Hybrid electric vehicle and vibration control method thereof

Abstract

The invention provides a hybrid electric vehicle and a vibration control method thereof. The vibration control method of the hybrid electric vehicle includes: receiving rotor angle information of a motor generated based on information detected by a resolver; receiving first engine rotation angle information of the engine generated based on information detected by the cam angle sensor or the crankshaft angle sensor; generating an engine rotation angle candidate based on the rotor angle information; and identifying a second engine rotation angle based on the engine rotation angle candidate and the first engine rotation angle information.

Description

Technical Field

[0001] The present disclosure relates to a hybrid electric vehicle, and more particularly to a hybrid electric vehicle and a vibration control method thereof. Background Art

[0002] As an alternative to engine vehicles, environmentally friendly vehicles such as pure electric vehicles, hybrid electric vehicles, or fuel cell electric vehicles are called motor-driven vehicles. This is because environmentally friendly vehicles use electric motors as a driving source for driving the vehicle. Among such vehicles, hybrid electric vehicles include both an engine and an electric motor, so it is necessary to detect the rotation angles of the engine and the electric motor for each driving control.

[0003] In this case, in order to detect the absolute angular position of the rotor of the motor, a resolver is used as a position sensor. The resolver can be used as a position sensor for driving motors in fields that require high performance and high precision driving like electric vehicles because it has higher mechanical strength and durability than an encoder.

[0004] In the case of an engine, if the rotation angle is not detected, it is impossible to measure the position of the crankshaft (for example, the top dead center). Therefore, there is a problem that the fuel injection amount, injection timing, and ignition timing of the engine cannot be accurately determined.

[0005] In this regard, a technology has been designed that replaces the crankshaft angle sensor of the engine with a rotary transformer of the motor to generate virtual crankshaft angle sensor information and control the engine based on the virtual crankshaft angle sensor information. However, there is a disadvantage that this conventional technology is not suitable for most motors with multiple pole pairs because the mechanical matching between the rotary transformer signal and the position of multiple crankshaft angles is not considered. In addition, because the position of the four-stroke engine has a rotation angle ranging from 0 degrees to 720 degrees, there are disadvantages in converting the mechanical angle of the rotary transformer into the crankshaft angle of the engine. In addition, the signal delay that occurs when information is exchanged between control units through controller area network (CAN) communication is not considered. Summary of the invention

[0006] Thus, in this technical field, it is desirable to apply a solution to electric motors with a large number of pole pairs. Furthermore, it is desirable to take into account the conversion of mechanical angle to crankshaft angle and the signal delay in CAN communication to accurately measure the angular position of the engine.

[0007] The present disclosure is proposed to solve the above-mentioned problems. An aspect of the present disclosure provides a hybrid electric vehicle and an engine angular position estimation method thereof, which are applicable to a motor having a large number of pole pairs.

[0008] Other aspects of the present disclosure are to provide a hybrid electric vehicle and an engine angular position estimation method thereof, wherein the mechanical angle of a rotary transformer is converted into an engine crankshaft angle and signal delay occurring when information is exchanged between control units through a controller area network (CAN) communication is taken into account.

[0009] Yet another aspect of the present disclosure provides a hybrid electric vehicle in which an angular position of an engine is accurately estimated, and a motor accurately compensates for torque of the engine based on the estimated angular position of the engine.

[0010] The technical problems to be solved by the present disclosure are not limited to the above technical problems. A person skilled in the art in the field to which the present disclosure belongs can more clearly understand other technical problems not mentioned from the following description.

[0011] According to an embodiment of the present disclosure, a vibration control method for a hybrid electric vehicle is provided. The method includes receiving rotor angle information of a motor of a vehicle generated based on information detected by a rotary transformer, and includes receiving first engine rotation angle information generated based on information detected by a cam angle sensor or a crankshaft angle sensor. The method also includes generating an engine rotation angle candidate based on the rotor angle information, and identifying a second engine rotation angle based on the engine rotation angle candidate and the first engine rotation angle information.

[0012] In this case, the number of engine rotation angle candidates may be based on the number of magnetic poles of a rotor magnet of a motor of the hybrid electric vehicle.

[0013] In this case, identifying the second engine rotation angle may include identifying a first index and a second index based on the engine rotation angle candidate and the first engine rotation angle information. In addition, identifying the second engine rotation angle may include identifying the second engine rotation angle based on the first index and the second index.

[0014] In this case, the vibration control method may also include the following steps: storing the first index and the second index in a memory; and when the engine of the hybrid electric vehicle is started next time after the engine is shut down, estimating the second engine rotation angle again based on the stored first index and the second index and the rotor angle information of the electric motor.

[0015] In this case, the first index and the second index may include a value for indicating one of the engine rotation angle candidates.

[0016] In this case, the vibration control method may further include controlling an engine of the hybrid electric vehicle based on the second engine rotation angle to control the hybrid electric vehicle to travel.

[0017] According to an embodiment of the present disclosure, a hybrid electric vehicle is provided. The vehicle includes a rotor angle operation unit and an engine rotation angle operation unit, the rotor angle operation unit is configured to generate rotor angle information of an electric motor of the vehicle based on information detected by a rotary transformer, and the engine rotation angle operation unit is configured to generate first engine rotation angle information based on information detected by a cam angle sensor or a crankshaft angle sensor. The vehicle further includes a synchronization operation unit configured to generate an engine rotation angle candidate based on the rotor angle information, and identify a second engine rotation angle based on the engine rotation angle candidate and the first engine rotation angle information.

