Device and method for generating driving torque command for operating a hybrid electric vehicle

Abstract

A drive torque command generating device and method for operating a hybrid vehicle can use the engine speed, motor speed and wheel speed detected by the engine speed detector, the motor speed detector and the wheel speed detector respectively, and the motor torque command generated in the previous time period to obtain a torsional state observation value together, and generate an engine torque command and a motor torque command for the drive torque command based on the drive input value input by the drive input detector and the torsional state observation value.

Description

Technical Field

[0001] The present disclosure generally relates to a drive torque command generating device and method for operating a hybrid electric vehicle, and more specifically, to a drive torque command generating device and method that can achieve a quick response in response to a driver's drive input while effectively reducing noise, vibration and harshness (NVH) problems caused by torsion and play in the drive system. Background Art

[0002] A hybrid electric vehicle (HEV) is a vehicle that is propelled by an engine and an electric motor. The HEV hybrid vehicle can be propelled by efficiently combining the power of the engine and the power of the electric motor.

[0003] Figure 1 (Prior Art) A configuration of a hybrid system of an HEV is described, and more specifically, a powertrain configuration of a transmission mounted electric device (TMED) HEV is described, in which a transmission 14 is arranged on the output side of a drive motor (MG1) 13.

[0004] like Figure 1 As described, the hybrid system includes an engine 11 and a drive motor 13 arranged in series as power sources for propelling the vehicle, an engine clutch 12 configured to connect or disconnect power between the engine 11 and the drive motor 13, a transmission 14 that transmits power from the engine 11 and the drive motor 13 to the drive shaft by speed conversion, and a starter generator (MG2) 15 directly connected to the engine 11 in a manner that can transmit power.

[0005] In addition to this configuration, an inverter 16 and a motor control unit (MCU) 17 that operates and controls the drive motor 13 , a high-voltage battery 18 that provides operating power to the drive motor 13 , and a battery management system (BMS) 19 that controls and manages the battery 18 are also provided.

[0006] In this configuration, the engine clutch 12 connects or disconnects power between the engine 11 and the drive motor 13 of the vehicle by a closing or opening operation.

[0007] In addition, a battery 18 serving as a propulsion source (or power source) of the vehicle is chargeably / dischargeably connected to the drive motor 13 and the starter generator 15 via an inverter 16. The inverter 16 converts direct current (DC) of the battery 18 into three-phase alternating current (AC) and applies the three-phase AC to the drive motor 13 and the starter generator 15 so as to operate the drive motor 13 and the starter generator 15.

[0008] The starter generator 15 is a device that performs the combined functions of a starter motor and a generator. The starter generator 15 starts the engine 11 by transmitting power to the engine 11 via a power transmission device (e.g., a belt or a pulley), generates electric energy using torque received from the engine, or charges the battery 18 with the electric energy generated when generating electricity.

[0009] The BMS 19 collects battery status information such as voltage, current, temperature, state of charge (SOC, in %) of the battery 18. The BMS 19 provides the collected battery status information to other controllers in the vehicle or performs charge / discharge control on the battery 18 using the collected battery status information.

[0010] Additionally, the vehicle's response to a driver's driving inputs, such as manipulation of an accelerator pedal or a brake pedal, and its ability to reduce noise, vibration, and harshness (NVH) issues caused by significant changes in driving force are in a trade-off relationship.

[0011] In addition, with respect to generating a driving torque command (or driving force command) to a vehicle drive source, such as generating a torque command to an engine or a torque command to a driving motor in a vehicle, a rate limiter or filter is used, which has various conditions as parameters to generate an optimal torque command, through which the above-mentioned trade-off relationship can be eliminated.

[0012] However, developing a rate limiter or filter in which various conditions are considered requires an excessive number of processing steps, which is problematic.

[0013] In recent years, a dual or diversified method is used to generate a drive torque command according to a driving mode or condition in order to provide driving customized control according to the driver's wishes. In this case, the number of processing steps may increase significantly depending on the number of diversified types, which is problematic.

[0014] Korean Patent No. 10-1795285 discloses an engine-motor vibration reduction apparatus and method for generating a reverse phase torque using a motor by extracting a vibration component based on an engine-side rotation speed and comparing the vibration component with a motor-side rotation speed.

[0015] The apparatus and method according to Korean Patent No. 10-1795285 can actively reduce vibrations generated by engine knock by directly adjusting the phase within a frequency range.

[0016] However, the method disclosed in Korean Patent No. 10-1795285 can only process the frequency corresponding to the vibration caused by engine knock, but does not include any ability to respond to NVH problems generated by the driver's driving input. Therefore, it is difficult to perform a control process for reducing the torsion of the torsion damper and reducing the play of the drive system.

[0017] In addition, since the reverse phase control is performed only in the frequency range and not in the time range, the torsion of the torsion damper generated by the driving input of the driver cannot be reduced in the time range.

[0018] Real-time phase reversal control must be performed to achieve this reduction. However, real-time phase reversal control is difficult to perform due to the insufficient torque tracking capability of the engine.

[0019] The foregoing content is only intended to help understand the background of the present disclosure, but is not intended to mean that the present disclosure falls within the scope of the relevant technologies known to those skilled in the art. Summary of the invention

[0020] Therefore, the present disclosure proposes a drive torque command generating device and method for operating a hybrid electric vehicle (HEV), which is capable of obtaining a rapid response of the vehicle in response to the driver's drive input, while effectively reducing noise, vibration and harshness (NVH) problems caused by the torsion and clearance of the drive system, for example, even in the case of significant changes in the drive force caused by the driver's drive input.

[0021] According to one aspect of the present disclosure, a drive torque command generating device for a hybrid electric vehicle includes: a drive input detector for detecting a drive input value of a driver, the drive input value including a pedal input value in response to operating an accelerator pedal; an engine speed detector for detecting an engine speed of a vehicle engine; a motor speed detector for detecting a motor speed of an electric motor used as a drive source for the vehicle; a wheel speed detector for detecting a wheel speed of a wheel of the vehicle; and a controller for using a measured engine speed, a measured motor speed and a measured wheel speed detected by the engine speed detector, the motor speed detector and the wheel speed detector, respectively, and a motor torque command generated in a previous period to obtain a torsional state observation value together, and generating an engine torque command and a motor torque command for a drive torque command based on the drive input value and the torsional state observation value input by the drive input detector.

