ANTI-JUCK CONTROL METHOD FOR AN ELECTRIC VEHICLE

Abstract

Anti-jerk control method for an electric vehicle, wherein the method includes: Determining a vehicle's weight through a control system based on vehicle driving information collected from a vehicle; Determining a required torque command from a driver by the control unit based on the vehicle driving information collected by the vehicle; Determine, by controlling, an anti-jerk torque according to the vehicle weight based on a calculated speed deviation and the determined vehicle weight information after calculating the speed deviation between a model speed and an actual engine speed; and Control, by means of the control, of a drive motor according to a compensated motor torque command by compensating the required torque command with the anti-jerk torque, wherein a weight determination prohibition condition is specified in the control system, wherein the weight determination prohibition condition includes a condition in which a gradient of a roadway on which the vehicle travels is at least a target value, and a condition in which a steering angle is at least a target angle, where determining the vehicle weight, determining the required torque command, determining the anti-jerk torque and controlling the drive motor are only performed if the weight determination prohibition condition is not met.

Description

BACKGROUND(a) Technical field

[0001] The present disclosure relates generally to an anti-jerk control method for an electric vehicle, in particular the anti-jerk control method in which a change in the weight of the electric vehicle driven by a motor is used to perform anti-jerk control more accurately and effectively. (b) Description of the related technique

[0002] As is well known, an electric vehicle (EV) is a vehicle (a motorized vehicle or a motor-driven vehicle) that is powered by a motor as a source (a drive source) of motive force for propelling the vehicle.

[0003] An electric vehicle powertrain comprises: a battery that supplies energy to power the motor; an inverter connected to the battery to power and control the motor; the motor itself as a power source, connected to the battery via the inverter so that the battery can be charged and discharged; and a reduction gear that slows down the motor's rotational force and transmits the slowed rotational force to a drive wheel.

[0004] The inverter works by converting a direct current (DC) supplied during motor operation into an alternating current (AC) to supply the motor with AC via a power cable, and by converting an alternating current generated by the motor's power generation operation during motor regeneration into a direct current so that the battery is supplied with DC to charge the battery.

[0005] Such an electric vehicle is prone to jerking in a low-speed range due to the characteristics of its system, so anti-jerk technology is used to reduce this jerking.

[0006] In an electric vehicle, if a damping element is omitted or becomes smaller, vibrations such as jolts and jerks (temporary and rapid movements) occur during tip-in / tip-out (pressing or releasing the accelerator pedal) together with vibrations of a drive shaft, resulting in poorer ride comfort and handling.

[0007] Since the damping element that is present between the motor, which is a torque source, and the drivetrain is omitted or small, vibrations from the torque source or vibrations from outside are also not reduced in the electric vehicle.

[0008] To solve such a problem, anti-jerk control technology is known, in which vibrations are suppressed by using an anti-jerk torque calculated relative to a model speed to control a motor torque output.

[0009] According to such an anti-jerk control method, when a vehicle starts moving again after stopping, an anti-jerk control system is used to reduce the increase in engine speed and the jerk of the drivetrain that may occur in the initial phase of the vehicle's departure.

[0010] In the case of an electric commercial vehicle such as an electric truck or an electric bus, the change in the total weight of the vehicle due to passengers or loads is greater than that of an electric passenger car.

[0011] In principle, various behavioral characteristics change when a vehicle's overall weight is high. Even on the same road surface, at the same speed, and under the same environmental conditions, changes in a vehicle's overall weight also alters its handling characteristics, which are then transmitted to the driver.

[0012] Anti-jerk control for an electric vehicle was initially applied to an electric passenger car. Since the amount of change in the vehicle's overall weight depending on the number or load of passengers in the electric passenger car is not large, no differentiation based on vehicle weight is necessary during anti-jerk control.

[0013] Since the magnitude of the overall vehicle weight change is large in the electric commercial vehicle, the magnitude of this change must be taken into account. However, conventionally, only one anti-jerk function is known, which is not based on a load condition.

[0014] As the load on a vehicle increases, its characteristics can change, and consequently, its jerking characteristics can also change. Since the existing anti-jerk function operates based on the vehicle's unloaded state, it is difficult to effectively reduce jerking in electric commercial vehicles.

[0015] Accordingly, the electric commercial vehicle requires effective anti-jerk technology that performs an anti-jerk function taking into account changes in its overall weight.

[0016] Furthermore, DE 10 2012 224 294 A1 discloses a method and system for anti-jerk control to reduce the vibration of an electric vehicle. The method includes outputting an actual motor speed; outputting a model motor speed; generating a vibration component based on a deviation between the output model speed and the actual motor speed; high-pass filtering the vibration component to remove an error component; delaying a phase of the filtered vibration component for a preset time to compensate for the phase error occurring during the high-pass filtering; and applying a preset gain to the vibration components, delaying the phase for the preset time to generate an anti-jerk compensation torque based on the application of the preset gain. BRIEF SUMMARY OF THE INVENTION

[0017] Accordingly, the present disclosure proposes an anti-jerk control method for an electric vehicle in which an anti-jerk function can be performed more accurately and effectively by using the weight change of the electric vehicle in real time when the electric vehicle is driven by a motor.

[0018] To solve the above problem, an anti-jerk control method according to claim 1 is provided according to the present invention.

[0019] Accordingly, in an electric commercial vehicle according to the anti-jerk control method of the present invention, it is possible to reduce jerking more effectively under different conditions by implementing an anti-jerk control that is differentiated according to the weight of the vehicle, taking into account changes in the vehicle's weight.

[0020] In particular, according to the present invention, in an electric commercial vehicle such as a bus or a truck with a large change in the number of passengers and the weight of the loaded cargo, the total vehicle weight is accurately determined in real time, and then the determined weight is accurately taken into account to perform the anti-jerk control, thereby maximizing a jerk suppression effect.

[0021] Furthermore, according to the present invention, jerking vibrations of an electric commercial vehicle can be reduced, thereby reducing driver fatigue and improving cargo safety.