[0018] In this case, the number of engine rotation angle candidates may be based on the number of magnetic poles of a rotor magnet of a motor of the hybrid electric vehicle.

[0019] In this case, the synchronization operation unit may identify the first index and the second index based on the engine rotation angle candidate and the first engine rotation angle information, and may identify the second engine rotation angle based on the first index and the second index.

[0020] In this case, the synchronization operation unit may store the first index and the second index in the memory. In addition, the synchronization operation unit may estimate the second engine rotation angle again based on the stored first index and the second index and the rotor angle information of the motor when the engine of the hybrid electric vehicle is started next time after the engine is turned off.

[0021] In this case, the first index and the second index may include a value for indicating one of the engine rotation angle candidates.

[0022] In this case, the hybrid control unit may control the hybrid electric vehicle to travel by controlling the engine of the hybrid electric vehicle based on the second engine rotation angle.

[0023] According to the present disclosure, the angular position of the engine is estimated based on the resolver signal of the motor, wherein the resolver signal has high resolution and is strong. As a result, it is achieved that the main control of the engine is performed at high resolution at accurate timing.

[0024] In addition, the crank angle of the engine is processed in the same manner as previously performed to perform internal control of the engine. The motor synchronizes the angular position of the motor with the angular position of the engine, thereby smoothly performing vibration control by offsetting changes in torque and speed of the engine through the motor.

[0025] In addition, the control of the engine is performed based on the existing engine crankshaft angle signal processing, the control of the motor is performed based on the existing resolver-based motor position signal, and the hybrid control unit that distributes the torque of the engine and the motor distributes the instantaneous torque in consideration of the phases of the engine and the motor. Therefore, the instantaneous torque of the motor can offset the change of the instantaneous torque of the engine, thereby smoothly performing vibration control that controls the change of the torque and speed of the engine at a low revolution per minute (RPM) through the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A configuration of a power train in a hybrid electric vehicle according to an embodiment of the present disclosure is shown.

[0027] Figure 2 A configuration of a control system in a hybrid electric vehicle according to an embodiment of the present disclosure is shown.

[0028] Figure 3 is a block diagram of an engine angular position estimation system according to an embodiment of the present disclosure.

[0029] Figure 4 yes Figure 3 Block diagram of the synchronous computing unit of the system.

[0030] Figure 5A The electrical angle of the motor rotor is shown.

[0031] Figure 5B Shows the corresponding Figure 5A The mechanical angle of the electrical angle.

[0032] Fig. 6A The mechanical angle of the motor rotor is shown.

[0033] Figure 6B Shows the corresponding Fig. 6A The mechanical angle of the motor rotor is the engine crankshaft angle.

[0034] Figure 7 It is shown that the synchronization operation unit according to the embodiment of the present disclosure estimates the first index and the second index and the second engine rotation angle.

[0035] Figure 8 is a flow chart describing an engine angular position estimation method according to an embodiment of the present disclosure.

[0036] Fig. 9 is a block diagram of an engine angular position estimation system according to another embodiment of the present disclosure.

[0037] Fig.10 is a block diagram of an engine angular position estimation system according to yet another embodiment of the present disclosure.

[0038] Fig.11A An example of a target wheel that may be used in a camshaft of an engine according to an embodiment of the present disclosure is shown.

[0039] Fig. 11B Another example of a target wheel that may be used in a camshaft of an engine according to an embodiment of the present disclosure is shown.

[0040] Fig.12 is a block diagram of an engine angular position estimation system according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings, wherein even if the same or similar parts are shown in different drawings, they are represented by the same reference numerals. In addition, redundant descriptions thereof have been omitted. Suffixes such as "module" and "unit" placed after the components in the following description are used for convenience of description and do not have meanings or functions that distinguish one from another. In addition, in describing the embodiments of the present disclosure, detailed descriptions of related technologies are omitted in cases where the subject matter of the embodiments of the present disclosure is rather unclear. In addition, the accompanying drawings are provided only to enhance the understanding of the embodiments of the present disclosure and are not intended to limit the technical concept of the present disclosure. Therefore, it should be understood that the accompanying drawings include all modifications, equivalents, and substitutions within the scope and spirit of the present disclosure.

[0042] Terms such as "first" and "second" may be used to describe various components, but these components should not be limited by the above terms. In addition, the above terms are only used to distinguish one component from another component.

[0043] When describing that one component is "connected" or "joined" to another component, it should be understood that the one component may be directly connected or joined to the other component, but there may be other components in between. However, when a component is described as being "directly connected" or "directly coupled" to another component, it should be understood that there may not be other components between the one component and the other component.

[0044] Unless the context clearly indicates otherwise, singular forms also include plural forms.

[0045] In the present disclosure, it should be understood that terms such as "include", "comprise", or "have" indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the embodiments. These terms do not exclude the possibility of the prior existence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0046] Furthermore, terms such as "unit" or "control unit" forming part of the name of a motor control unit (MCU), a hybrid control unit (HCU), etc. are merely terms widely used in the naming of controllers for controlling specific functions of a vehicle, and should not be interpreted as meaning a general functional unit. For example, each control unit may include a communication device for communicating with other control units or sensors in order to control its own functions, a memory for storing an operating system, logic commands and input / output information, and one or more processors for performing determinations, calculations, decisions, etc. necessary for controlling the functions for which it is responsible.