[0022] According to another aspect of the present disclosure, a method for generating a drive torque command for a hybrid electric vehicle includes: detecting a drive input value of a driver by a drive input detector, the drive input value of the driver including a pedal input value in response to manipulating an accelerator pedal; detecting an engine speed of a vehicle engine by an engine speed detector; detecting a motor speed of an electric motor used as a drive source for the vehicle by a motor speed detector; detecting a wheel speed of the vehicle by a wheel speed detector; and obtaining a torsional state observation value by a controller using the measured engine speed, the measured motor speed and the measured wheel speed detected by the engine speed detector, the motor speed detector and the wheel speed detector, respectively, and the motor torque command generated in a previous time period; and generating an engine torque command and a motor torque command for a drive torque command based on the drive input value and the torsional state observation value input by the drive input detector by the controller.

[0023] According to the present disclosure, the drive torque command generating device and method of the HEV can obtain a rapid response of the vehicle in response to the driver's drive input (for example, the driver's manipulation of the accelerator pedal), while effectively reducing NVH problems caused by torsion and clearance of the drive system, even when the drive input causes significant changes in the drive force.

[0024] In addition, according to the present disclosure, in the case of overcoming the NVH problem caused by the torsion and play of the drive system, the difficulty of setting the torque command filter or the torque gradient in a case-specific manner can be overcome by considering a variety of factors (which are problems of the prior art solution using a rate limiter or a filter) and a large number of processing steps. In addition, since a torque command suitable for a specific time point can be generated in real time, it can be expected to improve efficiency.

[0025] In particular, according to the present disclosure, a drive torque command can be generated by pre-observing the result of the clearance or vibration of the drive system according to the change in torque before the torque is actually generated, thereby effectively reducing NVH problems, even when there is a unique control delay time in the engine or motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other objects, features and other advantages of the present disclosure will be more clearly understood through the following detailed description when taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 (Prior Art) is a system configuration diagram of a typical hybrid electric vehicle (HEV).

[0028] Figure 2 and Figure 3(Prior Art) is a view explaining a prior art control method by which torque gradient limitation is performed;

[0029] Figure 4 and Figure 5 is a diagram illustrating a feedback control method using a drive torque command generated according to the present disclosure;

[0030] Figure 6 is a block diagram illustrating a configuration of a drive torque command generating device according to the present disclosure; and

[0031] Figure 7 1 is a block diagram illustrating an engine speed observer and a motor speed observer of a torque observer in a drive torque command generating apparatus according to the present disclosure. DETAILED DESCRIPTION

[0032] It should be understood that the term "vehicle" or "vehicle-like" or other similar terms used herein generally include motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including various ships, aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle having two or more sources of power, such as a vehicle having both gasoline power and electric power.

[0033] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. As used herein, the singular forms "a / an" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that when the term "comprises / comprising" is used in this specification to specify the presence of the features, integers, steps, operations, elements and / or components, it does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word "comprise" and variations such as "comprises / comprising" will be understood to imply the inclusion of the stated elements, but not to exclude any other elements. In addition, the terms "unit", "-piece", "-device" and "module" described in the specification refer to units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof.

[0034] In addition, the control logic of the present disclosure may be practiced as non-transitory computer-readable media on a computer-readable medium containing executable program instructions executed by a processor, controller, etc. Examples of computer-readable media include, but are not limited to, ROM, RAM, compact disk (CD)-ROM, magnetic tape, floppy disk, flash drive, smart card, and optical data storage device. The computer-readable medium may also be distributed in a network-coupled computer system so that the computer-readable medium is stored and executed in a distributed manner, for example, by a telematics server or a controller area network (CAN).

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily put the present disclosure into practice. However, the present disclosure is not limited to the embodiments described herein and may be practiced in other forms.

[0036] The flywheel-integrated torsional damper is located between a vehicle driving source, ie, an engine and a driving motor (hereinafter referred to as a "motor"), and serves to damp vibration of the engine.

[0037] However, sudden changes in engine torque or motor torque can cause excessive torsion on the shock absorber, thereby causing noise, vibration and harshness (NVH) problems in the drive system. To overcome these problems, a limiting device such as a rate limiter or filter is used to limit the rate of change of the engine torque or motor torque (or the rate of change of the torque command).

[0038] That is, using a rate limiter or a filter having various conditions as parameters to generate an optimal driving torque command (or driving force command) in a hybrid electric vehicle (HEV) can remove problems caused by twisting of the driving system with the command.

[0039] However, this method of limiting the rate of change (i.e., gradient) does not provide a quick response. As a result, there is a significant difference between the vehicle behavior expected by the driver and the actual vehicle behavior. In addition, there may be a lag or delay in the acceleration or deceleration response, thereby reducing driving performance, which is problematic.

[0040] Figure 2 and Figure 3 is a view explaining a related art control method by which torque gradient limitation is performed.

[0041] exist Figure 2 and Figure 3 In the figure, APS and BPS represent accelerator position sensor and brake pedal sensor respectively.

[0042] like Figure 2As described, in the known method using torque gradient limitation, torque gradient control can be performed using a rate limiter to smoothly increase the engine torque command even when the driver suddenly manipulates the accelerator pedal (ie, even when the APS value suddenly increases).

[0043] However, even in the case where the torque gradient control is performed, there may be a difference between the engine speed and the motor speed due to the torsion of the drive shaft or the like.

[0044] In addition, since the above-mentioned torque gradient control is performed, a slowly rising engine torque command is generated, unlike the case where the driver suddenly depresses the accelerator pedal. Therefore, the operation of the engine is controlled by the slowly rising torque command, and the vehicle reaction to the increased acceleration (i.e., longitudinal acceleration) is slowed down.

[0045] Reference Figure 3 , the controller 10 controls the vehicle in response to a driving input (e.g., APS value and BPS value) such as manipulation of an accelerator pedal or a brake pedal by a driver. In particular, when determining a target torque for controlling the engine torque output, a control process is performed so that the rate limiter 9 in the controller 10 limits the gradient of the engine torque command according to variables such as the gear position, the engine torque command before correction, the wheel speed, the mode, the gear shift level / phase, and the charge / discharge state of the motor.

[0046] When the torque of the damper is calculated based only on the difference between the engine speed and the motor speed, a lag or time delay occurs between the point in time when the torque is measured and the point in time when the engine torque and the motor torque follow the command to reduce the torque.

