Method, system and equipment for EPS-assisted slow ascending and slow descending and storage medium

Abstract

The invention provides a method for EPS power-assisted slow ascending and slow descending, which comprises the following steps: defining an EPS power-assisted state set and a trigger condition set, and constructing an FSM model according to the EPS power-assisted state set and the trigger condition set; the EPS performs power-on initialization, monitors a front power-assisted state, an enable signal, a vehicle speed signal and an ignition voltage signal of the vehicle in real time, and inputs the signals into the FSM model; and a trigger condition is judged through an FSM model according to the front power assisting state in combination with the enable signal, the vehicle speed signal and the ignition voltage signal, a target power assisting state and power assisting current limitation are determined according to the trigger condition, and output of power assisting current is controlled through the power assisting current limitation in the target power assisting state. The method has the beneficial effects that dynamic self-adaptive adjustment of assisting power output under the complex working condition is achieved, assisting power matching is more accurate, assisting power mode switching transition is smoother, and the driving comfort and safety of a driver and passengers are effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle control, and in particular relates to a method for slow rise and slow fall of EPS assistance. Background Art

[0002] Currently, the assistance mode switching control scheme of the automotive electric power steering system EPS (Electric Power Steering) mainly collects real-time data through sensors, and based on a preset assistance characteristic curve or a segmented assistance strategy, realizes the assistance steering output under different working conditions. The switching of its assistance mode is usually triggered based on threshold judgment or fixed logic. After the EPS is ignited and started, it provides assistance after receiving an enable signal (the enable signal of an oil vehicle is that the engine speed reaches a specific threshold, and the enable signal of an electric vehicle is the vehicle CAN bus Ready signal), and stops assisting after receiving a disable signal (the disable signal of an oil vehicle is that the engine speed is less than a specific threshold, and the disable signal of an electric vehicle is that the Ready signal is not detected).

[0003] At present, although there are already transitional processes involved in the switching of the assistance mode, most of them use simple linear interpolation or fixed time delay, and there is insufficient collaborative application of ignition signals, enable signals, vehicle speed signals, and the current assistance state, and complex scenarios such as low-speed creep after startup, hill start, and steering on ice and snow roads cannot be accurately identified, resulting in inaccurate matching of the assistance mode. In summary, the existing EPS assistance mode switching control scheme lacks multi-dimensional state monitoring and refined control logic driven by a state machine, and there are problems such as inaccurate assistance matching and uneven transition in complex scenarios, and cannot meet the driving requirements of comfort and safety. Summary of the Invention

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

[0005] To achieve the above object, the technical solution of the present invention is realized as follows: The first aspect of the present invention provides a method for slow rise and slow fall of EPS assistance, including the following steps: S1. Define the EPS assist status set, including no-assist status, assist ramping-up status, full-assist status, and assist ramping-down status; define the trigger condition set, including C1, C2, C3, C4, C5, C6, where C1 is the condition from no-assist status to assist ramping-up status, C2 is the condition from assist ramping-up status to full-assist status, C3 is the condition from full-assist status to assist ramping-down status, C4 is the condition from assist ramping-down status to no-assist status, C5 is the condition from assist ramping-up status to assist ramping-down status, and C6 is the condition from assist ramping-down status to assist ramping-up status; and construct an FSM model according to the EPS assist status set and the trigger condition set. S2. The EPS performs power-on initialization and continuously monitors the vehicle's front assist status, enable signal, vehicle speed signal, and ignition voltage signal. At the same time, input the front assist status, enable signal, vehicle speed signal, and ignition voltage signal into the FSM model, where the front assist status is used to reflect the current EPS assist status. S3. The FSM model determines the trigger conditions based on the front assist status in combination with the enable signal, vehicle speed signal, and ignition voltage signal, and determines the target assist status and assist current limit according to the trigger conditions. The output of the assist current is controlled by the assist current limit in the target assist status.

[0006] Further, the definitions of each EPS assist status in step S1 are as follows: No-assist status: After the EPS is powered on, no enable signal or vehicle speed signal is received, and no assist is provided. Assist ramping-up status: A transitional state where the assist current increases in a preset gradient. Full-assist status: After the assist ramping-up status is completed, it enters the state where the assist current outputs full assistance. Assist ramping-down status: A transitional state where the assist current decreases in a gradient.