[0047] When a controller, component, device, element, part, unit, module, etc. of the present disclosure is described as having a purpose or performing an operation, function, etc., the controller, component, device, element, part, unit, or module should be considered herein as "configured to" meet the purpose or perform the operation or function. Each controller, component, device, element, part, unit, module, etc. may embody a processor and a memory (such as a non-transitory computer-readable medium) alone or be included together with the processor and the memory as part of the device.

[0048] Before describing a method of controlling a hybrid electric vehicle according to an embodiment of the present disclosure, a structure and a control system for a hybrid electric vehicle applicable to the embodiment are first described.

[0049] Figure 1 A configuration of a power train in a hybrid electric vehicle according to an embodiment of the present disclosure is shown.

[0050] refer to Figure 1 , the powertrain of the hybrid electric vehicle adopts a parallel hybrid system, in which two motors (a first motor 120 and a second motor 140) and an engine clutch 130 are installed between an engine (internal combustion engine, ICE) 110 and a transmission 150. This parallel hybrid system can also be called a transmission mounted electric drive (TMED) hybrid system because the motor is always connected to the input end of the transmission 150.

[0051] The first motor 120 is placed between the engine 110 and a first end of the engine clutch 130. An engine shaft of the engine 110 and a first motor shaft of the first motor 120 are directly connected to each other and always rotate together.

[0052] The second motor shaft of the second motor 140 has a first end connected to the second end of the engine clutch 130 and a second end connected to the input end of the transmission 150 .

[0053] The second motor 140 may have a greater power output than the first motor 120 and may be used as a drive motor. In addition, when the engine 110 is started, the first motor 120 may be used as a starter motor for cranking the engine 110, when the engine is turned off, the first motor 120 may recover the rotational energy of the engine 110 by generating electricity, and when the engine 110 is running, the first motor 120 may generate electricity by the power of the engine 110.

[0054] Including Figure 1 In the hybrid electric vehicle (HEV) of the powertrain shown, when the driver depresses the accelerator pedal after starting the vehicle (e.g., HEV preparation), the second motor 140 is first driven with power from a battery (not shown) when the engine clutch 130 is opened. The power from the second motor 140 is then transmitted to the wheels of the vehicle via the transmission 150 and the final drive (FD) 160, thereby moving the wheels (i.e., electric vehicle (EV) mode). As the vehicle gradually accelerates and greater driving force is required, the first motor 120 can be operated to crank the engine 110.

[0055] After the engine 110 is started, when the speed difference between the engine 110 and the second motor 140 falls within a specific range, the engine clutch 130 is engaged, so that the engine 110 and the second motor 140 rotate together (i.e., switching from EV mode to HEV mode). Then, the output of the second motor 140 is reduced and the output of the engine 110 is increased by torque blending processing, thereby meeting the torque required by the driver. In HEV mode, the engine 110 can meet the required torque, and the difference between the engine torque and the required torque can be compensated by at least one of the first motor 120 and the second motor 140. For example, when the engine 110 outputs a torque higher than the required torque in consideration of the efficiency of the engine 110, the first motor 120 or the second motor 140 can perform as much power generation as the remaining engine torque. On the other hand, when the engine torque is lower than the required torque, at least one of the first motor 120 and the second motor 140 can output torque to compensate for the deficiency.

[0056] When the preset engine shutoff condition is satisfied due to the deceleration of the vehicle, etc., the engine clutch 130 is opened and the engine 110 is stopped (i.e., the HEV mode is switched to the EV mode). During deceleration, the battery is charged using the driving force of the wheels through the second motor 140, which is called brake energy recovery or regenerative braking.

[0057] Typically, the transmission 150 may include a step-variable transmission or a multi-plate clutch, such as a dual clutch transmission (DCT).

[0058] Figure 2 A configuration of a control system in a hybrid electric vehicle according to an embodiment of the present disclosure is shown.

[0059] Reference Figure 2 In a hybrid electric vehicle to which an embodiment of the present disclosure may be applied, the engine 110 may be controlled by an engine control unit 210 , the torques of the first motor 120 and the second motor 140 may each be controlled by a motor control unit (MCU) 220 , and the engine clutch 130 may be controlled by a clutch control unit 230 .

[0060] The engine control unit 210 is also referred to as an engine management system (EMS). The engine control unit 210 may recognize a fuel injection amount, an injection timing, and an ignition timing of the engine 110 using virtual angle sensor information of the engine generated by the motor control unit 220.

[0061] Furthermore, the transmission 150 is controlled by a transmission control unit 250 .

[0062] The motor control unit 220 may control a gate drive unit (not shown) using a pulse width modulation (PWM) control signal based on the motor angle, phase voltage, phase current, required torque, etc. of each of the first motor 120 and the second motor 140. The gate drive unit may control an inverter (not shown) for driving each of the first motor 120 and the second motor 140 based on the control signal. The motor control unit 220 may obtain information about the motor angle (or rotation angle) through a rotary transformer (not shown) provided in each of the first motor 120 and the second motor 140.

[0063] Each control unit is connected to its higher-level control unit, the hybrid control unit (HCU) 240, which controls the entire powertrain, including the mode switching process. The hybrid control unit 240 can provide the information necessary to change the drive mode, shift gears and / or control the engine clutch when the engine is stopped. The hybrid control unit 240 can also perform operations based on control signals.