[0047] Therefore, due to the phase difference, the effect of reducing the twist may not be significant or the twist may be increased unintentionally. In order to overcome these problems, it is necessary to estimate the twist amount in advance by considering the time delay.

[0048] In addition, in addition to the NVH problems caused by interference, most NVH problems in the drive system are caused by the play and torsion of the drive shaft caused by the gear meshing clearance in the drive system. Therefore, a control method for reducing the problems caused by the play, that is, a control method for reducing the play, is needed.

[0049] When the gradient of the torque command is controlled so that the torque command changes as smoothly and slowly as possible in response to the driver's manipulation of the accelerator pedal, the NVH problem in the driving system due to play or torsion may be removed to some extent.

[0050] However, the gentle and slow change of torque as described above does not provide a quick response, thereby increasing the difference between the vehicle behavior expected by the driver and the actual vehicle behavior. This can cause a lag or delay in the acceleration or deceleration response, thereby reducing driving performance.

[0051] refer to Figure 2 It can be understood that even when the driver suddenly presses the accelerator pedal (i.e., even when the APS value suddenly increases), the engine torque command increases at a gentle slope and after the accelerator pedal is pressed, the vehicle acceleration (i.e., longitudinal acceleration) increases with a time delay.

[0052] In order to overcome this trade-off between the vehicle's response and the NVH problem caused by the significant change in driving force, in the prior art, in order to apply a rate limiter or filter, additional work is required: experimentally discovering the torque gradient value and filter constant optimized for each situation. At this time, the integrity of all variables such as gear, engine torque (or torque command), wheel speed, mode, gear shift level / phase, and charge / discharge state of the motor must be considered.

[0053] Therefore, in order to overcome the above problems, the present disclosure proposes a method for generating an engine torque command based on the torque of a drive system, which method enables the optimal torque command for overcoming the NVH problem to be generated in real time.

[0054] Hereinafter, a driving torque command generating apparatus and method according to the present disclosure will be described in more detail with reference to the accompanying drawings.

[0055] Figure 4 and Figure 5 is a view illustrating a feedback control method using a driving torque command generated according to the present disclosure. Figure 6 is a block diagram illustrating a configuration of a drive torque command generating device according to the present disclosure.

[0056] in addition, Figure 7 1 is a block diagram illustrating an engine speed observer and a motor speed observer of a torque observer in a drive torque command generating apparatus according to the present disclosure.

[0057] The driving torque command generating device according to the present disclosure includes: a driver input detector 101, which is used to detect the driving input value when the driver has input the driving input to the vehicle; an engine speed detector 104, which is used to detect the engine speed; a motor speed detector 105, which is used to detect the motor speed; a wheel speed detector 106, which is used to detect the wheel speed; and a controller 110, which is used to obtain a torsional state observation value, that is, a value obtained by observing the torsional state of the vehicle drive system, using information about the engine speed, the motor speed and the wheel speed detected and input by the engine speed detector 104, the motor speed detector 105 and the wheel speed detector 106 respectively, and generate a driving torque command based on the driving input value and the torsional state observation value input by the driving input detector 101.

[0058] The drive torque command includes an engine torque command and a motor torque command.

[0059] The driving input detector 101 may include a typical accelerator pedal sensor (APS) 102 and a brake pedal sensor (BPS) 103 , which are typical sensors for detecting an accelerator pedal input value and a brake pedal input value of a driver.

[0060] Here, the driving input value includes a driver's pedal input value in response to an accelerator pedal and a brake pedal manipulated by the driver, that is, an APS value and a BPS value indicating a pedal position, a displacement of pedal manipulation, and the like.

[0061] The APS value and the BPS value represent signal values ​​(or sensor values) represented by electric signals (or sensor signals) output by sensors (ie, APS and BPS).

[0062] The engine speed detector 104 for detecting the engine speed may be a typical sensor for detecting engine rotation, for example, an engine RPM sensor. In a typical HEV, the motor speed detector 105 for detecting the motor speed and the wheel speed detector 106 for detecting the wheel speed may be an angle sensor provided on the motor and a wheel speed sensor provided on the vehicle wheel, respectively.

[0063] In addition, the controller 110 may be a hybrid control unit (HCU) mounted on the HEV.

[0064] The controller 110 includes a target torque generator 111, which receives the driver's driving input value detected by the driving input detector 101, that is, the APS signal value and the BPS signal value. The target torque generator 111 generates a target torque with which the engine and the motor are controlled according to the detected driving input value, and outputs the target torque generated as described above.

[0065] Here, the target torque includes a target engine torque and a target motor torque, which are optimized when controlling the engine and the motor, respectively. The target torque is determined according to a driving input value of a driver.

[0066] In addition, the controller 110 also includes a first torque command generator 112, which determines a torque gradient based on current vehicle state information collected from the vehicle, and generates and outputs a feedforward torque command based on a target torque generated and output by a target torque generator 111, wherein the feedforward torque command is a torque value that is limited to change under the torque gradient determined above.

[0067] Here, the first torque command generator 112 includes a rate limiter 112a for limiting and controlling the torque gradient. When the torque gradient according to the vehicle state information is determined by the rate limiter 112a, the torque value that changes under the determined torque gradient is determined according to the target torque output by the target torque generator 111, and the torque value is output as a feedforward torque command.

[0068] Here, the first torque command generator 112 uses the target torque (i.e., the target engine torque and the target motor torque) input by the target torque generator 111 as input to determine the engine torque value and the motor torque value that change under the determined torque gradient, and outputs the engine torque value and the motor torque value as feedforward torque commands.

[0069] Therefore, the feedforward torque command includes a feedforward engine torque command and a feedforward motor torque command, and the rate limiter 112a uses the feedforward engine torque command to gradient limit the target engine torque, and the rate limiter 112a uses the feedforward motor torque command to gradient limit the target motor torque.

[0070] The gear position and the wheel speed may be used to implement vehicle state information, ie, variables by which the rate limiter 112a determines the torque gradient (ie, the gradient of the torque command). The torque gradient may be determined based on the gear position and the wheel speed.

[0071] According to the present disclosure, the rate limiter is any limiter that is not limited to using a specific method to limit and control the torque gradient, as long as the rate limiter can control the torque gradient according to the variable to a certain extent. A known rate limiter or a modified rate limiter having variables simplified in consideration of vehicle conditions or controller conditions, etc. can be used.