[0022] Furthermore, according to the present invention, a non-volatile, computer-readable medium containing program instructions comprises the features of claim 14. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other tasks, features, and other advantages of the present disclosure will become clearer from the following detailed description, together with the accompanying drawings. These show: Fig. 1 a block diagram showing the design of a system that performs an anti-jerk control process according to the present disclosure; and Fig. 2A and Fig. 2B a flowchart showing the anti-jerk control process according to the present disclosure. DETAILED DESCRIPTION OF THE REVELATION

[0024] It is understood that the term "vehicle" or "vehicle-" or other similar terms used herein include motor vehicles in general, such as passenger cars including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft and the like, and hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other vehicles powered by alternative fuels (e.g., fuels derived from resources other than petroleum). A hybrid vehicle referred to herein is a vehicle that has two or more energy sources, such as both gasoline-powered and electric-powered vehicles.

[0025] The terminology used herein serves only to describe certain embodiments and is not intended to limit the disclosure. The singular forms "a," "an," and "the" are used herein to include the plural forms unless the context clearly requires otherwise. Furthermore, it is understood that terms such as "includes" and / or "comprehensive," when used in this specification, indicate the presence of specified features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The term "and / or" used herein includes any and all combinations of one or more of the assigned, listed items.Throughout this specification, unless explicitly stated otherwise, the word "include" and variations such as "includes" or "comprehensive" are to be understood as signifying the inclusion of specified elements, but not the exclusion of any other elements. Additionally, the terms "unit," "-er," "-or," and "module" as described in this specification refer to units for processing at least one function and one operation, and can be implemented using hardware components or software components and combinations thereof.

[0026] Furthermore, the control logic of the present disclosure can be implemented as non-volatile, computer-readable media on a computer-readable medium containing executable program instructions that are executed by a processor, controller, or the like. Examples of computer-readable media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), compact disc ROMs (CD-ROMs), magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable medium can also be distributed across networked computer systems, allowing computer-readable media to be stored and executed in a distributed manner, for example, by means of a telematics server or a CAN (controller area network).

[0027] An embodiment of the present disclosure is described in detail below with reference to the accompanying drawings, so that a person skilled in the art to which the present disclosure belongs can easily implement the embodiment. However, the present disclosure is not limited to the embodiment described herein, but can be implemented in other forms.

[0028] As described above, in an electric commercial vehicle such as a bus or truck, the number of passengers and the weight of the loaded cargo can change significantly during the vehicle's journey, so anti-jerk control technology is needed that takes into account the overall weight change of the vehicle.

[0029] For this purpose, in electric commercial vehicles where the overall weight change of a vehicle is large, it is necessary to accurately detect the current vehicle weight in real time and to perform anti-jerk control according to the current vehicle weight.

[0030] The present disclosure is characterized in that, after the total weight of a vehicle is accurately determined in real time during the journey, the determined total vehicle weight is taken into account in order to execute the anti-jerk control.

[0031] Accordingly, jerking can be effectively reduced under various conditions, and a jerk suppression effect can be maximized if the anti-jerk control is implemented according to the total weight of a vehicle.

[0032] In the following description, vehicle weight refers to the total weight of a vehicle, in which the weight of passengers or the weight of cargo is added to the weight of the vehicle when the passengers are present or the cargo is loaded into it.

[0033] Fig. Figure 1 is a block diagram showing the design of a system that performs an anti-jerk control process according to the present disclosure, and shows, in addition to an anti-jerk control system, a drive motor 41 that drives a vehicle, a reduction gear 42 that reduces the torque of the motor 41 and transmits the reduced torque, and a drive wheel 43 that is rotated by the torque of the motor transmitted by the reduction gear 42.

[0034] The anti-jerk control process according to the present disclosure can be executed by the combined control of a plurality of controllers provided in a vehicle. The anti-jerk control process can be executed by an integrated controller. In the following description, the anti-jerk control process is executed by the combined control of a first controller 20 and a second controller 30.

[0035] In the following description, a controlled object is divided into the first control 20 and the second control 30. However, it is understood that the plurality of controls or the integrated control element is usually referred to as the control, and the anti-jerk control process according to the present disclosure is performed by the control.

[0036] Fig. 2A and Fig.Figure 2B is a flowchart illustrating the anti-jerk control process as disclosed herein. While the design of the system in Fig. As described in section 1, the anti-jerk control process is described with reference to Fig. 2A and Fig. 2B described.

[0037] Referring to Fig. 1 The anti-jerk control system according to the present disclosure comprises the first control 20, which determines the vehicle weight from vehicle driving information collected from a vehicle, and the second control 30, which performs the anti-jerk control according to the vehicle weight using the vehicle weight information determined by the first control 20.

[0038] In the present disclosure, the first control 20 can be a vehicle control unit (VCU) that determines and generates a required torque command from the vehicle driving information and outputs the required torque command.

[0039] In the present disclosure, the first controller 20 calculates the required torque command from the driver in real time based on driving input information from the driver and vehicle state information from the vehicle driving information, which is determined during the journey of the vehicle, and determines the vehicle weight in real time in order to transmit the calculated required torque command and the determined vehicle weight to the second controller 30.

[0040] Furthermore, in the present disclosure, the second control 30 can be a motor control unit (MCU) that operates an inverter with a motor torque command and controls the motor 41.

[0041] In a typical electric vehicle, the motor control unit (MCU) performs the anti-jerk control. After the MCU determines the anti-jerk torque, the required torque command received from the vehicle control unit is compensated for by the anti-jerk torque, and the motor is controlled with the compensated motor torque command.

[0042] However, in the present disclosure, the second control unit 30 (for example, an engine control unit) is provided to receive the determined vehicle weight information from the first control unit 20 (for example, a vehicle control unit) and to execute the anti-jerk control according to the vehicle weight.