[0064] For example, the hybrid control unit 240 identifies whether to switch between EV-HEV modes or CD-CS modes (in the case of PHEV) based on the operating state of the vehicle. To this end, the hybrid control unit 240 determines the timing of opening the engine clutch 130 and performs hydraulic control at the timing. In addition, the hybrid control unit 240 identifies the state (locked, slipped, open, etc.) of the engine clutch 130 and controls the timing to stop the fuel injection of the engine 110. In addition, the hybrid control unit 240 can transmit the torque command for controlling the torque of the first motor 120 to the motor control unit 220 to control the engine to stop, thereby controlling the rotational energy recovery of the engine. In addition, the hybrid control unit 240 can identify the state of each drive source (engine 110, first motor 120 and second motor 140) to meet the required torque. In addition, the hybrid control unit 240 can identify the required driving force shared among the drive sources (engine 110, first motor 120 and second motor 140) based on the identified state, thereby transmitting the torque command to the control unit that controls the drive source.

[0065] It should be clear to those skilled in the art that the aforementioned connections between these control units and the aforementioned functions / divisions of these control units are merely exemplary and are not limited to their nomenclature. For example, the hybrid control unit 240 may be replaced by any one of the other control units, or its functions may be provided in a distributed manner by two or more of the other control units.

[0066] Figure 1 and Figure 2 The aforementioned configuration shown in is merely an example of a hybrid electric vehicle, and the hybrid electric vehicle applicable to the embodiment is not limited to this structure. Figure 1 It is assumed that the first motor 120 and the engine 110 are directly connected to each other. However, the first motor 120 and the engine 110 may be implemented to be connected using a predetermined connection device such as a pulley and a belt.

[0067] Figure 3 is a block diagram of an engine angular position estimation system according to an embodiment of the present disclosure.

[0068] The engine angular position estimation system according to the embodiment may be a hybrid electric vehicle. In addition, at least one component constituting the engine angular position estimation system according to the embodiment may be implemented in each control unit of the hybrid electric vehicle.

[0069] Reference Figure 3According to the embodiment, the engine angular position estimation system may include an engine 310, a first motor 320, a second motor 330, a transmission 340, an engine rotation angle calculation unit 350, a first rotor angle calculation unit 360, a second rotor angle calculation unit 370, a transmission control unit 380 and a synchronization calculation unit 390.

[0070] The engine 310 includes a cam angle sensor 311 for detecting a cam angle and a crank angle sensor 313 for detecting a crank angle.

[0071] The cam angle of the engine detected by the cam angle sensor 311 and the crank angle of the engine detected by the crank angle sensor 313 are transmitted to the sensor-based engine rotation angle calculation unit 350 .

[0072] The first motor 320 and the second motor 330 include a first resolver 321 and a second resolver 331 for measuring resolver angles, respectively.

[0073] The transmission 340 is controlled by a transmission control unit 380 .

[0074] The sensor-based engine rotation angle calculation unit 350 determines the rotation angle of the engine based on the cam angle of the engine detected by the cam angle sensor 311 and the crank angle of the engine detected by the crank angle sensor 313 .

[0075] In this case, the sensor-based engine rotation angle calculation unit 350 may be an engine control unit (ECU) of the vehicle.

[0076] In this case, the rotation angle of the engine recognized by the sensor-based engine rotation angle calculation unit 350 refers to the value used to finally recognize the rotation angle of the engine by the synchronization calculation unit 390. In this specification, the rotation angle of the engine recognized by the sensor-based engine rotation angle calculation unit 350 is defined as a first engine rotation angle. The rotation angle of the engine finally recognized by the synchronization calculation unit 390 is defined as a second engine rotation angle.

[0077] The first rotor operation unit 360 and the second rotor operation unit 370 identify the rotor angles of the first motor 320 and the second motor 330 based on the information about the rotor positions of the first motor 320 and the second motor 330 received from the first rotary transformer 321 and the second rotary transformer 322, respectively. As described above, the first motor 320 and the second motor 330 include the first rotary transformer 321 and the second rotary transformer 331, respectively.

[0078] In this case, the first rotor angle calculation unit 360 and the second rotor angle calculation unit 370 may be a first motor control unit (MCU) and a second motor control unit (MCU) of the vehicle, respectively.

[0079] The synchronization operation unit 390 receives rotor angle information about the first motor 320 from the first rotor angle operation unit 360, receives the first engine rotation angle from the sensor-based engine rotation angle operation unit 350, and identifies the second engine rotation angle based on the received information.

[0080] In this case, the synchronization operation unit 390 may be a hybrid control unit (HCU) of the vehicle.

[0081] Generally, the electrical angle θ of the resolver measured by the first resolver 321 of the first motor 320 directly connected to the engine 310 is known. e With mechanical angle θ m The relationship between θ e = number of pole pairs * θ m However, in reality, one electrical angle θ of the resolver e Matching multiple mechanical angles θ of the crankshaft with the same number of pole pairs m .

[0082] Therefore, an electrical angle θ of the resolver e Matching mechanical angle θ m It can be obtained by the following equation 1.

[0083] [Equation 1]

[0084] θ m =θ e / Number of pole pairs + 360 / Number of pole pairs * N (where N = 0, 1 – ..., number of pole pairs - 1)

[0085] In Equation 1, θ m represents the mechanical angle, and θ e Indicates the electrical angle of the resolver. In addition, the pole pair number indicates the number of magnetic pole pairs of the motor rotor.