[0072] The controller 110 also includes a torsion observer 113, which receives the engine speed, motor speed and wheel speed detected by the engine speed detector 104, the motor speed detector 105 and the wheel speed detector 106 respectively, and the motor torque command generated by the drive torque command generator 115 in the previous period (this will be described later) and generates and outputs a torsion state observation value by observing (or estimating) the torsion state of the vehicle drive system based on the engine speed, motor speed and wheel speed and the drive torque command detected as described above.

[0073] The torsional state observation values ​​according to the present disclosure include the torsional angular velocity, torsional angular acceleration and torsional angle of the drive system obtained based on the detected engine speed, motor speed and wheel speed, and the engine torque command and motor torque command fed back as input values ​​by the drive torque command generator.

[0074] The torsional state observation value observed by the driving system includes the torsional state observation value observed by the shock absorber and the torsional state observation value observed by the transmission. The torsional state observation value of the shock absorber and the torsional state observation value of the transmission respectively include torsional angular velocity, torsional angular acceleration and torsional angle.

[0075] In addition, the controller further includes a second torque command generator 114 that generates and outputs a feedback torque command for reducing the torsion of the vehicle drive system based on the torque state observation value output by the torsion observer 113 (ie, the state observer).

[0076] In addition, the controller 110 further includes a driving torque command generator 115 which generates a final driving torque command through the feedforward torque command output by the first torque command generator 112 and the feedback torque command output by the second torque command generator 114 .

[0077] Here, the drive torque command generator 115 generates the final drive torque command by correcting the feedforward torque command to the same degree as the feedback torque command intended to reduce the twist.

[0078] The feedback torque command output by the second torque command generator 114 may include a feedback engine torque command (ie, a first feedback torque command regarding the engine), and a feedback motor torque command (ie, a second feedback torque command regarding the motor), such as a feedforward torque command.

[0079] The feedback engine torque command and the feedback motor torque command are determined as commands to generate engine torque and motor torque in a direction to reduce torsion of a drive system including a damper and a transmission. The drive torque command generator 115 determines a final drive torque command as a sum of the feedforward torque command and the feedback torque command.

[0080] That is, the sum of the feedforward engine torque command output by the first torque command generator 112 and the feedback engine torque command output by the second torque command generator 114 is determined by the driving torque command generator 115 as the final engine torque command.

[0081] In addition, the sum of the feedforward motor torque command output by the first torque command generator 112 and the feedback motor torque command output by the second torque command generator 114 is determined by the driving torque command generator 115 as a final motor torque command.

[0082] In the following, the components and processes of the drive torque command generating device will be further described. When the driver manipulates the accelerator pedal or the brake pedal, the drive input value in response to the accelerator pedal or the brake pedal manipulated by the driver is detected by the drive input detector 101. The drive input value detected by the drive input detector 101 is input to the controller 110 in real time.

[0083] During vehicle travel, the engine speed, motor speed and wheel speed are respectively detected by the engine speed detector 104, the motor speed detector 105 and the wheel speed detector 106. The detected engine speed, motor speed and wheel speed are input to the controller 110 in real time.

[0084] The detected driving input value is input to the target torque generator 111 of the controller 110 for generating the target torque. The detected engine speed, motor speed and wheel speed are input to the torsion observer 113 of the controller 110 for determining and generating the torsion state observation value of the driving system (i.e., the shock absorber and the transmission).

[0085] According to an embodiment of the present disclosure, the process in which the target torque generator 111 generates the target torque based on the driver's driving input value is no different from a known method performed in a typical HEV in which a controller generates a target value of the motor torque according to the driver's driving input value.

[0086] Since the above-mentioned method of generating the target torque by the target torque generator 111 can be regarded as a technical feature known in the art, a detailed description thereof will be omitted here.

[0087] In addition, the first torque command generator 112 generates a feedforward torque command as a value determined according to the torque gradient using the target torque generated by the target torque generator 111 as an input.

[0088] Therefore, the feed-forward torque command generated by the first torque command generator 112 is transmitted to the drive torque command generator 115 , where the feed-forward torque is used to generate a final motor torque command.

[0089] The torsion observer 113 (ie, the state observer of the controller 110 ) obtains a torsion state observation value using the engine speed, the motor speed, and the wheel speed together with the driving torque command generated in the previous period fed back by the driving torque command generator 115 as input information.

[0090] like Figure 7 As illustrated, the torque observer 113 may include an engine speed observer 113 a that observes the engine speed and a motor speed observer 113 b that observes the motor speed.

[0091] In the following description, the output value of the engine speed observer 113a (i.e., the engine speed observation value output by the engine speed observer 113a by observing the engine speed) is referred to as the "observed engine speed", and the output value of the motor speed observer 113b (i.e., the motor speed observation value output by the motor speed observer 113b by observing the motor speed) is referred to as the "observed motor speed".

[0092] In addition, in the following description, the engine speed detected by the engine speed detector 104 and the motor speed detected by the motor speed detector 105 are respectively referred to as "measured engine speed" and "measured motor speed" so that the detection value (or measurement value) is distinguished from the observation value.

[0093] In addition, the wheel speed detected by the wheel speed detector 106 is referred to as a “measured wheel speed”.

[0094] The torsion observer 113 determines a torsion state observation value indicating the torsion amount or degree by observing and estimating the torsion state based on the driving torque command (including the engine torque command and the motor torque command). In the process of observing and estimating the torsion state, the torsion observer 113 receives and uses the measured engine speed, the measured motor speed, and the measured wheel speed as real-time measurement results and the driving torque command (i.e., the engine torque command and the motor torque command) generated in the previous period fed back as input information by the driving torque command generator 115.

[0095] In particular, the engine speed observer 113a uses the speed observation value observed in the previous period as feedback information to observe the current engine speed. The engine speed observer 113a uses the observed engine speed observed in the previous period (i.e., feedback information) and the actually measured engine speed and engine torque command (fed back as input information by the drive torque command generator 115) to observe the current engine speed based on the model formula.

[0096] Additionally, the engine speed observer 113a may also use the measured motor speed in order to observe the current engine speed.

[0097] In addition, the engine speed observer 113a observes the output torque (ie, the observed damper torque). The output torque observed by the engine speed observer 113a may be used as the damper transfer torque by the motor speed observer 113b.