[0043] In the present disclosure, various weight determination methods can be used to determine the vehicle weight. Many vehicle weight determination methods are known that utilize the vehicle driving information collected from a vehicle, and any of the known weight determination methods can be applied.

[0044] According to the embodiment of the present disclosure, the vehicle driving information required for determining the vehicle weight in the first control 20 can include vehicle speed, acceleration and engine torque.

[0045] The vehicle speed and acceleration, the vehicle driving information required for determining the vehicle weight, are detected by a vehicle driving information detector 10. The vehicle driving information detector 10 can include sensors that detect the vehicle speed and acceleration.

[0046] A sensor of the vehicle information detector 10, which detects the vehicle speed, can be a wheel speed sensor 11 mounted on a vehicle wheel. It is known that wheel speed and vehicle speed information can be obtained from the signal of the wheel speed sensor 11.

[0047] For example, the signals from wheel speed sensors 11, which are mounted on a large number of wheels in a vehicle, can be used. By averaging the rotational speeds (wheel speeds) of the wheels obtained from the signals of the wheel speed sensor 11, an average speed or rotational speed can be obtained, and real-time vehicle speed information can be derived from this average speed or rotational speed of the wheels.

[0048] Furthermore, a sensor of the vehicle information detector 10, which detects acceleration, can be a vertical acceleration sensor 12 mounted on a vehicle. In this case, the acceleration is real-time vertical acceleration information of the vehicle, detected by the vertical acceleration sensor 12.

[0049] The vertical acceleration detected by the vertical acceleration sensor 12 is used to obtain the gradient information of a roadway on which a vehicle is currently traveling, and the information of the roadway gradient (a roadway inclination angle θ) is used to determine the weight of the vehicle.

[0050] Accordingly, the road gradient θ can be obtained using the vertical acceleration information detected by the vertical acceleration sensor 12, and in this case, can also be obtained by further using the vehicle acceleration. The vehicle acceleration can be obtained by deriving the vehicle speed.

[0051] For example, the road gradient θ can be calculated using the equation "θ = 1 / g×(vertical acceleration - vehicle acceleration)". Here, g represents the acceleration due to gravity.

[0052] Such a method for calculating the road gradient θ is merely an example and the present disclosure is not limited to it, and any method can be applied in which real-time gradient information of a roadway on which a vehicle is currently traveling can be obtained.

[0053] For example, road gradient information at a current vehicle position can be obtained from a GPS signal received by a vehicle's GPS receiver and 3D map information, and the vehicle's weight can be determined using the road gradient information obtained in this way.

[0054] Furthermore, the engine torque from the vehicle weight determination driving information can be an engine torque command used to control a drive motor.

[0055] The vehicle driving information required to determine the engine torque command includes driver input information and vehicle state information. Driver input information may include an accelerator pedal input value (APS value) and a brake pedal input value (BPS value), and vehicle state information may include the vehicle speed.

[0056] The vehicle driving information required to determine the engine torque command can be detected by the vehicle's driving information detector 10. For this purpose, the driving information detector 10 can further comprise an accelerator pedal detector 14, which detects the accelerator pedal input information according to the state of the accelerator pedal manipulation by a driver, and a brake pedal detector 15, which detects the brake pedal input information according to the state of the brake pedal manipulation by the driver.

[0057] In this case, the accelerator pedal detector 14 can be a known accelerator position sensor (APS) that is mounted on the accelerator pedal and outputs an electrical signal according to the state of the accelerator pedal manipulation by the driver.

[0058] Furthermore, the brake pedal detector 15 can be a known brake pedal sensor (BPS) that is mounted on a brake pedal and outputs an electrical signal according to the state of brake pedal manipulation by the driver.

[0059] Finally, the first controller 20 can determine the current weight information of a vehicle based on real-time driving information such as vehicle speed, road gradient, and engine torque command. Equation 1 below shows an example of a formula used to determine the vehicle weight. m=∫t0tl[ηRDrtire(τMotBeAj)−(fo+f1υ+f2υ2)]dt[Δυ+∫t0tlgsinθdt]

[0060] Here, m denotes the vehicle weight, η RD denotes the efficiency of the reduction gear, and r tire denotes a dynamic radius of a tire.

[0061] Furthermore, in equation 1 τMotBeAj the motor torque, which can be the motor torque command used to control the drive motor 41.

[0062] Furthermore, in equation 1, fo, f1, and f2 denote drive loads, v denotes the vehicle speed, g denotes the acceleration due to gravity, and θ denotes the road gradient.

[0063] Although the method and equation for determining the vehicle weight are described, the present disclosure is not limited to the weight determination method and the aforementioned equation. Any known method for accurately determining the vehicle weight can be applied to the present disclosure.

[0064] For example, the first controller 20 receives the acceleration value and can calculate the vehicle weight using a vehicle driving force F and the acceleration value a. In "F = m × a", it is possible to calculate m using "F / a" according to the vehicle weight.

[0065] Furthermore, as another example of vehicle weight estimation, a patent application entitled “Vehicle Weight Estimation Method by Acceleration Sensor” (Korean patent application no. 10-2019-0158424, filed on October 8, 2019) was filed by the applicant of the subject matter of the application, and this vehicle weight estimation method can be applied to the present disclosure.

[0066] Furthermore, in the present disclosure, a weight determination prohibition condition may be specified in the first control 20, and the weight determination prohibition condition may include a condition in which the road gradient is at least a target value and a condition in which a steering angle is at least a target angle.

[0067] This means that if the road gradient is at least the target value and the steering angle is at least the target angle, it is determined that the weight determination prohibition condition is met, so the first control unit 20 does not perform the vehicle weight determination. Accordingly, the anti-jerk control, in which a determined vehicle weight is taken into account, is not executed.

[0068] In this case, the existing engine control or anti-jerk control can be executed without using the determined vehicle weight.

[0069] Alternatively, if the weight determination prohibition condition is not met, the vehicle weight determination is performed, and then the anti-jerk control is performed, taking the determined vehicle weight into account.