[0086] For example, when the electrical angle θ of the resolver eWhen it is 40° and the number of pole pairs is 4, by substituting 0 into N in equation 1, the mechanical angle may be (40 / 4+360 / 4*0)=10. The mechanical angle may also be (40 / 4+360 / 4*1)=100 by substituting 1 into N, (40 / 4+360 / 4*2)=190 by substituting 2 into N, and (40 / 4+360 / 4*3)=280 by substituting 3 into N. The engine rotation angle has a range of 720 degrees. In addition, since the range of the engine rotation angle is as high as 720 degrees, not only mechanical angles 10, 100, 190, and 280, but also angles 370, 460, 550, and 640 degrees obtained by adding 360 degrees to these angles 10, 100, 190, and 280 degrees, respectively, may also be candidates for the engine rotation angle. In other words, the number of mechanical angles that can be estimated (i.e., matched) from one electrical angle of the resolver is as many as the number of pole pairs. The motor's rotation angle is as many as the number of poles of the motor's rotor magnet, which is twice the number of pole pairs. Therefore, the actual rotation angle position of the motor needs to be identified.

[0087] Specifically, Figure 3 As shown, in a system structure including a low-level control unit (such as an engine rotation angle operation unit 350, a motor control unit (360 and 370), and a high-level hybrid control unit (390), a controller area network (CAN) communication is used to transmit and receive information between the high-level control unit (390) and the low-level control unit (350, 360, and 370) that directly obtains the crankshaft angle sensor signal and the resolver signal. In addition, when sending and receiving information between the high-level control unit (390) and the low-level control unit (350, 360, and 370), communication delay may occur. Therefore, it is necessary to synchronize the engine position signal and the motor position signal in consideration of the communication delay.

[0088] Next, a method of estimating the rotation angle of the engine in consideration of the communication delay is described.

[0089] Figure 4 yes Figure 3 Block diagram of the synchronization operation unit 390 in .

[0090] See also Figure 4 The synchronization operation unit 390 includes a rotor angle acquirer 410 , a first engine rotation angle acquirer 430 , an engine rotation angle candidate generator 450 and a second engine rotation angle identifier 470 .

[0091] The rotor angle acquirer 410 acquires the electrical angle θ of the rotary transformer of the first motor 320 directly connected to the engine 310. e .

[0092] The first engine rotation angle acquirer 430 acquires information on the first engine rotation angle (Cacan) from the sensor-based engine rotation angle calculation unit 350 .

[0093] In this case, the first engine rotation angle refers to the rotation angle of the engine recognized by the cam angle sensor 311 or the crank angle sensor 313. However, the first engine rotation angle (Cacan) received by the sensor-based engine rotation angle calculation unit 350 has a time delay α due to the characteristics of CAN communication. Therefore, the second engine rotation angle identifier 470 (described below) obtains the engine rotation angle without time delay.

[0094] The engine rotation angle candidate generator 450 generates an electric angle θ of the resolver obtained by the rotor angle obtainer 410 based on the electric angle θ of the resolver. e Generate engine rotation angle (CA) candidates.

[0095] When the above equation 1 is compared with a resolver electrical angle θ e Matching crankshaft mechanical angle θ m When expressed as the number of magnetic poles P of the motor rotor, which is twice the number of pole pairs, it is shown as the following Equation 2.

[0096] [Equation 2]

[0097] θ m ={θ|(θ e +360*N) / (P / 2)}, (where N=0, 1, ..., P / 2-1)

[0098] In the above equation 2, θ m Represents the mechanical angle of the crankshaft, θ e represents the electrical angle of the resolver, and P represents the number of poles of the motor rotor magnet.

[0099] Figure 5A shows the electrical angle of the motor rotor, and Figure 5B Shows the corresponding Figure 5A The electrical angle is the mechanical angle. In this case, Figure 5A The electrical angle of a motor having a pole pair number of 4 is shown. Figure 5B The corresponding mechanical angles are shown to match the electrical angles. Figure 5A and Figure 5B , because the number of electrical angles of one motor rotor is as many as the number of pole pairs, an additional operation is required to select one of the electrical angles in order to estimate the mechanical angle that matches the electrical angle of the actual motor rotor.

[0100] The rotation angle of the engine is referred to as the crankshaft angle (CA). Fig. 6Aand Figure 6B , CA is within the range of two rotations (0 to 720 degrees). Therefore, two CAs match one mechanical angle of the crankshaft.

[0101] That is, the candidate CA and the electrical angle θ of the motor resolver e The relationship is shown in the following formula 3.

[0102] [Equation 3]

[0103] CA candidate = {θ|(θ e +360*N) / (P / 2), (θ e +360*N) / (P / 2)+360},

[0104] (where N = 0, 1, ..., P / 2-1)

[0105] In Equation 3, the candidate CA represents the candidate of the rotation angle of the engine, θ e represents the electrical angle of the resolver, and P represents the number of poles of the motor rotor magnet. Referring to Equation 3, one electrical angle θ of the resolver e It can be matched with P candidates of the engine rotation angle (ie, P candidates of CA).

[0106] In this case, the candidates of CA generated by the engine rotation angle candidate generator 450 may be represented as a (P / 2)×2 matrix.

[0107] The second engine rotation angle identifier 470 identifies the second engine rotation angle by comparing the plurality of CAs generated by the engine rotation angle candidate generator 450 with the first engine rotation angle (Cacan) acquired by the first engine rotation angle acquirer 430 .

[0108] Since the first engine rotation angle (Cacan) acquired by the first engine rotation angle acquirer 430 has a time delay α due to the characteristics of CAN communication, the second engine rotation angle may be selected as a value having the smallest difference with the first engine rotation angle (Cacan) among the plurality of CA candidates selected as a result of Equation 3.