[0007] Further, the enable signal in step S2 is as follows: The enable signal for an oil vehicle is the engine speed, and it is valid when it reaches a specific threshold; the enable signal for an electric vehicle is the vehicle's CAN bus Ready signal. The vehicle speed signal is the real-time vehicle speed obtained through the vehicle's CAN bus, which is used to judge the vehicle's operating conditions. The ignition voltage signal is the vehicle's ignition physical signal, which is used to identify the vehicle's power-on and power-off states.

[0008] Further, the process of determining the trigger conditions and determining the target assist status and assist current limit in step S3 is as follows: When it is detected that the EPS is in the power-on initialization state, the EPS defaults to the non-assisted state, and it continuously monitors the ignition voltage signal, enable signal, and vehicle speed signal. When the enable signal is detected, the EPS enters the assisted slow-rise state and starts the slow-rise timer. When the enable signal is not detected, the EPS remains in the non-assisted state and determines whether the ignition is turned off based on the ignition voltage signal. If so, power-off processing is performed; When it is detected that the previous assisted state changes from the non-assisted state to the assisted slow-rise state, the slow-rise timer is started, and the assisted current linearly increases in a gradient according to the characteristic curve of the preset assisted current changing with time in the assisted slow-rise state. If it is detected in the assisted slow-rise state that the EPS meets the C2 condition and the slow-rise time recorded by the slow-rise timer reaches the preset slow-rise time, it enters the full-assist state. If it is detected in the assisted slow-rise state that the EPS meets the C5 condition, the increase of the assisted current is interrupted, the slow-drop time is calculated according to the current increase ratio, the assisted current limit is obtained, and it transfers to the assisted slow-drop state, and the assisted current output is controlled by the assisted current limit in the assisted slow-drop state; When it is detected that the previous assisted state changes from the assisted slow-rise state to the full-assist state, the full assist is output according to the preset rated assisted current. If it is detected in the full-assist state that the EPS meets the C3 condition, it transfers to the assisted slow-drop state and starts the slow-drop timer; When it is detected that the previous assisted state changes from the full-assist state to the assisted slow-drop state, the slow-drop timer is started, and the assisted current linearly decreases in a gradient according to the characteristic curve of the preset assisted current changing with time in the assisted slow-drop state. If the C4 condition is met and the slow-drop time recorded by the slow-drop timer reaches the preset slow-drop time, it transfers to the non-assisted state. If it is detected in the assisted slow-drop state that the EPS meets the C6 condition, the slow-rise time is calculated according to the current decrease ratio, and it returns to the assisted slow-rise state.

[0009] Furthermore, if the vehicle speed signal is not detected in the full-assist state, assisted degradation is performed.

[0010] Furthermore, in step S3, when the assisted slow-rise state is not completed and the C5 condition is triggered to transfer to the assisted slow-drop state, the slow-drop time corresponding to the assisted slow-drop state is: T2=(1 - RATE1)×t1, where T2 is the slow-drop time, RATE1 is the current increase ratio, and t1 is the preset slow-rise time in the assisted slow-rise state; When the C6 condition is triggered in the assisted slow-drop state to return to the assisted slow-rise state, the slow-rise time corresponding to the assisted slow-rise state is: T1=(1 - RATE2)×t2, where T1 is the slow-rise time, RATE2 is the current decrease ratio, and t2 is the preset slow-drop time in the assisted slow-drop state; In the assisted slow rise state and the assisted slow fall state, the assist current is gradient-controlled, and it is as follows: In the assisted slow rise state, the assist current increases linearly according to I1(t) = I 1max ×t / t1, where I1(t) is the assist current corresponding to the time t in the assisted slow rise state, I 1max is the maximum assist current in the assisted slow rise state, t is the time that the assisted slow rise state has been executed, and when the assisted slow fall state is not completed and transitions to the assisted slow rise state, t = t1 - T1.

[0011] In the assisted slow fall state, the assist current decreases linearly according to I2(τ) = I 2max ×(1 - τ / t2), where I2(τ) is the assist current corresponding to the time τ in the assisted slow fall state, I 2max is the maximum assist current in the assisted slow fall state, τ is the time that the assisted slow fall state has elapsed, and when the assisted slow rise state is not completed and transitions to the assisted slow fall state, τ = t2 - T2.