[0070] As described above, the driving information detector 10 may further include a steering angle sensor 16 which detects the steering angle according to the state of steering wheel manipulation by the driver in order to determine whether the weight determination prohibition condition is met.

[0071] As described above, the first controller 20 calculates the required torque command from the driver in real time based on the driver's driving input information and the vehicle state information during driving. The driver's driving input information can include the accelerator pedal input value (APS value) and the brake pedal input value (BPS value), and the vehicle state information can include the vehicle speed.

[0072] In the first control 20, the required torque command can be determined based on the APS value and the BPS value of the driver, which reflect the driver's requirements, and current vehicle speed information.

[0073] As provided herein, the process or procedure for calculating the required torque command does not differ from the process or procedure by which the vehicle control unit calculates the required torque command using the vehicle's driving information collected in real time in a normal electric vehicle and is a known technology, therefore a detailed description of it is omitted.

[0074] Finally, as described above, the current vehicle weight, determined by the first controller 20, and the required torque command calculated from this, are transmitted in real time to the second controller 30.

[0075] Referring to Fig. 2A and Fig.2B shows that a process in which the driving information collected from a vehicle is input to the first controller 20 and the third controller 30 is executed in S11, a process in which the first controller 20 determines whether the weight determination prohibition condition is met is executed in S12, a process in which, if the weight determination prohibition condition is not met, the vehicle weight determination is carried out in the first controller 20 in S13, and a process in which the determined vehicle weight and the required torque command are output by the first controller 20 is executed in S14.

[0076] Before the anti-jerk control is executed, the second control unit 30 in S12' determines, based on the vehicle driving information, whether the anti-jerk control can currently be executed, i.e., whether an anti-jerk enable state is met. The vehicle driving information can include gear information (P, R, N, and D gear information) and operating information of the traction control system (TCS).

[0077] Gear information can be entered by a shift control unit (not shown) or a shift lever detector (not shown).

[0078] Although the gearshift detector in Fig. Not shown in section 1, the vehicle information detector comprises 10 of Fig. 1 furthermore the gearshift detector, if it is provided that the second control 30 receives the gear information (gearshift position information) directly from the gearshift detector.

[0079] The gearshift detector detects the gearshift position information (P, R, N and D gear information) according to the state of gearshift manipulation by the driver.

[0080] In the present disclosure, the second control 30 determines that the anti-jerk release state is not satisfied if a gear is a P stage, which is a park stage, or an N stage, which is neutral, and does not execute the anti-jerk control.

[0081] Furthermore, during ASR operation it is determined that the anti-jerk release state is not met, and the anti-jerk control is not executed.

[0082] Alternatively, if a gear is not the P gear or the N gear, that is, if ASR is not in operation while an actual gear is a D stage, which is a driving stage, or an R stage, which is a reverse gear, it is determined that the anti-jerk release condition is met.

[0083] If, as described above, it is determined that the anti-jerk release state is met, the second control 30 in S13' determines an anti-jerk mode using the current driving information of a vehicle.

[0084] In the present disclosure, the anti-jerk mode can be classified according to the driving conditions for effective anti-jerk control. The anti-jerk mode is classified to differentiate the anti-jerk torque according to the driving condition of a vehicle and can be a mode corresponding to braking, acceleration, a constant speed, or an anti-jerk locking condition.

[0085] For example, the anti-jerk mode in the present disclosure can comprise at least two modes: an anti-jerk off mode (a mode “AJ 0”), a braking mode (a mode “AJ 1”), a tip-in mode (a mode “AJ 2”) and a tip-out mode (a mode “AJ 3”).

[0086] The anti-jerk off mode is a mode in which the anti-jerk control is deactivated, and the brake mode is an anti-jerk mode at a time when braking is performed by the driver pressing a brake pedal.

[0087] A case in which the anti-jerk control is disabled can be defined as a case in which a predetermined anti-jerk locking condition is met, or as a case in which an actual gear is the P stage, which is a park stage, or the N stage, which is neutral, even in a case that does not meet the anti-jerk locking condition.

[0088] Furthermore, the Tip-In mode is an anti-jerk mode (torque increase) at the point when the driver presses the accelerator pedal, and the Tip-Out mode is an anti-jerk mode (torque reduction) at the point when the driver takes their foot off the accelerator pedal.

[0089] In the preceding description, the anti-jerk mode was described as comprising a total of four modes, but this is merely an example, and the present disclosure is not limited to it. The anti-jerk mode can be modified in various ways with regard to its nature or number, the definitions of each of its modes, and a driving condition intended for each mode.

[0090] For example, in the present disclosure, the anti-jerk mode, instead of the anti-jerk-off mode, may include a creep mode in which the motor torque changes within a predetermined range for a specific time. In this case, the anti-jerk mode may include at least two modes of braking mode, tip-in mode, tip-out mode, and creep mode.

[0091] Once the anti-jerk mode is determined, the second control 30 next determines, using the determined vehicle weight received from the first control 20, the anti-jerk torque value in S14' to S19, taking into account the current vehicle weight, and next determines a final motor torque command in S20 by compensating the required torque command received from the first control 20 with the anti-jerk torque.

[0092] When the final motor torque command is determined as described above, the second controller 30 in S21 operates the inverter according to the motor torque command and controls the motor 41.

[0093] Referring to Fig. 2A and Fig.In S14', the model speed of the motor is calculated in the second control 30 to determine the anti-jerk torque value, taking into account the vehicle weight, and in S15 the speed deviation between the model speed and the actual speed of the motor is calculated and the motor vibration value is obtained by the deviation between the model speed and the actual speed of the motor.

[0094] Furthermore, as described below, in the second control unit 30, a current load level is determined in S16 based on the determined vehicle weight, a dead zone is determined that corresponds to the specified anti-jerk mode, and in S17 it is checked whether the speed deviation is included in the dead zone.