[0109] Therefore, when the first engine rotation angle (Cacan) is CA plus α (ie, time delay), and the interval between the candidates for CA identified in Equation 3 is greater than α, the second engine rotation angle CA can be obtained by the following Equation 4.

[0110] [Equation 4]

[0111] CA=min[abs{CAcan–(θ|(θ e +360*N) / (P / 2), (θe +360*N) /

[0112] (P / 2)+360)}], (where N=0, 1, ..., P / 2-1)

[0113] In Equation 4, CA represents the rotation angle of the engine, θ e represents the electrical angle of the rotary transformer, and P represents the number of poles of the motor rotor magnet. Referring to Equation 4, a rotation angle having a minimum difference with the first engine rotation angle (Cacan) among the candidates of the engine rotation angle may be selected as the final engine rotation angle (ie, the second engine rotation angle).

[0114] For example, when the engine rotates at 1000 revolutions per minute (RPM) and the delay of CAN communication between the engine control unit 210 and the hybrid control unit 240 is 1 millisecond, an angle error of 360*1000 / 60*0.001=about 6 degrees occurs due to the time delay. When the motor has 8 poles, the difference in the rotation angle between the CA candidates is 720 / 8=90 degrees, thereby satisfying the prerequisite for applying equation 4. When the second engine rotation angle CA is obtained by equation 4, a first index and a second index can be generated based on the obtained value and stored in a memory. The first index (index1) corresponds to a value of N that matches the value of CA obtained in equation 4. The second index (index2) indicates whether the two candidates for CA corresponding to a value of N have a rotation angle less than or greater than 360 degrees, that is, whether the rotation angle is the value plus 360 degrees. For example, the second index may have a value of 1 or 2. For example, when the motor is an 8-pole motor, the electrical angle θ corresponding to the resolver is e The candidates for CA may be represented by a 4*2 matrix, and the first and second indexes may indicate the second engine rotation angle CA finally recognized by the second engine rotation angle identifier 470 among the candidates for CA.

[0115] The second engine rotation angle identifier 470 may control the engine based on the finally identified second engine rotation angle CA.

[0116] In this case, the second engine rotation angle identifier 470 may control the engine by transmitting a torque command to the engine control unit 210 of the vehicle.

[0117] The first and second indexes stored in the memory may be used to estimate the second engine rotation angle again based on the stored first and second indexes and the rotor angle information of the electric motor when the engine is next started after the engine is shut down.

[0118] Figure 7It is shown that the synchronization operation unit according to the embodiment of the present disclosure estimates the first index and the second index and the second engine rotation angle.

[0119] For example, the resolver electrical angle of the motor directly connected to the engine acquired by the rotor angle acquirer 410 may be 40 degrees. In addition, the first engine rotation angle (Cacan) acquired by the first engine rotation angle acquirer 430 may be 640 degrees.

[0120] In this case, the engine rotation angle candidate generator 450 is based on the resolver electrical angle θ acquired by the rotor angle acquirer 410. e Generate candidates for the engine rotation angle CA. In this case, the generated candidates for the engine rotation angle can be represented, for example, as a matrix

[0121]

[0122] The second engine rotation angle identifier 470 can identify the second engine rotation angle as 640 degrees based on the minimum value "0" of the absolute value of the difference between the first engine rotation angle (Cacan) of "640" and the engine rotation angle candidates {10, 100, 190, 280, 370, 400, 550, 640} {630, 540, 450, 360, 270, 180, 90, 0}. In this case, because "640" is located in the fourth row and the second column of the candidate matrix of CA, the first index and the second index can be set to "4" and "2", respectively.

[0123] The first index and the second index may be set when the engine is first started, and may be updated each time the rotation angle of the motor increases by 360 degrees. The second engine rotation angle identifier 470 may estimate the second engine rotation angle based on the first index and the second index.

[0124] Furthermore, when the engine is not started for the first time, the second engine rotation angle may be estimated based on the first and second indexes stored in a memory or the like of the system.

[0125] Figure 8 is a flow chart describing an engine angular position estimation method according to an embodiment of the present disclosure.

[0126] The engine angular position estimation method according to this embodiment can be obtained by Figure 3 The synchronization operation unit 390 or is executed by the vehicle's corresponding hybrid control unit (HCU).

[0127] refer to Figure 8, the synchronization operation unit 390 identifies whether the engine is started for the first time (S810), and when the engine is started for the first time, increases the revolutions per minute (RPM) of the engine to a preset value (S820).

[0128] In this case, the preset RPM of the engine may have an arbitrary value, for example, 1000 RPM.

[0129] In addition, the synchronization operation unit 390 receives the rotor angle information of the motor generated by the rotor angle operation unit (S830).

[0130] In this case, the above rotor angle information of the electric motor can be generated based on information detected by the resolver.

[0131] In addition, the synchronization operation unit 390 receives the first engine rotation angle information generated by the engine rotation angle operation unit (S840).

[0132] In this case, the first engine rotation angle information may be generated based on information detected by a cam angle sensor or a crank angle sensor.

[0133] In addition, the synchronization operation unit 390 generates engine rotation angle candidates based on the rotor angle information (S850).

[0134] In this case, the engine rotation angle candidate may be generated based on Equation 3.

[0135] Furthermore, the synchronization operation unit 390 identifies first and second indexes based on the engine rotation angle candidates and the first engine rotation angle information (S860).

