down state, before reaching the no-power-assisted state, the C6 condition is triggered, and the power-assisted slow-up state is entered. In the executed power-assisted slow-down state, the power-assisted current is linearly gradient decreased according to the characteristic curve of the power-assisted current changing with time preset in the power-assisted slow-down state. Assuming that the power-assisted slow-up state is entered when the power-assisted current decreases to 30%, the slow-up time required to execute the power-assisted slow-up state is T1=70%×t2, that is, the slow-up time required to execute the power-assisted slow-up state is 70% of the slow-down time preset in the power-assisted slow-down state. The power-assisted current limit to be executed in the target power-assisted state is I1(t)=I 1max ×t / t1, and t=t1-T1.

[0086] In this embodiment, in step S3, the core input signals are divided into three states based on the vehicle's signal characteristics, forming a multi-dimensional conditional judgment matrix. Table 1 shows the input signal and state comparison table for the FSM model. During this process, the front power assist state, while serving as one of the core inputs for the FSM model transformation, primarily serves to determine state continuity and trigger transition logic. Rather than serving as an independent multi-dimensional judgment matrix condition alongside other signals, it serves as a prerequisite for the FSM model's operation, limiting the effective scope of external signal conditions through state branching.

[0087] Table 1 Input signal and state comparison table of FSM model

[0088]

[0089] In Table 1, the KL15 (ignition signal) states are "ON" and "OFF," indicating voltages > 10V and < 9V, respectively. It should be noted that in automotive electronic systems, the KL15 (ignition signal) threshold design (ON > 10V, OFF < 9V) is primarily for anti-interference stability and state hysteresis protection considerations. The 9-10V range is a deliberately designed insensitive zone to avoid frequent signal transitions. Therefore, the 9-10V range is not considered here. The Engine / VCU (enable signal) states are "RUN," "Stop / Crank," and "Invalid / time out." "RUN" indicates a gasoline vehicle speed > 800 rpm or an electric vehicle ready = 1. "Stop / Crank" indicates a gasoline vehicle speed < 800 rpm or an electric vehicle ready = 0. "Invalid / time out" means the signal valid bit is 0 for 3 seconds. The VehSpd (vehicle speed signal) states are "<=3 kph," ">3 kph," and "Invalid / time out." out", where "<=3KPH" indicates low-speed creeping, ">3KPH" indicates normal driving, and "Invalid / time out" indicates signal loss or no update for 2 seconds.

[0090] During EPS power-up initialization, the EPS enters the non-assist state by default after power is applied. The ramp-up and ramp-down timers are initialized (t1 = 500ms, t2 = 300ms, although the preset times can be configured based on actual needs). The power-assist current output is initialized to 0A. The ignition signal, enable signal, and vehicle speed signal are collected in real time at a 100ms cycle, written to the cache, and validated.

[0091] Each time the FSM model is triggered (the trigger period is 100ms), a signal combination is generated based on the current ignition signal, enable signal, and vehicle speed signal. This is used as the core condition for state transition and the signal state combination judgment is performed.

[0092] In this embodiment, based on the input signal state combination, the triggering rules of the six trigger conditions are shown in Table 2.

[0093] Table 2 Triggering rules for the six trigger conditions

[0094]

[0095] Where N represents the no-assist state, R represents the assisted slow-ascending state, F represents the full-assist state, and D represents the assisted slow-descent state. NR represents the switch from the no-assist state to the assisted slow-ascending state, RF represents the switch from the assisted slow-ascending state to the full-assist state, FD represents the switch from the full-assist state to the assisted slow-descent state, DN represents the switch from the assisted slow-descent state to the no-assist state, RD represents the switch from the assisted slow-ascending state to the assisted slow-descent state, and DR represents the switch from the assisted slow-descent state to the assisted slow-ascending state. C1, C2, C3, C4, C5, and C6 can be considered to have satisfied the corresponding switching condition as long as any of the following conditions is met.For example, if the front power assist state is the no-power assist state and satisfies "Engine / VCU=RUN&&KL15=ON" or "VehSpd>3KPH&&KL15=ON", it is determined that the C1 condition is met; if the front power assist state is the power assist slow-up state and satisfies "Engine / VCU=RUN" or "VehSpd>3KPH", it is determined that the C2 condition is met; if the front power assist state is the full power assist state and satisfies "Engine / VCU=Stop / Crank&&VehSpd<=3KPH" or "Engine / VCU = Invalid / time out&&VehSpd= Invalid / time out" or "Engine / VCU = Stop / Crank&&VehSpd= Invalid / time out" or "VehSpd<=3KPH&&Engine / VCU=Invalid / time out", it is determined that the C3 condition is met; if the front power assist state is the power assist slow-down state and satisfies "Engine / VCU =Stop / Crank&&VehSpd<=3KPH" or "Engine / VCU =Invalid / time out&&VehSpd = Invalid / time out" or "Engine / VCU = Stop / Crank&&VehSpd=Invalid / time out" or "VehSpd<=3KPH&&Engine / VCU = Invalid / time out", it is determined that the C4 condition is met; if the front power-assistance state is the power-assistance slow-up state, and meets the conditions of "Engine / VCU = Stop / Crank&&VehSpd<=3KPH" or "Engine / VCU = Invalid / time out&&VehSpd = Invalid / time out" or "Engine / VCU = Stop / Crank&&VehSpd = Invalid / time out" or "VehSpd<=3KPH&&Engine / VCU=Invalid / time out”, then the C5 condition is determined to be met; if the front power assist state is the power assist descent state, and meets “Engine / VCU = RUN” or “VehSpd>3KPH”, then the C6 condition is determined to be met.