[0095] Next, if the speed deviation in the dead zone is not included, a torque factor value corresponding to the anti-jerk mode and the load level is determined in S18 in the second control 30, and then the anti-jerk torque value is determined in S19 using the engine vibration value and the torque factor value.

[0096] The process of determining the anti-jerk torque is described in more detail below.

[0097] Anti-jerk torque is a torque that prevents the vibrations (shocks and jerks) of a drivetrain that can occur during acceleration and deceleration of a vehicle. The anti-jerk torque of a motor-driven vehicle (an electric vehicle) can be calculated using the vehicle's real-time driving information. This driving information can include information on wheel speed and motor speed, respectively, detected by sensors 11 and 12.

[0098] In addition to engine speed and wheel speed, the acceleration value of a vehicle can be used. The acceleration, together with the wheel speed, can be used to calculate the model engine speed.

[0099] The motor speed is the speed of the motor as detected by a motor speed sensor 13. In the anti-jerk control system, the motor speed detected by the motor speed sensor 13 is the actual speed of the motor.

[0100] The motor speed sensor 13 can be a normal resolver mounted on the motor 41 (the drive motor) of an electric vehicle.

[0101] The wheel speed is the rotational speed of the wheel detected by the wheel speed sensor 11. The wheel speed is used to calculate the model speed of the motor, which in turn allows the anti-jerk torque to be calculated in the second controller 30 based on the actual speed and the model speed of the motor.

[0102] As described below, in the present disclosure the anti-jerk torque is obtained according to the vehicle weight by further using the determined vehicle weight obtained from the first control 20.

[0103] In an electric vehicle (a motor-driven vehicle) where anti-jerk control is implemented, it can be determined that the motor torque command for motor control is the sum of the required torque command according to the driver's requirements and the anti-jerk torque for vibration reduction, as in Equation 2 (S20 of below). Fig. 2B). This can be applied in the same way to the present disclosure. Motor torque command = required torque command + anti-torque + jerk torque

[0104] In calculating the anti-jerk torque, the model speed denotes the motor speed at which vibrations are ignored and can denote an equivalent wheel speed obtained by converting the wheel speed detected by the wheel speed sensor 11 into the speed of the motor 41 using a gear ratio between the motor and the wheel.

[0105] The model speed can be described as the value of a reference speed required for the motor's anti-jerk control, which is a control system that compensates for motor speed fluctuations. For such anti-jerk control, the reference speed is necessary to determine the magnitude of the motor speed fluctuation.

[0106] Such a model speed can be a speed that is calculated from the wheel speed to a value related to the motor.

[0107] In addition to wheel speed, a vehicle acceleration value can also be used to calculate the model speed, thus improving the performance of the anti-jerk control. Accordingly, the anti-jerk control can be pre-executed by predicting the change in model speed, which is calculated using the acceleration value.

[0108] Since such a calculation process for the model speed is also a technology known from the familiar anti-jerk control, a detailed description of it is omitted in this description.

[0109] The method for calculating the model rotational speed includes a wheel speed-based calculation method and a wheel speed determination calculation method as a method for more active use of the anti-jerk mechanism. The acceleration value is used during wheel speed determination.

[0110] Furthermore, as described above, the anti-jerk torque in the second control 30 can be determined by the actual rotational speed or velocity and model rotational speed of the motor 41 and the value corresponding to the determined vehicle weight (i.e., the determined vehicle weight of the first control).

[0111] In particular, when the motor speed sensor 13 detects a current motor speed (that is, the current actual speed of a motor) and the current model speed of the motor is obtained, which is based on the wheel speed detected by the wheel speed sensor 11, the anti-jerk torque can be calculated based on the model speed and the actual speed of the motor and the determined vehicle weight of the first control.

[0112] In the present disclosure, it can be determined that the anti-jerk torque corresponds to the deviation between the model speed and the actual speed of the motor. Using the deviation between the model speed and the actual speed of the motor, the motor vibration value can be obtained, and the anti-jerk torque value is determined based on the motor vibration value.

[0113] The anti-jerk torque value can be calculated by multiplying the engine vibration value by the torque factor value. The torque factor value is determined according to the current vehicle weight (the measured vehicle weight).

[0114] In the present disclosure, the process and method for obtaining the engine vibration value using the deviation between the model speed and the actual speed of the engine does not differ from the known process and method for obtaining the engine vibration value, and the engine vibration value can be determined by the known process and known method for calculation.

[0115] However, in the present disclosure for effective anti-jerk control, the anti-jerk mode can be assigned to several modes according to the driving conditions. The anti-jerk mode is classified to differentiate the anti-jerk torque according to the driving condition of a vehicle and can be a mode corresponding to braking, acceleration, a constant speed, or an anti-jerk locking condition.

[0116] As a specific example, the anti-jerk mode in the present disclosure can include the anti-jerk off mode (the mode “AJ 0”), the braking mode (the mode “AJ 1”), the tip-in mode (the mode “AJ 2”) and the tip-out mode (the mode “AJ 3”).

[0117] The anti-jerk off mode is an anti-jerk mode in which the anti-jerk control is deactivated, and the brake mode is an anti-jerk mode at a time when braking is performed by the driver pressing a brake pedal.

[0118] Furthermore, the Tip-In mode is the anti-jerk mode (torque increase) at a time when the driver presses the accelerator pedal, and the Tip-Out mode is the anti-jerk mode (torque reduction) at a time when the driver takes their foot off the accelerator pedal.

[0119] In the preceding description, the anti-jerk mode was described as comprising a total of four modes; however, this is merely an example, and it should be noted that the present disclosure is not limited to this. The anti-jerk mode can be modified in various ways with regard to its nature or number, the definitions of each of its modes, and the driving conditions intended for each mode.

[0120] Furthermore, an anti-jerk dead zone may be defined in the present disclosure, which is a speed range in which the anti-jerk control is not used based on the speed deviation between the model speed and the actual motor speed. The anti-jerk dead zone may be defined based on the speed deviation for each anti-jerk mode.