[0012] The second aspect of the present invention provides a system for EPS assisted slow rise and slow fall, which is used to implement the above method, including: A database module, which is used to define the EPS assist state set, including the non-assist state, the assisted slow rise state, the full assist state, and the assisted slow fall state; define the trigger condition set, including C1, C2, C3, C4, C5, C6; and construct an FSM model according to the EPS assist state set and the trigger condition set; An initialization, monitoring, and input module, which is used to perform initialization when the EPS is powered on, and continuously monitor the vehicle's front assist state, enable signal, vehicle speed signal, and ignition voltage signal, and at the same time input the front assist state, enable signal, vehicle speed signal, and ignition voltage signal into the FSM model; A data processing and output module, which is used to judge the trigger condition through the FSM model according to the front assist state and in combination with the enable signal, vehicle speed signal, and ignition voltage signal, and determine the target assist state and the assist current limit according to the trigger condition, and control the output of the assist current with the assist current limit in the target assist state.

[0013] The third aspect of the present invention provides a device, including: One or more processors; A memory, which is used to store one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the above method for EPS assisted slow rise and slow fall.

[0014] A fourth aspect of the present invention provides a computer-readable storage medium containing computer-executable instructions that, when executed by a computer processor, are used to execute the above method for EPS assisted slow rise and slow fall.

[0015] Compared with the prior art, the present invention has the following advantages: The method for EPS assisted slow rise and slow fall according to the present invention defines the full process states and trigger conditions of EPS mode switching, constructs an FSM model for multi-state collaborative control, and on the premise of obtaining the pre-assist state, performs multi-dimensional collaborative processing in combination with the enable signal, vehicle speed signal, and ignition voltage signal to judge the trigger conditions, and then outputs the assist current limit and the target assist state, and switches to the target assist state according to the constraint conditions of the assist current limit, realizing dynamic adaptive adjustment of the assist output under complex working conditions, making the assist matching more accurate and the assist mode switching smoother, effectively improving the driving comfort and safety of the driver and passengers; fundamentally solving the problem of chaotic control logic of EPS during the power-on and power-off processes from the underlying logic, and significantly improving the handling stability and driving safety performance of EPS under all working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a flowchart of the method for EPS assisted slow rise and slow fall according to Embodiment 1 of the present invention; Figure 2 is a data flow diagram of the FSM model according to Embodiment 1 of the present invention; Figure 3 is a schematic diagram of the EPS assist state conversion relationship according to Embodiment 1 of the present invention; Figure 4 is a flowchart of the FSM model for judging trigger conditions according to Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0018] Hereinafter, embodiments of the present application will be described with reference to the drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present application. However, obviously, one or more embodiments can be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present application.

[0019] The terms used herein are merely for describing specific embodiments and are not intended to limit the present application. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0020] 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.

[0021] In the case of using expressions such as "at least one of A, B, and C, etc.", generally, it should be interpreted according to the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0022] Since the assist current in EPS is used to control the motor to output corresponding torque, and the vehicle mode is switched by controlling the torque change output by the motor, therefore, by studying the output characteristics of the assist current of EPS during mode switching, the present invention provides technical support for controlling vehicle mode switching.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0024] Embodiment 1 A method for EPS-assisted slow rise and slow fall, which is applied to EPS. EPS is respectively communicatively connected to a vehicle controller, a body controller, and a vehicle electronic stability system, and includes the following steps: S1. Define a set of EPS assist states, including a non-assist state, an assist slow rise state, a full assist state, and an assist slow fall state; define a set of trigger conditions, including C1, C2, C3, C4, C5, C6, where C1 is the condition for the non-assist state to the assist slow rise state, C2 is the condition for the assist slow rise state to the full assist state, C3 is the condition for the full assist state to the assist slow fall state, C4 is the condition for the assist slow fall state to the non-assist state, C5 is the condition for the assist slow rise state to the assist slow fall state, and C6 is the condition for the assist slow fall state to the assist slow rise state; and construct an FSM (finite-state machine) model according to the EPS assist state set and the trigger condition set; S2. The EPS performs power-on initialization and continuously monitors the front assist status, enable signal, vehicle speed signal, and ignition voltage signal of the vehicle. At the same time, the front assist status, enable signal, vehicle speed signal, and ignition voltage signal are input into the FSM model, where the front assist status is used to reflect the current EPS assist status; S3. The FSM model determines the trigger condition based on the front assist status in combination with the enable signal, vehicle speed signal, and ignition voltage signal, and determines the target assist status and assist current limit according to the trigger condition. The output of the assist current is controlled by the assist current limit in the target assist status.