[0136] In this case, the first index (index1) corresponds to the value of N that matches the value of CA obtained in Equation 4. The second index (index2) indicates whether two candidates of CA corresponding to one value of N have a rotation angle less than or greater than 360 degrees, that is, whether the rotation angle is the value plus 360 degrees. For example, the second index may have a value of 1 or 2. In other words, when the motor is an 8-pole motor, the candidate of CA corresponding to the rotary transformer electrical angle θe can be represented by a 4*2 matrix, and the first and second indexes can represent the second engine rotation angle CA among the candidates of CA, and the second engine rotation angle CA is finally identified by the second engine rotation angle identifier 470.

[0137] Furthermore, the synchronization operation unit 390 identifies a second engine rotation angle based on the first and second indexes (S870).

[0138] In this case, the synchronization operation unit 390 may identify the second engine rotation angle based on the values ​​indicated by the first index and the second index among the candidates of the CA.

[0139] In addition, every time the rotation angle of the motor increases by 360 degrees, the synchronization operation unit 390 updates the first index and the second index (S880).

[0140] When it is identified in step S810 that the engine is not started for the first time, the pre-stored first index and second index are obtained (S890), and the second engine rotation angle is identified based on the obtained first index and second index (S870).

[0141] The identified second engine rotation angle CA may be used to control an engine of the vehicle.

[0142] In this case, the synchronization operation unit 390 may control the engine by transmitting the torque command to the engine control unit 210 of the vehicle.

[0143] The first index and the second index may be stored in a memory and used to estimate the second engine rotation angle again based on the stored first index and second index and the rotor angle information of the electric motor when the engine is next started after the engine is shut down.

[0144] Fig. 9 is a block diagram illustrating an engine angular position estimation system according to another embodiment of the present disclosure.

[0145] refer to Fig. 9 According to the embodiment, the engine angular position estimation system includes an engine 910, a first motor 920, a second motor 930, a transmission 940, an engine rotation angle calculation unit 950, a first rotor angle calculation unit 960, a second rotor angle calculation unit 970, a transmission control unit 980 and a synchronization calculation unit 990.

[0146] In addition, the engine 910 includes a cam angle sensor 911 . The first motor 920 includes a first resolver 921 . The second motor 930 includes a second resolver 922 .

[0147] exist Figure 3 In the illustrated embodiment, the engine 310 includes a cam angle sensor 311 and a crank angle sensor 313. The engine rotation angle calculation unit 350 generates a first engine rotation angle based on the detection results of the cam angle and the crank angle.

[0148] However, according to Fig. 9 In the embodiment described in , the engine 910 includes only the cam angle sensor 911. The engine rotation angle calculation unit 950 generates the first engine rotation angle based only on the detection result of the cam angle.

[0149] Fig.10 is a block diagram of an engine angular position estimation system according to yet another embodiment of the present disclosure.

[0150] Reference Fig.10 According to this embodiment, the engine angular position estimation system includes an engine 1010, a first motor 1020, a second motor 1030, a transmission 1040, an engine rotation angle calculation unit 1050, a first rotor angle calculation unit 1060, a second rotor angle calculation unit 1070 and a transmission control unit 1080.

[0151] Furthermore, the engine 1010 includes a cam angle sensor 1011 and a crank angle sensor 1013 , the first motor 1020 includes a first resolver 1021 , and the second motor 1030 includes a second resolver 1022 .

[0152] exist Figure 3 In the illustrated embodiment, the first engine rotation angle identified by the engine rotation angle calculation unit 350 is transmitted to the synchronization calculation unit 390, and the synchronization calculation unit 390 identifies the second engine rotation angle based on the first engine rotation angle.

[0153] However, according to Fig.10 In the embodiment described in FIG. 1 , two functions of the engine rotation angle calculation unit 350 and the synchronization calculation unit 390 are integrated into the engine rotation angle calculation unit 1050. Therefore, the engine rotation angle calculation unit 1050 recognizes the first engine rotation angle and the second engine rotation angle.

[0154] In this case, the engine rotation angle calculation unit 1050 may be implemented in the form of a hybrid engine control unit (HECU) integrating an engine control unit (ECU) and a hybrid control unit (HCU).

[0155] In this case, CAN communication between the HCU and the ECU is not required separately, thereby reducing time delay.

[0156] Fig.11A An example of a target wheel that may be used in a camshaft of an engine according to an embodiment of the present disclosure is shown. Fig. 11B Another example of a target wheel that may be used in a camshaft of an engine according to an embodiment of the present disclosure is shown.

[0157] In such Fig.11A In the case of the half-moon target wheel shown, not only a cam sensor but also a crankshaft angle sensor is required to accurately measure the rotation angle of the engine. Fig. 11B As shown, in the case of a target wheel having a plurality of protrusions, the rotation angle of the engine can be measured only by the cam sensor without the crank angle sensor.

[0158] Fig.12 is a block diagram of an engine angular position estimation system according to yet another embodiment of the present disclosure.

[0159] See also Fig.12 The engine angular position estimation system includes an engine 1210, a first motor 1220, a second motor 1230, a transmission 1240, an engine rotation angle calculation unit 1250, a first rotor angle calculation unit 1260, a second rotor angle calculation unit 1270, a transmission control unit 1280 and a synchronization calculation unit 1290.

[0160] In addition, the engine 1210 includes a cam angle sensor 1211 and a crank angle sensor 1213. The first motor 1220 includes a first resolver 1221. The second motor 1230 includes a second resolver 1222.