[0121] Here, the minimum and maximum speeds of a speed deviation range, corresponding to the dead zone for each anti-jerk mode, are predetermined, and a speed range between the minimum and maximum speeds specified for each anti-jerk mode is a dead zone for each mode in which the anti-jerk is deactivated.

[0122] In the present disclosure, the dead zone is an anti-jerk off section that is defined to prevent an anti-jerk malfunction due to disturbances at the extremely low speed of the motor.

[0123] Furthermore, anti-jerk control in motor-driven vehicles is fundamentally used to solve problems such as drivetrain vibrations caused by fluctuations in engine speed. While the engine speed fluctuates, anti-jerk torque must be applied to the vehicle to prevent such problems.

[0124] Under normal driving conditions, however, engine speed fluctuations rarely occur or disappear due to changes in vehicle weight. Typical cases affected by changes in vehicle weight include a vehicle starting from a stationary state and a vehicle operating at low speed or engine speed.

[0125] In the case where a vehicle is heavy, if the driver enters the intention to start the vehicle and transmits the intention to the vehicle, that is, if he gives a driving input to start the vehicle, the engine speed increases, but the vehicle is heavy and it may not move.

[0126] Compared to a light vehicle, this phenomenon occurs over a longer period before a vehicle wheel actually moves. In this case, the engine speed fluctuates.

[0127] Furthermore, if a vehicle is heavy, the torque factor applied to the anti-jerk torque is increased to suppress engine speed fluctuations. The same applies in heavy traffic, especially when a vehicle starts moving from a low speed or engine speed on an uphill road or when a vehicle is reversing on a downhill road.

[0128] Accordingly, it is necessary to use the torque factor value that takes the vehicle weight into account when calculating the anti-jerk torque. Therefore, in this disclosure, the torque factor value corresponding to the current vehicle weight is determined and used to calculate the anti-jerk torque.

[0129] For this purpose, the present disclosure provides the second control unit 30 to determine the anti-jerk mode according to a current driving condition using the driving information of a vehicle, and to determine the current loading level of a vehicle, i.e., the determined vehicle weight of the first control unit, using a current vehicle weight value determined by the first control unit 20.

[0130] In addition, the second control 30 determines whether the speed deviation between the model speed and the actual speed of the motor 41 corresponds to the current load level and the anti-jerk dead zone defined in the anti-jerk mode.

[0131] If the second control 30 determines that the rotational speed deviation corresponds to the anti-jerk dead zone, the second control 30 does not execute the anti-jerk control by maintaining the anti-jerk control in an inactive state.

[0132] Alternatively, the second controller 30 executes the anti-jerk control if it determines that the speed deviation does not correspond to the anti-jerk dead zone. In this case, the torque factor value corresponding to the current load level and anti-jerk mode is determined, and the anti-jerk torque is calculated by multiplying the motor vibration value, which corresponds to the speed deviation between the model speed and the actual motor speed, by the torque factor value.

[0133] In the present disclosure, a vehicle weight range is divided into a plurality of sections, such that, based on the vehicle weight determined by the first controller 20, the current load level of a vehicle can be determined by the second controller 30, and then the load level of the vehicle is predetermined for each subdivided section. The information for each weight section is input to the second controller 30 and stored therein for each load level.

[0134] In the second control unit 30, a variety of load levels are defined, each corresponding to a different vehicle weight range. For example, the entire weight range of the vehicle, which can be changed when a passenger is being transported or cargo is being loaded, including an empty state, can be divided into a total of four levels: an empty level, a first load level, a second load level, and a third load level.

[0135] In this case, the third loading level in the vehicle weight can be defined as the section of the greatest weight, the second loading level can be defined as the section of the next greatest weight, and the first loading level can be defined as the section of the least weight except for the empty state.

[0136] Depending on the characteristics of a vehicle being used, the weight range corresponding to each load level may vary, and not every load level is defined as a specific weight range.

[0137] Furthermore, based on the vehicle weight value determined by the first controller 20, the second controller 20 determines the load level according to the current weight value. To prevent frequent changes in the load levels, hysteresis is preferably defined, which has different limit values ​​for entering and leaving each load level, with the limit values ​​defining the respective load levels.

[0138] Table 1 below shows a map in which the torque factor value for each anti-jerk mode is specified when the vehicle's load level is in an empty state, and Table 2 and Table 3 show a map in which a minimum dead zone speed is specified for each anti-jerk mode, and a map in which a maximum dead zone speed is specified for each anti-jerk mode when the vehicle's load level is in an empty state. [Table 1] Anti-Juck (AJ) mode 0 1 2 3 . torque factor 0 0,3 0,2 . . [Table 2] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 -7 -5 . . [Table 3] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 7 5 . .

[0139] According to the examples in Table 2 and Table 3, if the speed deviation (RPM), which is the difference between the model speed and the actual engine speed, is between minimum speed -7 and maximum speed 7 (dead zone is -7 to 7 RPM), in a case where a vehicle is empty and the anti-jerk mode is the braking mode (“AJ 1”), the anti-jerk control will not be executed and will be disabled.

[0140] Furthermore, according to the examples in Table 2 and Table 3, if the speed deviation (RPM) is between minimum speed -5 and maximum speed 5 (dead zone is -5 to 5 RPM), in the case where the vehicle is empty and the anti-jerk mode is the Tip-In mode (“AJ 2”), the anti-jerk control is not executed and is deactivated.

[0141] Furthermore, according to the example in Table 1, in the case where the vehicle is empty, the torque factor value is determined to be 0.3 in the case of braking mode, and the torque factor value is determined to be 0.2 in the case of tip-in mode.

[0142] Next, Table 4 below shows a map in which the torque factor value is specified for each anti-jerk mode when the vehicle's load stage is the first load stage, and Tables 5 and 6 each show, in the case of the first load stage, a map in which the minimum dead zone speed is specified for each anti-jerk mode, and a map in which the maximum dead zone speed is specified for each anti-jerk mode. [Table 4] Anti-Juck (AJ) mode 0 1 2 3 . torque factor 0 0,3 0,3 . . [Table 5] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 -5 -5 . . [Table 6] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 7 5 . .