[0025] The definitions of each EPS assist status in step S1 are as follows: No-assist status: After the EPS is powered on, no enable signal (i.e., engine speed or Ready signal) or vehicle speed signal is received, and no assist is provided; Assist ramping-up status: A transitional state in which the assist current slowly increases according to a preset gradient to avoid sudden assist intervention; Full-assist status: After the assist ramping-up status is completed, it enters the full-output state of the assist current to meet the normal driving assist requirements; Assist ramping-down status: A transitional state in which the assist current slowly decreases according to a gradient to prevent sudden assist cut-off.

[0026] The enable signal in step S2 is as follows: For gasoline vehicles, the enable signal is the engine speed and is valid when it reaches a specific threshold; for electric vehicles, the enable signal is the vehicle's CAN bus Ready signal; The vehicle speed signal is the real-time vehicle speed obtained through the vehicle's CAN bus and is used to judge the vehicle operating conditions; The ignition voltage signal is the vehicle ignition physical signal collected by the MCU in the EPS and is used to identify the vehicle power-on and power-off states. In this embodiment, the vehicle speed signal and the ignition voltage signal receive vehicle data through the vehicle's CAN bus and obtain the signal status bit and timestamp by parsing.

[0027] The process of determining the trigger condition in step S3 and determining the target assist status and assist current limit according to the trigger condition is as follows: When it is monitored that the EPS is in power-on initialization, the EPS defaults to the no-assist status and continuously monitors the ignition voltage signal, enable signal, and vehicle speed signal. When the enable signal is monitored, the EPS enters the assist ramping-up status and starts the ramping-up timer. When the enable signal is not monitored, the EPS remains in the no-assist status, and it is judged whether the ignition is turned off according to the ignition voltage signal. If so, power-off processing is performed; When it is detected that the front assist state changes from the non-assist state to the assist slow-rise state, that is, when it is detected that the EPS meets the C1 condition, the assist slow-rise state is entered, the slow-rise timer is started, and the assist current linearly increases in a gradient according to the characteristic curve of the preset assist current changing with time in the assist slow-rise state; if it is detected that the EPS meets the C2 condition in the assist slow-rise state and the slow-rise time recorded by the slow-rise timer reaches the preset slow-rise time, the full-assist state is entered; if it is detected that the EPS meets the C5 condition in the assist slow-rise state, the increase of the assist current is interrupted, and the slow-down time is calculated according to the current increase ratio (that is, the ratio of the actual slow-rise time to the preset slow-rise time in the entire assist slow-rise state, which is also the ratio of the current assist current to the preset rated assist current in the full-assist state), the assist current limit is obtained, and the assist slow-down state is entered, that is, the target assist state is the assist slow-down state. In the assist slow-down state, the assist current output is controlled by the assist current limit, and in this process, the assist current limit is the relationship between the assist current in the assist slow-down state and the slow-down time. When it is detected that the front assist state changes from the assist slow-rise state to the full-assist state, that is, when it is detected that the EPS meets the C2 condition, the full-assist state is entered, and the full assist is output according to the preset rated assist current; if it is detected that the EPS meets the C3 condition in the full-assist state, the assist slow-down state is entered, and the slow-down timer is started; if the vehicle speed signal is not detected in the full-assist state, that is, the vehicle speed is lost, the assist is degraded, the assist output is reduced, and the assist output is ensured to be within the safety threshold. For example, the rated assist current in the full-assist state is reduced by 70% for the assist output. When it is detected that the front assist state changes from the full-assist state to the assist slow-down state, that is, when it is detected that the EPS meets the C3 condition, the assist slow-down state is entered, the slow-down timer is started, and the assist current linearly decreases in a gradient according to the characteristic curve of the preset assist current changing with time in the assist slow-down state during the slow-down process; if the C4 condition is met and the slow-down time recorded by the slow-down timer reaches the preset slow-down time, the non-assist state is entered; if it is detected that the EPS meets the C6 condition in the assist slow-down state, the slow-rise time is calculated according to the current decrease ratio (that is, the ratio of the actual slow-down time to the preset slow-down time in the entire assist slow-down state), the assist current limit is obtained, and the assist slow-rise state is returned, that is, the target assist state is the assist slow-rise state. In the assist slow-rise state, the assist current output is controlled by the assist current limit to achieve a smooth switching of the vehicle state, and in this process, the assist current limit is the relationship between the assist current in the assist slow-rise state and the slow-rise time. In this embodiment, the preset speed of the current changing with time in the assist slow-rise state and the assist slow-down state can be the same or different, and it can be set according to actual needs.