[0096] As shown in Table 3, all target power-assistance states are listed according to the front power-assistance state, ignition signal, enable signal, and vehicle speed signal.

[0097] Table 3 Relationship between front power assist status, ignition signal, enable signal, vehicle speed signal and target power assist status

[0098]

[0099] Example 2

[0100] A system for EPS-assisted slow ascent and descent, for implementing the above method, comprising:

[0101] The database module is used to define the EPS power-assistance state set, including no power-assistance state, power-assistance slow-ascending state, full power-assistance state, and power-assistance slow-descent state; define the trigger condition set, including C1, C2, C3, C4, C5, and C6; and construct the FSM model based on the EPS power-assistance state set and trigger condition set;

[0102] The initialization, monitoring, and input module is used to initialize the EPS when it is powered on, and monitor the vehicle's front power assist status, enable signal, vehicle speed signal, and ignition voltage signal in real time. At the same time, the front power assist status, enable signal, vehicle speed signal, and ignition voltage signal are input into the FSM model.

[0103] The data processing and output module is used to judge the trigger conditions based on the front power-assistance state and in combination with the enable signal, vehicle speed signal and ignition voltage signal through the FSM model, and determine the target power-assistance state and power-assistance current limit based on the trigger conditions, and control the output of the power-assistance current with the power-assistance current limit in the target power-assistance state.

[0104] Example 3

[0105] A device comprising:

[0106] one or more processors;

[0107] a memory for storing one or more programs,

[0108] When one or more programs are executed by one or more processors, the one or more processors implement the above-mentioned method for EPS-assisted slow ascent and descent.

[0109] Example 4

[0110] A computer-readable storage medium contains computer-executable instructions, which are used to execute the above-mentioned method for EPS-assisted slow ascent and descent when executed by a computer processor.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for EPS-assisted slow ascent and descent, characterized in that: The following steps are involved: S1. Define the EPS power state set, including no power, power-assisted slow-up, full power, and power-assisted slow-down. Define the trigger condition set, including C1, C2, C3, C4, C5, and C6, where C1 is the condition from no power to power-assisted slow-up, C2 is the condition from power-assisted slow-up to full power, C3 is the condition from full power to power-assisted slow-down, C4 is the condition from power-assisted slow-down to no power, C5 is the condition from power-assisted slow-up to power-assisted slow-down, and C6 is the condition from power-assisted slow-down to power-assisted slow-up. Construct a finite state machine (FSM) model based on the EPS power state set and trigger condition set. S2. EPS is powered on and initialized. It monitors the vehicle's front power assist status, enable signal, vehicle speed signal, and ignition voltage signal in real time. These signals are then input into the FSM model. The front power assist status reflects the current EPS power assist status. S3. The FSM model determines the trigger condition based on the front power state and the enable signal, vehicle speed signal, and ignition voltage signal, and determines the target power state and power current limit according to the trigger condition. In the target power state, the power current limit controls the power current output; The process of judging the trigger condition in step S3 and determining the target power assist state and power assist current limit according to the trigger condition is as follows: When the EPS is detected to be in the power-on initialization state, the EPS enters the non-assist state by default; When the front power assist state is detected to change from the no-assist state to the power assist slow-up state, the slow-up timer is started, and the power assist current is linearly increased according to the power assist current versus time characteristic curve preset in the power assist slow-up state. If the EPS is detected to meet the C5 condition in the power assist slow-up state, the power assist current increase is interrupted, and the slow-down time is calculated according to the current increase ratio to obtain the power assist current limit. The system then enters the power assist slow-down state, in which the power assist current output is controlled by the power assist current limit. When it is detected that the front power-assist state changes from the full power-assist state to the power-assist slow-down state, the slow-down timer is started, and the power-assist current is linearly gradient decreased according to the characteristic curve of the power-assist current changing with time preset in the power-assist slow-down state; if it is detected that the EPS meets the C6 condition in the power-assist slow-down state, the slow-up time is calculated according to the current decrease ratio and the system returns to the power-assist slow-up state.

2. The method for EPS-assisted slow ascent and descent according to claim 1, characterized in that: The definition of each EPS power assist state in step S1 is as follows: In the no-assist state, EPS does not receive an enable signal or vehicle speed signal after being powered on, and does not provide assist. Assisted slow-rise state, a transitional state in which the assist current increases according to a preset gradient; Full power assist state: after the power assist slow rise state is completed, it will enter the power assist current full power assist output state; Assisted descent state, a transitional state in which the assist current decreases gradually.