[0143] In the present disclosure, the torque factor value and the dead zone are determined by the characteristic maps, that is, one characteristic map in which the torque factor value is defined according to the load level and the anti-jerk mode, and one characteristic map in which the minimum speed and the maximum speed of the dead zone are defined for each anti-jerk mode. The characteristic maps are pre-entered and stored in the second controller 30 to be used.

[0144] According to the examples in Table 5 and Table 6, if the speed deviation (RPM) is between the minimum speed -5 and the maximum speed 7 (the dead zone is -5 to 7 RPM), in a case where the determined vehicle weight corresponds to the first loading stage and the anti-jerk mode is the braking mode (“AJ 1”), the anti-jerk control is not executed and is deactivated.

[0145] Furthermore, according to the examples in Table 5 and Table 6, if the speed deviation (RPM) is between the minimum speed -5 and the maximum speed 5 (the dead zone is -5 to 5 RPM), in a case where the determined vehicle weight corresponds to the first loading stage and the anti-jerk mode is the Tip-In mode (“AJ 2”), the anti-jerk control is not executed and is deactivated.

[0146] Furthermore, according to the example in Table 4, in the first loading stage, in the case of braking mode, it is determined that the torque factor value is 0.3, and also in the case of tip-in mode, it is determined that the torque factor value is 0.3.

[0147] Next, Table 7 below shows a map in which the torque factor value is specified for each anti-jerk mode when the vehicle's load stage is the second load stage, and Tables 8 and 9 each show, in the case of the second load stage, a map in which the minimum dead zone speed is specified for each anti-jerk mode, and a map in which the maximum dead zone speed is specified for each anti-jerk mode. [Table 7] Anti-Juck (AJ) mode 0 1 2 3 . torque factor 0 0,4 0,3 . . [Table 8] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 -3 -3 . . [Table 9] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 7 5 . .

[0148] According to the examples in Table 8 and Table 9, if the speed deviation (RPM) is between the minimum speed -3 and the maximum speed 7 (the dead zone is -3 to 7 RPM), in a case where the determined vehicle weight corresponds to the second load stage and the anti-jerk mode is the braking mode (“AJ 1”), the anti-jerk control is not executed and is deactivated.

[0149] Furthermore, according to the examples in Table 8 and Table 9, if the speed deviation (RPM) is between the minimum speed -3 and the maximum speed 5 (the dead zone is -3 to 5 RPM), in a case where the determined vehicle weight corresponds to the second load stage and the anti-jerk mode is the Tip-In mode (“AJ 2”), the anti-jerk control is not executed and is deactivated.

[0150] Furthermore, according to the example in Table 7, in the second loading stage, in the case of braking mode, the torque factor value is determined to be 0.4, and in the case of tip-in mode, the torque factor value is determined to be 0.3.

[0151] Next, Table 10 below shows a map in which the torque factor value is specified for each anti-jerk mode when the vehicle's load level is the third load level, and Tables 11 and 12 each show, in the case of the third load level, a map in which the minimum dead zone speed is specified for each anti-jerk mode, and a map in which the maximum dead zone speed is specified for each anti-jerk mode. [Table 10] Anti-Juck (AJ) mode 0 1 2 3 . torque factor 0 0,5 0,4 . . [Table 11] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 -2 -2 . . [Table 12] Anti-Juck (AJ) mode 0 1 2 3 . Speed ​​deviation (RPM) 0 7 5 . .

[0152] According to the examples in Table 11 and Table 12, if the speed deviation (RPM) is between minimum speed -2 ​​and maximum speed 7 (the dead zone is -2 to 7 RPM), in a case where the determined vehicle weight corresponds to the third load stage and the anti-jerk mode is the braking mode (“AJ 1”), the anti-jerk control is not executed and is deactivated.

[0153] Furthermore, according to the examples in Table 11 and Table 12, if the speed deviation (RPM) is between the minimum speed -2 ​​and the maximum speed 5 (the dead zone is -2 to 5 RPM), in a case where the determined vehicle weight corresponds to the third load stage and the anti-jerk mode is the Tip-In mode (“AJ 2”), the anti-jerk control is not executed and is deactivated.

[0154] Furthermore, according to the example in Table 10, in the third loading stage, in the case of braking mode, the torque factor value is determined to be 0.5, and in the case of tip-in mode, the torque factor value is also determined to be 0.4.

[0155] In Tables 1 to 12, " · " does not denote 0 (zero), but denotes any number.

[0156] As can be seen from Tables 1 to 12, in the present disclosure the torque factor value for determining the anti-jerk torque for each load stage and the speed deviation range of the dead zone in which the anti-jerk control is deactivated are predetermined, and furthermore the torque factor value and the speed deviation range of the dead zone are predetermined for each anti-jerk mode.

[0157] The values ​​in Tables 1 to 12 are examples and the present disclosure is not limited to them. The anti-jerk mode, the torque factor for each load level, the dead zone speed deviation range, and the minimum and maximum dead zone speeds can be modified and adjusted appropriately according to the vehicle characteristics.

[0158] In cases where a vehicle is relatively light, excessive application of anti-jerk torque can induce excessive vibrations in the drivetrain. Accordingly, the torque factor value can be set lower when the vehicle weight corresponds to a lower load class, and the speed deviation range, corresponding to the dead zone, can be set to a wider range.

[0159] In addition, the torque factor value can be set higher if the vehicle weight corresponds to a higher load class, and the speed deviation range, which corresponds to the dead zone, can be set as a narrower range.

[0160] Each value in Tables 1 to 12 can be changed according to the vehicle characteristics and must therefore be determined based on data obtained from conducting tests and evaluations on related vehicles beforehand.

[0161] For example, the characteristics of the anti-jerk mode can be set to make the speed deviation range of the dead zone wider or narrower.