[0028] In step S3, when the assisted slow rise state is not completed, condition C5 is triggered to transfer to the assisted slow descent state. The slow descent time corresponding to the assisted slow descent state is related to the remaining increase ratio and is: T2 = (1 - RATE1) × t1, where T2 is the slow descent time (i.e., the time required for the assisted slow descent state when transferring from the assisted slow rise state to the assisted slow descent state), RATE1 is the current increase ratio (i.e., the increase ratio already executed in the assisted slow rise state), 1 - RATE1 is the remaining increase ratio, and t1 is the preset slow rise time in the assisted slow rise state (i.e., the time required to reach the full assistance state from the non - assistance state); When condition C6 is triggered in the assisted slow descent state to return to the assisted slow rise state, the slow rise time corresponding to the assisted slow rise state is related to the completed decrease ratio and is: T1 = (1 - RATE2) × t2, where T1 is the slow rise time (i.e., the time required for the assisted slow rise state when transferring from the assisted slow descent state to the assisted slow rise state), RATE2 is the current decrease ratio (i.e., the decrease ratio already executed in the assisted slow descent state), 1 - RATE2 is the remaining decrease ratio, and t2 is the preset slow descent time in the assisted slow descent state (i.e., the time required to reach the non - assistance state from the full assistance state); In the assisted slow rise state and the assisted slow descent state, the assist current is controlled in a gradient manner and is: In the assisted slow rise state, the assist current increases linearly according to I1(t)=I 1max ×t / t1, where I1(t) is the assist current corresponding to time t in the assisted slow rise state, I 1max is the maximum assist current in the assisted slow rise state, t is the time already executed in the assisted slow rise state, and when transferring from the uncompleted assisted slow descent state to the assisted slow rise state, t = t1 - T1; In the assisted slow descent state, the assist current decreases linearly according to I2(τ)=I 2max ×(1 - τ / t2), where I2(τ) is the assist current corresponding to time τ in the assisted slow descent state, I 2max is the maximum assist current in the assisted slow descent state, τ is the time already executed in the assisted slow descent state, and when transferring from the uncompleted assisted slow rise state to the assisted slow descent state, τ = t2 - T2.

[0029] Under normal circumstances, within a complete operating cycle of the vehicle, the EPS mode switching sequence is as follows: no-assist state - assist ramping-up state - full-assist state - assist ramping-down state - no-assist state. During the process of transitioning from the assist ramping-up state to the full-assist state, the assist current changes as follows: in the assist ramping-up state, the assist current linearly increases in a gradient manner according to the characteristic curve of the preset assist current varying with time in the assist ramping-up state until it reaches the rated assist current and enters the full-assist state for full assistance; during the process of transitioning from the full-assist state through the assist ramping-down state to the no-assist state, the assist current changes as follows: in the assist ramping-down state, the assist current linearly decreases in a gradient manner according to the characteristic curve of the preset assist current varying with time in the assist ramping-down state until no current is output.

[0030] However, if in the assist ramping-up state, before reaching the full-assist state, the C5 condition is triggered, and at this time, it transitions to the assist ramping-down state. In the already executed assist ramping-up state, the assist current linearly increases in a gradient manner according to the characteristic curve of the preset assist current varying with time in the assist ramping-up state. Assuming that the assist current increases to 50% and then transitions to the assist ramping-down state, then the required ramping-down time for executing the assist ramping-down state is T2 = 50% × t1, that is, the required ramping-down time for executing the assist ramping-down state is 50% of the preset ramping-up time in the assist ramping-up state, and the assist current limit to be executed in the target assist state is I2(τ) = I 2max ×(1 - τ / t2), and τ = t2 - T2.

[0031] Similarly, if in the assist ramping-down state, before reaching the no-assist state, the C6 condition is triggered, and at this time, it transitions to the assist ramping-up state. In the already executed assist ramping-down state, the assist current linearly decreases in a gradient manner according to the characteristic curve of the preset assist current varying with time in the assist ramping-down state. Assuming that the assist current decreases to 30% and then transitions to the assist ramping-up state, then the required ramping-up time for executing the assist ramping-up state is T1 = 70% × t2, that is, the required ramping-up time for executing the assist ramping-up state is 70% of the preset ramping-down time in the assist ramping-down state, and the assist current limit to be executed in the target assist state is I1(t) = I 1max ×t / t1, and t = t1 - T1.