[0161] Compare Fig.12 The implementation method and Fig. 9 implementation method, Fig. 9 The embodiment shows that the first rotor angle operation unit 960 obtains the resolver electrical angle from the first resolver 921 provided in the first motor 920 directly connected to the engine 910 to generate the rotor angle of the motor. However, Fig.12 The embodiment of the present invention shows that the engine rotation angle calculation unit 1250 obtains the rotary transformer electrical angle from the first rotary transformer 1221 to generate the rotor angle of the motor. In addition, the engine rotation angle calculation unit 1250 can identify the rotor angle of the motor and the first engine rotation angle. In addition, the engine rotation angle calculation unit 1250 identifies the second engine rotation angle based on the rotor angle of the motor and the first engine rotation angle.

[0162] In this case, the synchronization operation unit 1290 may be implemented in the form of an HECU in which the ECU and the HCU are integrated.

[0163] In this case, CAN communication between the HCU and the ECU is not required separately, thereby reducing time delay.

[0164] According to the above-described embodiments of the present disclosure, when the performance or stability of the active noise control (ANC) system is degraded due to an error in the secondary path modeling, the angular position of the engine is estimated based on the resolver signal of the motor, the resolver of the motor having high resolution and being strong. As a result, it is possible to perform the main control of the engine at high resolution at accurate timing.

[0165] In addition, the crankshaft angle of the engine is processed in the same manner as the internal control of the engine previously performed. The motor synchronizes the angular position of the motor with the angular position of the engine, thereby smoothly performing vibration control that offsets the torque and speed changes of the motor through the motor.

[0166] In addition, the control of the engine is performed based on the existing engine crankshaft angle signal processing, the control of the motor is performed based on the existing resolver-based motor position signal, and the hybrid control unit that distributes the torque of the engine and the motor distributes the instantaneous torque in consideration of the phase of the engine and the motor. Therefore, the instantaneous torque of the motor can offset the change of the instantaneous torque of the engine, thereby smoothly performing vibration control that controls the change of the torque and speed of the engine through the motor at low RPM.

[0167] The present disclosure can be implemented as a computer-readable code on a medium having a program recorded thereon. Computer-readable media include any type of recording device that stores data that can be read by a computer system. For example, computer-readable media include hard disk drives (HDDs), solid-state disks (SSDs), silicon disk drives (SDDs), read-only memories (ROMs), random access memories (RAMs), compact disks (CDs)-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc. Therefore, the foregoing detailed description should not be interpreted as being restrictive in all aspects, and should be considered for purposes of illustration. The scope of the present disclosure should be determined by the reasonable interpretation of the appended claims, and any changes within the equivalent scope of the present disclosure are included within the scope of the present disclosure.

Claims

1. A vibration control method for a hybrid electric vehicle, the vibration control method comprising: receiving rotor angle information of the electric motor of the hybrid electric vehicle generated based on information detected by a resolver; receiving first engine rotation angle information of an engine of the hybrid electric vehicle generated based on information detected by a cam angle sensor or a crank angle sensor; generating a plurality of engine rotation angle candidates based on the rotor angle information; and A second engine rotation angle is identified based on the plurality of engine rotation angle candidates and the first engine rotation angle information.

2. The vibration control method according to claim 1, wherein: The number of the engine rotation angle candidates is based on the number of magnetic poles of a rotor magnet of a motor of the hybrid electric vehicle.

3. The vibration control method according to claim 1, wherein: Identifying the second engine rotation angle includes: identifying a first index and a second index based on the engine rotation angle candidates and the first engine rotation angle information; and The second engine rotation angle is identified based on the first index and the second index.

4. The vibration control method according to claim 3, further comprising: storing the first index and the second index in a memory; as well as When the engine of the hybrid electric vehicle is started next time after the engine is shut down, the second engine rotation angle is estimated again based on the stored first index and second index and the rotor angle information of the electric motor.

5. The vibration control method according to claim 3, wherein: The first index and the second index include values ​​for indicating one of the engine rotation angle candidates.

6. The vibration control method according to claim 1, further comprising: The engine is controlled based on the second engine rotation angle.

7. A hybrid electric vehicle comprising: a rotor angle calculation unit configured to generate rotor angle information of the electric motor of the hybrid electric vehicle based on information detected by the resolver; an engine rotation angle calculation unit configured to generate first engine rotation angle information of an engine of the hybrid electric vehicle based on information detected by a cam angle sensor or a crank angle sensor; as well as The synchronous operation unit is configured to generate a plurality of engine rotation angle candidates based on the rotor angle information, and to identify a second engine rotation angle based on the plurality of engine rotation angle candidates and the first engine rotation angle information.

8. The hybrid electric vehicle according to claim 7, wherein: The number of the engine rotation angle candidates is based on the number of magnetic poles of a rotor magnet of a motor of the hybrid electric vehicle.

9. The hybrid electric vehicle according to claim 7, wherein: The synchronization operation unit identifies a first index and a second index based on the engine rotation angle candidates and the first engine rotation angle information, and identifies the second engine rotation angle based on the first index and the second index.

10. The hybrid electric vehicle according to claim 9, wherein: The synchronous operation unit stores the first index and the second index in a memory, and when the engine is started next time after the engine is shut down, estimates the second engine rotation angle again based on the stored first index and the second index and the rotor angle information of the motor.

11. The hybrid electric vehicle according to claim 9, wherein: The first index and the second index include values ​​for indicating one of the engine rotation angle candidates.

12. The hybrid electric vehicle according to claim 7, wherein: The synchronous operation unit controls the hybrid electric vehicle to travel by controlling the engine based on the second engine rotation angle.

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