[0098] In addition, the engine speed observer 113a observes the output torque using information such as the torsional damper stiffness, as will be described later.

[0099] In the following description, the output torque observed by the engine speed observer 113a is referred to as "observed output torque".

[0100] Similarly, the motor speed observer 113b uses the speed observation value observed in the previous period as feedback information to observe the current motor speed. The motor speed observer 113b uses the motor speed observed in the previous period (i.e., feedback information), the actually measured motor speed and wheel speed, the motor torque command (i.e., information fed back from the drive torque command generator 115), and the shock absorber transfer torque to observe the current motor speed based on the model formula.

[0101] The motor speed observer 113b may use the observed output torque observed and output by the engine speed observer 113a as the damper transfer torque.

[0102] In addition, the motor speed observer 113b observes the output torque using information such as the transmission drive system stiffness, as will be described later.

[0103] The following formulas 1 to 5 are formulas used by the torsion observer 113 to observe and estimate the torsion state. Formulas 1 to 5 are model formulas input in advance and set in the engine speed observer 113a and the motor speed observer 113b for observing the engine speed and the motor speed.

[0104] [Formula 1]

[0105]

[0106] [Formula 2]

[0107]

[0108] [Formula 3]

[0109]

[0110] [Formula 4]

[0111]

[0112] [Formula 5]

[0113] ω w =α·r·ω w

[0114] Here, various symbols will be defined as follows:

[0115] J e : Engine rotational inertia

[0116] J m : Motor rotation inertia

[0117] k d : Torsional damper stiffness

[0118] k t : Stiffness of the transmission drive system

[0119] ω e : Measured engine speed

[0120] Observed engine speed

[0121] ω m : Measured motor speed

[0122] Observed motor speed

[0123] T e : Engine torque command

[0124] Observed shock absorber torque

[0125] T m : Motor torque command

[0126] Observed output torque

[0127] L d,p ,L t,p : Observer feedback P gain

[0128] L d,i ,L t,i : Observer feedback I gain

[0129] r: current transmission ratio

[0130] α: Wheel speed offset correction factor

[0131] ω w : Measured wheel speed

[0132] ω w *: Equivalent wheel speed

[0133] In formulas 1 to 5, the engine moment of inertia J e , motor moment of inertia J m , torsional damper stiffness k d , transmission drive system stiffness k t , observer feedback P gain L d,p , L t,p , observer feedback I gain L d,i , L t,i The above are setting information that is input in advance and stored in the viewer.

[0134] The engine speed observer 113a can observe the engine speed based on equations 1 and 2: Here, the observed engine speed observed in the previous period and the engine torque command T fed back as an input value by the driving torque command generator 115 e and the measured engine speed ω detected by the engine speed detector 104 e The value of is used as feedback information in Formula 1. In this way, the engine speed is observed The observed engine speed (i.e., the current observed value) remains constant without deviating from the measured engine speed ω e .

[0135] Here, the command T input from the driving torque command generator 115 may be used. e Instead of using the actual engine torque value as input, the engine speed is observed and estimated.

[0136] Here, as desired, the observed engine speed (ie, engine speed observation) may be defined as the difference between the measured engine speed (ie, engine speed measurement) and the measured motor speed (ie, motor speed measurement).

[0137] In addition, as in Equation 2, the engine speed observer 113a uses the measured engine speed ω e The observed engine speed The difference between the two is used as the feedback term for the integration in order to observe the output torque (or the observed damper torque) To improve the observed response, the torsional damper stiffness k is used. d The model of is used as a feedforward term. Here, as can be seen from Equation 2 and Figure 7 As can be seen, the measured motor speed ω can be used m and the measured engine speed ω e .

[0138] Referring to the above formula 1, it can be understood that the engine speed observer 113a uses the output torque (ie, the observed damper torque ) to determine the observed engine speed

[0139] The motor speed observer 113b can observe the motor speed based on equations 3 and 4: In order to observe the current motor speed The motor torque command T is fed back as an input value by the driving torque command generator 115. m , the measured motor speed ω detected by the motor speed detector 105 m , the measured wheel speed ω detected by the wheel speed detector 106 w The observed motor speed observed in the previous period is used as feedback information. In addition, the shock absorber delivered torque is used as input.

[0140] The motor speed observer 113b converts the observed motor speed observed in the previous period into Used as feedback information to observe the motor speed while maintaining the currently observed motor speed Does not deviate from the actual measured motor speed ω m .

[0141] As described above, the motor speed observer 113b converts the observed output torque (ie, the observed damper torque) obtained by the engine speed observer 113a into Used as a shock absorber to transmit torque.

[0142] In addition, instead of using the actual motor torque value as input, the command T generated by the drive torque command generator 115 is used. m The value of is used as input from the motor speed observer 113b to observe and estimate the motor speed

[0143] In addition, as in Formula 4, the measured motor speed ω m The observed motor speed The difference between is used as the feedback term of the integration so that the output torque observed by the motor speed observer 113b (or the observed output torque) is Use the transmission drive system stiffness k t The model of is used as a feed-forward term to improve the observed response. From Equation 4, it can be understood that from the measured wheel speed ω w The equivalent wheel speed ω obtained w *Can be measured with the motor speed ω m Use together.

[0144] Here, the equivalent wheel speed ωw * can be defined as the equivalent speed at the motor by dividing the measured wheel speed ω by the gear ratio corresponding to the current gear w Converted into the speed of the motor.

[0145] Referring to Formula 3, it can be understood that the motor speed observer 113b uses the output torque, (ie, the observed output torque ) to determine the observed motor speed

[0146] Here, the observed motor speed (ie, the motor speed observation value) may be defined as the difference between the measured motor speed (ie, the motor speed observation value) and the equivalent wheel speed, as needed.

[0147] Formula 5 above is used to calculate the equivalent wheel speed ω w * The formula can be used to calculate the current transmission ratio r and the wheel speed offset correction factor α according to the measured wheel speed ω w To calculate ω w *.

[0148] Measured wheel speed ω w It can be obtained based on the driving wheels of the vehicle, or can be obtained by correcting the deviation between the left and right wheels or the deviation between the front and rear wheels.

[0149] For example, the measured wheel speed ω w It may be the average speed of the left wheel speed and the right wheel speed or the average speed of the front wheel speed and the rear wheel speed.