[0032] In this embodiment, in step S3, according to the vehicle signal characteristics, the core input signals are divided into three-level states to form a multi-dimensional condition judgment matrix. Table 1 shows the input signal and state comparison table of the FSM model. During this process, although the pre-assist state is one of the core inputs for the FSM model conversion, its role is more reflected in the state continuity judgment and transition logic triggering. It is not used as an independent multi-dimensional judgment matrix condition to be combined with other signals in parallel, but as a necessary prerequisite for the operation of the FSM model, and the effective scope of action of the external signal conditions is limited through state branches.

[0033] Table 1 Comparison Table of Input Signals and States of the FSM Model

[0034] In Table 1, the states of KL15 (ignition signal) are "ON" and "OFF", which respectively represent the cases where the voltage > 10V and the voltage < 9V. It should be noted that in the automotive electronic system, the threshold design of KL15 (ignition signal) (ON > 10V, OFF < 9V) is mainly for the consideration of anti-interference stability and state hysteresis protection, and the 9 - 10V interval belongs to the deliberately designed insensitive area to avoid frequent signal jumps. Therefore, the 9 - 10V interval does not need to be considered here; the states of Engine / VCU (enable signal) are "RUN", "Stop / Crank", and "Invalid / time out". Among them, "RUN" represents the case where the engine speed of the fuel vehicle > 800 rpm or the tram ready = 1, "Stop / Crank" represents the case where the engine speed of the fuel vehicle < 800 rpm or the tram ready = 0, and the meaning of "Invalid / time out" is that the valid bit of the signal = 0 and lasts for 3 s; the states of VehSpd (vehicle speed signal) are "<= 3KPH", "> 3KPH", and "Invalid / time out". Among them, "<= 3KPH" represents the case of low-speed creep, "> 3KPH" represents the case of normal driving, and "Invalid / time out" represents the case where the signal is lost or not updated for 2 s.

[0035] When EPS is powered on and initialized, after EPS is powered on, it defaults to the non-assisted state, initializes the slow-rise timer and the slow-fall timer (t1 = 500 ms, t2 = 300 ms, and of course the preset time can be configured according to actual requirements), and initializes the output of the assist current to 0A. The ignition signal, enable signal, and vehicle speed signal are collected in real time with a period of 100 ms, written into the cache and subjected to validity verification.

[0036] Each time the FSM model is triggered (the trigger period is 100 ms), a signal combination is generated based on the current ignition signal, enable signal, and vehicle speed signal, which serves as the core condition for state transition, and the signal state combination is judged.

[0037] In this embodiment, based on the input signal state combination, the trigger rules for the six trigger conditions are shown in Table 2, Table 2 Trigger Rules for Six Trigger Conditions

[0038] Among them, N represents the non-assisted state, R represents the assisted slow rise state, F represents the full assisted state, and D represents the assisted slow descent state. NR represents the transition from the non-assisted state to the assisted slow rise state, RF represents the transition from the assisted slow rise state to the full assisted state, FD represents the transition from the full assisted state to the assisted slow descent state, DN represents the transition from the assisted slow descent state to the non-assisted state, RD represents the transition from the assisted slow rise state to the assisted slow descent state, and DR represents the transition from the assisted slow descent state to the assisted slow rise state. C1, C2, C3, C4, C5, and C6 can be determined to meet the corresponding switching conditions as long as they meet one of the following following conditions.For example, if the front assist state is the no-assist state and satisfies "Engine / VCU = RUN && KL15 = ON" or "VehSpd > 3KPH && KL15 = ON", it is determined that the C1 condition is satisfied; if the front assist state is the assist ramping-up state and satisfies the condition "Engine / VCU = RUN" or "VehSpd > 3KPH", it is determined that the C2 condition is satisfied; if the front assist state is the full-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 satisfied; if the front assist state is the assist ramping-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 satisfied; if the front assist state is the assist ramping-up 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 C5 condition is satisfied; if the front assist state is the assist ramping-down state and satisfies "Engine / VCU = RUN" or "VehSpd > 3KPH", it is determined that the C6 condition is satisfied.

[0039] As shown in Table 3, all target assist states are listed according to the front assist state, ignition signal, enable signal, and vehicle speed signal.