3. The method for EPS-assisted slow ascent and descent according to claim 1, characterized in that: In step S2, the enable signal for a gasoline vehicle is the engine speed, which is valid when it reaches a specific threshold; the enable signal for an electric vehicle is the vehicle CAN bus Ready signal; The vehicle speed signal is the real-time vehicle speed obtained through the vehicle CAN bus and is used to determine the vehicle's operating conditions; The ignition voltage signal is the physical signal of vehicle ignition and is used to identify the vehicle's power-on and power-off status.

4. The method for EPS-assisted slow ascent and descent according to claim 1, characterized in that: In step S3, the EPS enters the no-assist state. When the enable signal is detected, the EPS enters the power-assist ramp-up state and starts the ramp-up timer. If the enable signal is not detected, the EPS remains in the no-assist state and determines whether the ignition is off based on the ignition voltage signal. If so, the EPS performs a power-off process. When the front power assist state changes from the no power assist state to the power assist ramp-up state, if the EPS is detected to meet the C2 condition in the power assist ramp-up state and the ramp-up time recorded by the ramp-up timer reaches the preset ramp-up time, the vehicle enters the full power assist state; When the front power assist state changes from the power assist slowly increasing state to the full power assist state, the full power assist is output according to the preset rated power assist current; If the EPS is detected to meet the C3 condition in the full power state, it will switch to the power-assisted descent state and start the descent timer; When the current power-assist state changes from the full power-assist state to the power-assist slow-descent state, if the C4 condition is met and the slow-descent time recorded by the slow-descent timer reaches the preset slow-descent time, the vehicle will be transferred to the no-power-assist state.

5. The method for EPS-assisted slow ascent and descent according to claim 4, characterized in that: If the vehicle speed signal is not detected in the full power-assist state, the power-assistance reduction is performed.

6. The method for EPS-assisted slow ascent and descent according to claim 1, characterized in that: In step S3, when the power-assisted slow-down state is not completed, the C5 condition is triggered to enter the power-assisted slow-down state. The slow-down time corresponding to the power-assisted slow-down state is: T2=(1-RATE1)×t1, Among them, T2 is the slow-down time, RATE1 is the current increasing ratio, and t1 is the preset slow-up time in the power-assisted slow-up state; When the C6 condition is triggered in the power-assisted slow-down state to return to the power-assisted slow-up state, the corresponding slow-up time of the power-assisted slow-up state is: T1=(1-RATE2)×t2, Among them, T1 is the ramp-up time, RATE2 is the current ramp-down ratio, and t2 is the preset ramp-down time in the assisted ramp-down state; In the power-assisted slow-up state and the power-assisted slow-down state, the power-assisted current is controlled in a gradient manner and is: In the state of boosting slowly, the boosting current is I1(t)=I 1max ×t / t1 linearly increases, where I1(t) is the power assist current corresponding to time t in the power assist slow rise state, I 1max is the maximum power-assisting current in the power-assisting slow-up state, t is the time the power-assisting slow-up state has been executed, and when the power-assisting slow-down state is not completed and the power-assisting slow-up state is entered, t=t1-T1; In the power-assisted descending state, the power-assisted current is I2(τ)=I 2max ×(1-τ / t2) linearly decreases, where I2(τ) is the power assist current corresponding to the moment τ in the power assist descent state, I 2max is the maximum assist current in the assist slow-down state, τ is the time that has passed in the assist slow-down state, and when the assist slow-up state is not completed and enters the assist slow-down state, τ=t2-T2.

7. A system for EPS-assisted slow ascent and descent, characterized in that: The method for implementing EPS-assisted slow ascent and descent as claimed in any one of claims 1 to 6 comprises: The database module is used to define the EPS power-assistance state set, including no power-assistance state, power-assistance slow-ascending state, full power-assistance state, and power-assistance slow-descent state; define the trigger condition set, including C1, C2, C3, C4, C5, and C6; and construct the FSM model based on the EPS power-assistance state set and trigger condition set; The initialization, monitoring, and input module is used to initialize the EPS when it is powered on, and monitor the vehicle's front power assist status, enable signal, vehicle speed signal, and ignition voltage signal in real time. At the same time, the front power assist status, enable signal, vehicle speed signal, and ignition voltage signal are input into the FSM model. The data processing and output module is used to judge the trigger conditions based on the front power-assistance state and in combination with the enable signal, vehicle speed signal and ignition voltage signal through the FSM model, and determine the target power-assistance state and power-assistance current limit based on the trigger conditions, and control the output of the power-assistance current with the power-assistance current limit in the target power-assistance state.

8. A device, characterized in that include: one or more processors; a memory for storing one or more programs, When one or more programs are executed by one or more processors, the one or more processors implement the method for EPS-assisted slow ascent and descent as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The invention comprises computer executable instructions, which are used to execute the method for EPS-assisted slow ascent and descent as described in any one of claims 1 to 6 when executed by a computer processor.

Images