[0150] In addition, the wheel speed used by the torsion observer 113 of the controller 110 may be the equivalent wheel speed ω on the motor. w *, i.e., the wheel speed from the perspective of the electric motor, which is calculated taking into account the electric wheel ratio r after the deviation between the left and right wheels or the deviation between the front and rear wheels.

[0151] That is, as shown in Formula 5, the wheel speed ω detected by the wheel speed detector 105 can be expressed as m Multiply the electric wheel transmission ratio r and the wheel speed offset correction factor α to calculate the equivalent wheel speed ω w *. The equivalent wheel speed ω calculated in this way w *Available for Formula 4.

[0152] Since the electric wheel ratio r reflects the transmission ratio of the transmission, that is, the transmission ratio of the current gear position, in the case of a vehicle equipped with a normal transmission with a fixed number of transmission ratios, the equivalent wheel speed ω w* is the wheel speed converted taking into account the current gear of the transmission and is equal to the motor speed.

[0153] The wheel speed deviation correction factor α is a correction factor for coping with a small change in the actual gear ratio (caused by wear or replacement of tires) and reflecting a small change in the gear ratio.

[0154] The wheel speed offset correction factor α has an initial value of 1. The wheel speed offset correction factor α is obtained by averaging and integrating the difference between the observed motor speed and the equivalent wheel speed over time, starting from an initial value of 1.

[0155] However, any difference obtained during gear shifting when the speed change state of the transmission is within the actual transmission range or obtained during electric wheel slip such as a creeping state of the vehicle will be omitted.

[0156] In addition, the torsion observer 113 of the controller 110 estimates and observes the torsion state of the driving system (ie, the shock absorber and the transmission) based on the observed rotation speed obtained through the calculation process according to Formulas 1 to 5.

[0157] The observed engine speed obtained by the engine speed observer 113a The observed motor speed obtained by the motor speed observer 113b and equivalent wheel speed ω w *To determine the torsional state observations of the drive system.

[0158] Here, the observed torsional state of the shock absorber is given by the observed engine speed and the observed motor speed The torsional state observation of the transmission is determined by the observed motor speed and equivalent wheel speed ω w *Sure.

[0159] The observed values ​​of the torsional state of the shock absorber and the observed values ​​of the torsional state of the transmission include the torsional angular velocity (or torsional speed), the torsional angular acceleration and the torsional angle, respectively. and the observed motor speed The difference between them is the torsional angular velocity in the torsional state observation of the shock absorber.

[0160] In addition, the observed motor speed and the equivalent wheel speed ω w *The difference between is the torsional angular velocity in the torsional state observation value of the transmission.

[0161] In addition, as can be seen from Formulas 1 to 4, not only the torsional angular velocity but also the torsional angular acceleration is observed. The torsional angle can be obtained by integrating the observed torsional angular velocity.

[0162] As described above, the torsional angular velocity, torsional angular acceleration and torsional angle of the drive system (i.e., the shock absorber and the transmission) obtained by the torsional observer 113 are torsional state observation values ​​obtained by observing (or estimating) the torsional state of the drive system using the measured engine speed, the measured motor speed and the measured wheel speed and the drive torque command (including the engine torque command and the motor torque command). These torsional state observation values ​​are input to the second torque command generator 114.

[0163] The second torque command generator 114 sets the sum of the products of the torsional state observation value and the control gain as the feedback torque command.

[0164] That is, the second torque command generator 114 generates a feedback torque command corresponding to the torsional state based on the torsional angular velocity, torsional angular acceleration and torsional angle on the drive system (i.e., the shock absorber and the transmission) by summing the products obtained by multiplying the torsional angular velocity, torsional angular acceleration and torsional angle by corresponding predetermined control gains and setting the sum as the feedback torque command.

[0165] Here, the sum of products obtained by multiplying the torsional angular velocity, the torsional angular acceleration, and the torsional angle on the shock absorber by corresponding control gains is determined as the feedback engine torque command.

[0166] In addition, the sum of products obtained by multiplying the torsional angular velocity, the torsional angular acceleration, and the torsional angle on the transmission by corresponding control gains is determined as a feedback motor torque command.

[0167] The feedback engine torque command and the feedback motor torque command determined by the second torque command generator 114 as described above are input to the driving torque command generator 115. The driving torque command generator 115 receives the feedforward torque command output by the first torque command generator 112 and the feedback torque command output by the second torque command generator 114, and generates a final driving torque command by inputting the feedforward torque command and the feedback torque command therein.

[0168] Here, the drive torque command generator 115 generates an engine torque command which is the sum of a feedforward engine torque command and a feedback engine torque command, and a motor torque command which is the sum of a feedforward motor torque command and a feedback motor torque command.

[0169] That is, a feedforward torque command determined based on the driver's driving input value and a feedback torque command determined based on the torsional state observation value are summed, and the sum is determined as a driving torque command (including an engine torque command and a motor torque command).

[0170] Therefore, the engine torque command finally determined by the driving torque command generator 115 is input to an engine control unit (ECU, not shown), which in turn controls the operation of the engine using the engine torque command.

[0171] In addition, the motor torque command finally determined by the driving torque command generator 115 is input to a motor control unit (MCU, not shown), which in turn controls the operation of the motor using the motor torque command.

[0172] As described above, an embodiment has been described in which the sum of the products obtained by multiplying the torsional angular velocity, torsional angular acceleration and torsional angle on the shock absorber by the corresponding control gains is determined as a feedback engine torque command and the sum of the products obtained by multiplying the torsional angular velocity, torsional angular acceleration and torsional angle on the transmission by the corresponding control gains is determined as a feedback motor torque command.

[0173] This embodiment provides a method of controlling the torsion value observed from the damper and the transmission (i.e., the torsion state observation value) to be used as torque feedback information for the engine and the motor. According to this method, the feedback control input calculated by the torsion of the damper (i.e., the first feedback torque command) is basically applied in the direction of limiting the engine torque, while the feedback control input calculated by the torsion of the transmission (i.e., the second feedback torque command) is applied in the direction of limiting the motor torque.

[0174] In other words, according to the aforementioned embodiment, the drive torque command generator 115 generates a final engine torque command by correcting the feedforward engine torque command generated by the first torque command generator 112 to a degree equal to the first feedback torque command, and generates a final motor torque command by correcting the feedforward motor torque command generated by the second torque command generator 114 to a degree equal to the second feedback torque command.