[0040] Table 3 Relationship Table of Front Assist State, Ignition Signal, Enable Signal, Vehicle Speed Signal, and Target Assist State

[0041] Embodiment 2 A system for EPS assisted slow rise and slow fall, used to implement the above method, includes: A database module, used to define a set of EPS assistance states, including no assistance state, assisted slow rise state, full assistance state, assisted slow fall state; define a set of trigger conditions, including C1, C2, C3, C4, C5, C6; and construct an FSM model according to the set of EPS assistance states and the set of trigger conditions; An initialization, monitoring and input module, used to initialize when the EPS is powered on, and continuously monitor the front assistance state, enable signal, vehicle speed signal and ignition voltage signal of the vehicle, and at the same time input the front assistance state, enable signal, vehicle speed signal and ignition voltage signal into the FSM model; A data processing and output module, used to judge the trigger conditions through the FSM model according to the front assistance state in combination with the enable signal, vehicle speed signal and ignition voltage signal, and determine the target assistance state and assistance current limit according to the trigger conditions, and control the output of the assistance current with the assistance current limit in the target assistance state.

[0042] Embodiment 3 A device, includes: One or more processors; A memory, used to store one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the above method for EPS assisted slow rise and slow fall.

[0043] Embodiment 4 A computer-readable storage medium, containing computer-executable instructions, which are used to execute the above method for EPS assisted slow rise and slow fall when executed by a computer processor.

[0044] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for slow rise and slow fall assisted by EPS, characterized in that, Including the following steps: S1. Define the EPS assistance status set of the vehicle electric power steering system, including no-assistance status, gradual assistance increase status, full-assistance status, and gradual assistance decrease status; define the trigger condition set, including C1, C2, C3, C4, C5, C6, where C1 is the condition for changing from no-assistance status to gradual assistance increase status, C2 is the condition for changing from gradual assistance increase status to full-assistance status, C3 is the condition for changing from full-assistance status to gradual assistance decrease status, C4 is the condition for changing from gradual assistance decrease status to no-assistance status, C5 is the condition for changing from gradual assistance increase status to gradual assistance decrease status, and C6 is the condition for changing from gradual assistance decrease status to gradual assistance increase status; and construct a finite state machine FSM model according to the EPS assistance status set and the trigger condition set; S2. The EPS is powered on and initialized, and the vehicle's front assistance status, enable signal, vehicle speed signal, and ignition voltage signal are monitored in real time. At the same time, the front assistance status, enable signal, vehicle speed signal, and ignition voltage signal are input into the FSM model, where the front assistance status is used to reflect the current EPS assistance status; S3. The FSM model determines the trigger condition based on the front assistance status in combination with the enable signal, vehicle speed signal, and ignition voltage signal, and determines the target assistance status and assistance current limit according to the trigger condition. The output of the assistance current is controlled by the assistance current limit in the target assistance status; The process of determining the trigger condition in step S3 and determining the target assistance status and assistance current limit according to the trigger condition is as follows: When it is monitored that the EPS is in the power-on initialization state, the EPS defaults to the no-assistance status; When it is monitored that the front assistance status changes from the no-assistance status to the gradual assistance increase status, a gradual increase timer is started, and the assistance current linearly increases in a gradient according to the characteristic curve of the preset assistance current changing with time in the gradual assistance increase status; if it is detected in the gradual assistance increase status that the EPS meets the C5 condition, the increase of the assistance current is interrupted, the gradual decrease time is calculated according to the current increase ratio, the assistance current limit is obtained, and the gradual assistance decrease status is entered. The output of the assistance current is controlled by the assistance current limit in the gradual assistance decrease status; When it is monitored that the front assistance status changes from the full-assistance status to the gradual assistance decrease status, a gradual decrease timer is started, and the assistance current linearly decreases in a gradient according to the characteristic curve of the preset assistance current changing with time in the gradual assistance decrease status; if it is monitored in the gradual assistance decrease status that the EPS meets the C6 condition, the gradual increase time is calculated according to the current decrease ratio, and the gradual assistance increase status is returned.

2. A method for EPS-assisted slow lifting and slow lowering according to claim 1, characterized in that, The definitions of each EPS assistance status in step S1 are as follows: No-assistance status: After the EPS is powered on, no enable signal or vehicle speed signal is received, and no assistance is provided; Gradual assistance increase status: A transition state in which the assistance current increases in a preset gradient; Full-assistance status: After the gradual assistance increase status is completed, it enters the state where the assistance current outputs full assistance; Gradual assistance decrease status: A transition state in which the assistance current decreases in a gradient; 3. A method for EPS-assisted slow lifting and slow lowering according to claim 1, characterized in that: In step S2, the enable signal is as follows: for an oil vehicle, the enable signal is the engine speed, and it is valid when it reaches a specific threshold; for an electric vehicle, the enable signal is the vehicle CAN bus Ready signal; The vehicle speed signal is the real-time vehicle speed obtained through the vehicle's CAN bus and is used to judge the vehicle operating conditions; The ignition voltage signal is the vehicle ignition physical signal and is used to identify the vehicle power-on and power-off states.