[0162] Furthermore, the reason the dead zone is differentiated according to vehicle weight (load level), as described above, is that there are times when the anti-jerk control must be actively executed, especially when the vehicle is heavily loaded. When the anti-jerk control is actively executed, the absolute values ​​of the minimum and maximum engine speeds within the dead zone are kept small, and the engine speed deviation range within the dead zone, in which the anti-jerk control is not active, is reduced.

[0163] Although the embodiment of the present disclosure has been described in detail, the scope of protection of the claims of the present disclosure is not limited thereto, and it is evident to the person skilled in the art that different modifications, additions and substitutions are possible without deviating from the scope of protection and inventive concept of the disclosure as disclosed in the attached claims.

Claims

[1] Anti-jerk control method for an electric vehicle, the method comprising: Determining a vehicle's weight through a control system based on vehicle driving information collected from a vehicle; Determining a required torque command from a driver by the control unit based on the vehicle driving information collected by the vehicle; Determine, by controlling, an anti-jerk torque according to the vehicle weight based on a calculated speed deviation and the determined vehicle weight information after calculating the speed deviation between a model speed and an actual engine speed; and Control, by means of the control, of a drive motor according to a compensated motor torque command by compensating the required torque command with the anti-jerk torque, wherein a weight determination prohibition condition is specified in the control system, wherein the weight determination prohibition condition includes a condition in which a gradient of a roadway on which the vehicle travels is at least a target value, and a condition in which a steering angle is at least a target angle, where determining the vehicle weight, determining the required torque command, determining the anti-jerk torque and controlling the drive motor are only performed if the weight determination prohibition condition is not met. [2] The method of claim 1, further comprising: Determine, by controlling, an anti-jerk mode that corresponds to a current driving condition, from a variety of predefined anti-jerk modes, based on the driving information collected by the vehicle. where the anti-jerk torque is determined according to the vehicle weight A motor vibration value is obtained from the calculated speed deviation. A torque factor value is determined based on the calculated vehicle weight and the selected anti-jerk mode, and The anti-jerk torque is determined by the obtained engine vibration value and the determined torque factor value. [3] Method according to claim 2, wherein in the control system, when a plurality of load levels are specified which comprise different vehicle weight ranges, and a load level is determined which corresponds to the determined vehicle weight, the torque factor value is determined which corresponds to the determined anti-jerk mode and the load level. [4] Method according to claim 3, wherein the torque factor value is determined by the control system by a characteristic map in which the torque factor value is defined according to the anti-jerk mode and the load level. [5] Method according to claim 3, wherein in the control the anti-jerk mode and a dead zone, which is a speed deviation range in which the anti-jerk control is deactivated, are predefined for each load level, and if the speed deviation calculated by the model speed and the actual speed of the motor is contained in a speed deviation range of a dead zone corresponding to a current anti-jerk mode and a current load level, determining the anti-jerk torque according to the vehicle weight, and controlling the drive motor according to the compensated motor torque command are not performed. [6] Method according to claim 5, wherein in the control the speed deviation range of the dead zone corresponding to the current anti-jerk mode and the current load level is designed to be used using a characteristic map in which the anti-jerk mode and minimum speed and maximum speed of the speed deviation range are specified for each load level. [7] Method according to claim 5, wherein, if a specified vehicle weight corresponds to a higher loading level of the plurality of loading levels, the rotational speed deviation range of the dead zone is specified as a narrower range. [8] Method according to claim 5, wherein, if a specified vehicle weight corresponds to a higher loading level of the plurality of loading levels, the torque factor value is specified as a higher value. [9] Method according to claim 2, wherein the plurality of anti-jerk modes comprises at least two modes of a braking mode at a time when the driver presses on a brake pedal, a tip-in mode at a time when the driver presses on an accelerator pedal, a tip-out mode at a time when the driver takes his foot off the accelerator pedal, and a creep mode in which the engine torque changes within a predetermined range for a certain time. [10] Method according to claim 1, wherein a plurality of load levels are defined in the control system, which cover different vehicle weight ranges; When determining the anti-jerk torque according to the vehicle weight using the calculated speed deviation, an engine vibration value is obtained; when a load level is determined that corresponds to the determined vehicle weight, a torque factor value is determined that corresponds to the determined load level; and The anti-jerk torque is determined using the obtained engine vibration value and the determined torque factor value. [11] Method according to claim 10, wherein a dead zone, which is a speed deviation range in which the anti-jerk control is deactivated, is predefined in the control for each load stage, and if the speed deviation calculated using the model speed and the actual speed of the motor is contained in the speed deviation range of the dead zone corresponding to a current load stage, the anti-jerk control is inactive in the control. [12] Method according to claim 11, wherein, if a specified vehicle weight corresponds to a higher loading level of the plurality of loading levels, the rotational speed deviation range of the dead zone is specified as a narrower range. [13] Method according to claim 11, wherein, if a specified vehicle weight corresponds to a higher load level of the plurality of load levels, the torque factor value is specified as a higher value. [14] Non-volatile computer-readable medium containing program instructions that are executed by a processor, wherein the computer-readable medium has: Program instructions that determine the vehicle weight based on vehicle driving information collected from a vehicle; Program instructions that determine a required torque command from a driver based on the vehicle driving information collected by the vehicle; Program instructions that determine an anti-jerk torque based on the calculated speed deviation and the determined vehicle weight information after calculating the speed deviation between a model speed and an actual engine speed; and Program instructions that control a drive motor according to a compensated motor torque command by compensating the required torque command with the anti-jerk torque, wherein a weight determination prohibition condition is specified in the control system, wherein the weight determination prohibition condition includes a condition in which a gradient of a roadway on which the vehicle travels is at least a target value, and a condition in which a steering angle is at least a target angle, where determining the vehicle weight, determining the required torque command, determining the anti-jerk torque and controlling the drive motor are only performed if the weight determination prohibition condition is not met.

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