[0175] According to another embodiment, the driving torque command generator 115 may calculate the final motor torque command by adding all feedback torque commands output by the second torque command generator 114 and the feedforward motor torque command generated and output by the first torque command generator 112 .

[0176] That is, the following are added to the feed-forward motor torque: a feedback torque command obtained by summing the products of the torsional angular velocity, torsional angular acceleration and torsional angle on the shock absorber multiplied by the corresponding control gain, and a feedback torque command obtained by summing the products of the torsional angular velocity, torsional angular acceleration and torque angle on the transmission multiplied by the corresponding control gain.

[0177] Here, the feedforward engine torque generated and output by the first torque command generator 112 is determined as a final engine torque command by the driving torque command generator 115 .

[0178] In addition, according to the present embodiment, the feedback control input (i.e., the feedback torque command) calculated by the torsional value of the shock absorber can be applied in the direction of assisting the motor torque, and the feedback control input (i.e., the feedback torque command) calculated by the torsional value of the transmission can be applied in the direction of limiting the motor torque.

[0179] This method results in the torque values ​​respectively observed (at the shock absorber and the transmission) being used only as feedback for the torque of the electric motor.

[0180] In summary, according to the present embodiment, the drive torque command generator 115 uses the first feedback torque command and the second feedback torque command to correct the feedforward motor torque command generated by the first torque command generator 112, and generates the correction result as the final motor torque command. On the contrary, the final motor torque command is determined as the feedforward motor torque command generated by the first torque command generator 112.

[0181] According to another embodiment, as in the previous embodiment, the respectively observed torsion value is used only as feedback of the motor torque. The feedback torque can be applied within the allowable amount of the motor performance, and the excessive torque can be applied in the direction of limiting the engine torque.

[0182] That is, the drive torque command generator 115 corrects the feedforward motor torque command generated by the first torque command generator 112 using the first feedback torque command and the second feedback torque command, and generates a correction value as the final motor torque command. The final motor torque command is limited so that the final motor torque command is within a preset allowable amount of motor performance. Conversely, the feedforward engine torque command is corrected by an excess amount of the first feedback torque command or an excess amount of the second feedback torque command exceeding the allowable amount. In this way, the corrected command value is determined as the final engine torque command.

[0183] In addition, when a motor other than the drive motor (e.g. Figure 1When the starter motor (MG2) 15) in the embodiment is connected to the engine directly or via a belt, in all cases, the portion corresponding to the engine torque command feedback (ie, the feedback engine torque command) may be a torque command for controlling another motor.

[0184] In addition, when a motor other than the drive motor (e.g. Figure 1 When the starter motor (MG2) 15) in the embodiment is connected to the engine directly or via a belt, in all cases, one of the first feedback torque, the second feedback torque command and a combination thereof may be a compensation torque command for controlling another motor.

[0185] In addition, the compensation torque command can be distributed to multiple motors (e.g., Figure 1 MG1 and MG2) to perform compensation control.

[0186] As described above, according to the embodiments of the present disclosure, the drive torque command generating device and method of the HEV can obtain a quick response of the vehicle in response to the driver's drive input (for example, the driver operating the accelerator pedal). Drive) and at the same time can effectively reduce NVH problems caused by the torsion and clearance of the drive system, even in the case where the drive input causes a significant change in the drive force.

[0187] In addition, according to the embodiments of the present disclosure, in the case of overcoming the NVH problem caused by the torsion and clearance of the drive system, by considering many factors, the difficulty of setting the torque command filter or the torque gradient in a case-specific manner and the excessive processing steps, which are the problems of the prior art solution using the rate limiter or the filter, can be overcome. In addition, since the torque command suitable for a specific time point can be generated in real time, the improvement of efficiency can be expected.

[0188] In particular, according to an embodiment of the present disclosure, a drive torque command can be generated by pre-observing the result of the clearance or vibration of the drive system according to the change in torque before the torque is actually generated, thereby effectively reducing NVH problems, even when there is a unique control delay time in the engine or motor.

[0189] Although exemplary embodiments of the present disclosure have been described for illustrative purposes, the scope of the present disclosure is not limited thereto. It should be understood that various modifications and improvements will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure as disclosed in the appended claims.

Claims

1. A driving torque command generating device for a hybrid electric vehicle, the device include: a driving input detector for detecting a driving input value of a driver, the driving input value including a pedal input value in response to manipulation of an accelerator pedal; An engine speed detector for detecting an engine speed of a vehicle engine; a motor speed detector for detecting a motor speed of a motor used as a driving source of the vehicle; A wheel speed detector, used to detect the wheel speed of the vehicle wheel; and a controller for obtaining a torsional state observation value together using the measured engine speed, the measured motor speed, and the measured wheel speed detected by the engine speed detector, the motor speed detector, and the wheel speed detector, respectively, and the motor torque command generated in a previous period, and generating an engine torque command and a motor torque command of a drive torque command based on the drive input value input by the drive input detector and the torsional state observation value; Wherein, the controller comprises: a target torque generator for generating a target engine torque and a target motor torque for controlling the engine and the motor according to the drive input value inputted from the drive input detector; a first torque command generator for generating a feedforward engine torque command and a feedforward motor torque command through the target engine torque and the target motor torque using a torque gradient determined based on vehicle state information; a torsional observer for generating the torsional state observation value by observing the torsional state of the vehicle drive system based on the measured engine speed, the measured motor speed and the measured wheel speed together with the motor torque command generated by the drive torque command generator in the previous period; a second torque command generator for generating a feedback torque command for reducing the torsion of the vehicle drive system based on the torsion state observation value generated by the torsion observer; and The driving torque command generator is used to generate the engine torque command and the motor torque command by using the feedforward engine torque command and the feedforward motor torque command generated by the first torque command generator and the feedback torque command generated by the second torque command generator.

2. The device according to claim 1, in, The drive torque command generator generates the engine torque command and the motor torque command by correcting the feedforward engine torque command and the feedforward motor torque command using the feedback torque command that reduces the twist of the vehicle drive system.