4. A method for EPS-assisted slow rise and slow fall according to claim 1, characterized in that: In step S3, when the EPS enters the non-assisted state, when the enable signal is detected, the EPS enters the assisted slow-rise state and starts the slow-rise timer. When the enable signal is not detected, the EPS remains in the non-assisted state and judges whether the ignition is turned off according to the ignition voltage signal. If so, power-off processing is performed; When the previous assisted state changes from the non-assisted state to the assisted slow-rise state, if the EPS meets the C2 condition in the assisted slow-rise state and the slow-rise time recorded by the slow-rise timer reaches the preset slow-rise time, it enters the full-assist state; When the previous assisted state changes from the assisted slow-rise state to the full-assist state, full assistance is output according to the preset rated assist current; If the EPS meets the C3 condition is detected in the full-assist state, it switches to the assisted slow-drop state and starts the slow-drop timer; When the previous assisted state changes from the full-assist state to the assisted slow-drop state, if the C4 condition is met and the slow-drop time recorded by the slow-drop timer reaches the preset slow-drop time, it switches to the non-assisted state.

5. A method for EPS-assisted slow rise and slow fall according to claim 4, characterized in that: If the vehicle speed signal is not detected in the full-assist state, assistance degradation is performed.

6. A method for EPS-assisted slow rise and slow fall according to claim 1, characterized in that, In step S3, when the assisted slow-rise state is not completed and the C5 condition is triggered to switch to the assisted slow-drop state, the slow-drop time corresponding to the assisted slow-drop state is: T2 = (1 - RATE1) × t1, where, T2 is the slow-drop time, RATE1 is the current increasing ratio, and t1 is the preset slow-rise time in the assisted slow-rise state; When the C6 condition is triggered in the assisted slow-drop state to return to the assisted slow-rise state, the slow-rise time corresponding to the assisted slow-rise state is: T1 = (1 - RATE2) × t2, where, T1 is the slow-rise time, RATE2 is the current decreasing ratio, and t2 is the preset slow-drop time in the assisted slow-drop state; In the assisted slow-rise state and the assisted slow-drop state, the assist current is controlled in a gradient manner, and it is: During the assisted slow rise state, the assisted current increases linearly according to I1(t) = I 1max ×t / t1, where I1(t) is the assisted current corresponding to the time t during the assisted slow rise state, and I 1max is the maximum assisted current during the assisted slow rise state, t is the time elapsed during the assisted slow rise state, and when the assisted slow descent state is not completed and transitions to the assisted slow rise state, t = t1 - T 1； During the assisted slow descent state, the assist current decreases linearly according to I2(τ)=I 2max ×(1-τ / t2), where I2(τ) is the assist current corresponding to the τ moment during the assisted slow descent state, and I 2max is the maximum assist current during the assisted slow descent state, τ is the time elapsed during the assisted slow descent state, and when the assisted slow ascent state is not completed and transitions to the assisted slow descent state, τ=t2-T2.

7. A system for EPS-assisted slow rise and slow fall, characterized in that, Including: The database module is used to define the EPS assist state set, including the non-assisted state, the assisted slow-rise state, the full-assist state, and the assisted slow-drop state; define the trigger condition set, including C1, C2, C3, C4, C5, C6; And construct the FSM model according to the EPS assist state set and the trigger condition set; The initialization, monitoring and input module is used to perform initialization when the EPS is powered on, and to monitor the previous assist state, enable signal, vehicle speed signal and ignition voltage signal of the vehicle in real time, and at the same time input the previous assist state, enable signal, vehicle speed signal and ignition voltage signal into the FSM model; The data processing and output module is used to judge the trigger condition through the FSM model according to the previous assist state in combination with the enable signal, vehicle speed signal and ignition voltage signal, and determine the target assist state and assist current limit according to the trigger condition, and control the output of the assist current with the assist current limit in the target assist state.

8. A device, characterized in that, Including: One or more processors; The memory is used to store 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 rise and slow fall as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that: It includes computer-executable instructions that, when executed by a computer processor, are used to execute the method for EPS assisted slow rise and slow fall as described in any one of claims 1-6.

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