3. The device according to claim 1, in, The torsion observer comprises: an engine speed observer for observing the engine speed based on the measured engine speed, the observed engine speed observed in the previous period and received as feedback information, and the engine torque command for the previous period generated by the drive torque command generator; and a motor speed observer for observing the motor speed based on the measured motor speed, the observed motor speed observed in the previous period and received as feedback information, and the motor torque command for the previous period generated by the drive torque command generator, The torsional state observation value is determined by the observed engine speed observed by the engine speed observer and the observed motor speed observed by the motor speed observer.

4. The device according to claim 3, in, The torsional state observations in the vehicle drive system include: a torsional state observation value on the shock absorber obtained by observing the torsional state of the shock absorber between the engine and the motor; and The torsional state observation value on the transmission is obtained by observing the torsional state of the transmission located on the output side of the motor.

5. The device according to claim 4, in, The torsional state observations on the shock absorber include torsional angular velocity, torsional angular acceleration and torsional angle on the shock absorber, and The torsional state observations on the transmission include torsional angular velocity, torsional angular acceleration and torsional angle on the transmission.

6. The device according to claim 5, in, determining the torsional angular velocity at the shock absorber by the difference between the observed engine speed and the observed motor speed, and The torsion angle at the shock absorber is determined by integrating the torsion angular velocity at the shock absorber.

7. The device according to claim 5, in, The torsional angular velocity on the transmission is determined as the difference between the observed motor speed and the equivalent wheel speed, the torsional angle on the transmission is calculated by integrating the torsional angular velocity on the transmission, and the equivalent wheel speed is obtained by converting the measured wheel speed into the speed on the motor using the gear ratio corresponding to the current gear.

8. The device according to claim 5, in, The second torque command generator generates a first feedback torque command, which is the sum of the products of the torsional angular velocity, the torsional angular acceleration and the torsional angle on the shock absorber multiplied by the corresponding predetermined control gain, and the torsional angular velocity, the torsional angular acceleration and the torsional angle on the shock absorber are the torsional state observation values ​​on the shock absorber; and the second torque command generator generates a second feedback torque command, which is the sum of the products of the torsional angular velocity, the torsional angular acceleration and the torsional angle on the transmission multiplied by the corresponding predetermined control gain, and the torsional angular velocity, the torsional angular acceleration and the torsional angle on the transmission are the torsional state observation values ​​on the transmission.

9. The device according to claim 8, in, The drive torque command generator generates a final engine torque command by correcting the feedforward engine torque command generated by the first torque command generator using the first feedback torque command, and generates a final motor torque command by correcting the feedforward motor torque command generated by the second torque command generator using the second feedback torque command.

10. The device according to claim 8, in, The drive torque command generator generates a final motor torque command by correcting the feedforward motor torque command generated by the first torque command generator using the first feedback torque command and the second feedback torque command, and determines the feedforward engine torque command generated by the first torque command generator as a final engine torque command.

11. The device according to claim 8, in, The drive torque command generator generates a final motor torque command by correcting the feedforward motor torque command generated by the first torque command generator using the first feedback torque command and the second feedback torque command, Wherein, the final motor torque command is limited so that the final motor torque command is within an allowable amount of a preset motor performance, and the feedforward engine torque command is corrected by the first feedback torque command or the second feedback torque command that exceeds the allowable amount, so that the corrected command value is determined as the final engine torque command.

12. A method for generating a driving torque command for a hybrid electric vehicle, the method The following steps are involved: detecting, by a driving input detector, a driving input value of a driver, the driving input value of the driver including a pedal input value in response to manipulation of an accelerator pedal; detecting an engine speed of a vehicle engine by an engine speed detector; detecting, by a motor speed detector, a motor speed of a motor serving as a driving source of the vehicle; detecting the wheel speed of the wheels of the vehicle by a wheel speed detector; and obtaining, by a controller, a torsional state observation value using a measured engine speed, a measured motor speed, and a measured wheel speed detected by the engine speed detector, the motor speed detector, and the wheel speed detector, respectively, and a motor torque command generated in a previous period; and generating, by the controller, an engine torque command and a motor torque command of a drive torque command based on the drive input value input by the drive input detector and the torsional state observation value; The process of generating the engine torque command and the motor torque command by the controller includes: generating a target engine torque and a target motor torque by the drive input value inputted from the drive input detector, and controlling the engine and the motor by the target engine torque and the target motor torque; generating a feedforward engine torque command and a feedforward motor torque command through the target engine torque and the target motor torque using a torque gradient determined based on vehicle state information; generating a feedback torque command to reduce torsion of the vehicle drive system based on the torsional state observable; and The engine torque command and the motor torque command are generated by the feedforward engine torque command and the feedforward motor torque command and the feedback torque command.

13. The method according to claim 12, in, The controller generates the engine torque command and the motor torque command by correcting the feed-forward engine torque command and the feed-forward motor torque command using the feedback torque command that reduces twist of the vehicle drive system.

14. The method according to claim 12, in, The process of obtaining the torsional state observation value by the controller includes: observing the engine speed by the engine speed observer based on the measured engine speed, an observed engine speed observed during the previous period and received as feedback information, and an engine torque command during the previous period; observing, by the motor speed observer, the motor speed based on the measured motor speed, the observed motor speed observed in the previous period and received as feedback information, and the motor torque command for the previous period; and The torsional state observation value is determined by the observed engine speed observed by the engine speed observer and the observed motor speed observed by the motor speed observer.

15. The method according to claim 14, in, The torsional state observations in the vehicle drive system include: a torsional state observation value on the shock absorber obtained by observing the torsional state of the shock absorber between the engine and the motor; and The torsional state observation value on the transmission is obtained by observing the torsional state of the transmission located on the output side of the motor.

16. The method according to claim 15, in, The torsional state observation values ​​on the shock absorber include torsional angular velocity, torsional angular acceleration and torsional angle on the shock absorber; and The torsional state observations on the transmission include torsional angular velocity, torsional angular acceleration and torsional angle on the transmission.

17. The method according to claim 16, in, determining the torsional angular velocity at the shock absorber by the difference between the observed engine speed and the observed motor speed, and The torsion angle at the shock absorber is determined by integrating the torsion angular velocity at the shock absorber.

18. The method according to claim 16, in, The torsional angular velocity on the transmission is determined as the difference between the observed motor speed and the equivalent wheel speed, the torsional angle on the transmission is calculated by integrating the torsional angular velocity on the transmission, and the equivalent wheel speed is obtained by converting the measured wheel speed into the speed on the motor using the gear ratio corresponding to the current gear.

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