Motor control device

Abstract

Providing technology that can suppress the sound of teeth clicking. [Solution] The motor control device comprises an engine, a transmission to which the rotational driving force of the engine is transmitted, a first gear connected to the output shaft of the transmission, a motor, a second gear connected to the output shaft of the motor and meshing with the first gear, and a control unit that controls the motor based on a first gear waveform corresponding to the torque waveform input to the first gear, such that the second gear waveform corresponding to the torque waveform input to the second gear is in phase with the first gear waveform, wherein the control unit detects an engine waveform, which is the torque waveform output from the engine, and applies a bandpass filter to the engine waveform that allows the frequency band of vibrations caused by the engine's explosion to pass through, thereby identifying the first gear waveform input from the engine to the first gear via the transmission.

Description

Technical Field

[0001] The present invention relates to a motor control device.

Background Art

[0002] Conventionally, in a vehicle including a transmission and a motor, a technique for solving various problems occurring in the vehicle by controlling the motor is known. For example, in Patent Document 1, in a configuration in which a transmission and an engine are connected via a clutch damper and the transmission and a motor are connected, a band-pass filter is caused to act on damper torque with the frequency of the first engine explosion as a passing frequency, and torque of the reverse phase of the output from the band-pass filter is output from the motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology, it has not been possible to suppress the tooth meshing noise in a gear. Specifically, it is common that the transmission and the motor are connected via a gear, and when torque is transmitted from the transmission to the gear, tooth meshing noise due to the collision between the gears occurs.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of suppressing tooth meshing noise.

Means for Solving the Problems

[0006] A motor control device according to one embodiment includes an engine, a transmission to which the rotational driving force of the engine is transmitted, a first gear connected to the output shaft of the transmission, a motor, a second gear connected to the output shaft of the motor and meshing with the first gear, and a control unit that controls the motor based on a first gear waveform corresponding to the torque waveform input to the first gear, such that the second gear waveform corresponding to the torque waveform input to the second gear is in phase with the first gear waveform. The control unit detects an engine waveform, which is the torque waveform output from the engine, and applies a bandpass filter to the engine waveform that allows the frequency band of vibrations caused by the engine's explosion to pass through, thereby identifying the first gear waveform from the engine via the transmission. .

[0007] In other words, when the first gear is connected to the output shaft of the transmission and the second gear is connected to the output shaft of the motor, and the first and second gears mesh, a gear noise can be generated due to the contact between the first and second gears. Furthermore, the vibrations that cause the gear noise are vibrations caused by the explosion output from the engine. Therefore, the control unit passes the vibrations caused by the explosion through a bandpass filter, removes other vibrations, and identifies the waveform of the first gear based on the removed signal. The control unit then controls the motor so that the waveform of the second gear is in phase with the waveform of the first gear. When the waveform of the second gear is in phase with the waveform of the first gear, the collision between the first and second gears is prevented or suppressed. As a result, the gear noise can be suppressed. Moreover, because the control is performed based on the vibrations caused by the explosion that cause the gear noise, the gear noise can be suppressed more effectively compared to a configuration in which the first gear waveform is identified when vibrations other than those caused by the explosion are present. [Brief explanation of the drawing]

[0008] [Figure 1] A block diagram showing the schematic configuration of a vehicle and its control unit according to one embodiment. [Figure 2] A block diagram showing an example of the internal configuration of the control unit. [Figure 3] A flowchart illustrating the motor control process. [Figure 4] Figure 4A shows the Nereal waveform for engine speed, and Figure 4B shows an example of the waveform after applying a bandpass filter to the engine speed. [Figure 5] Figure 5A shows the gain at each frequency when the filter is applied, and Figure 5B shows the phase change at each frequency when the filter is applied. [Figure 6] Figure 6A shows the gain at each frequency when the filter is applied, and Figure 6B shows the phase change at each frequency when the filter is applied. [Figure 7] Figure 7A shows the gain at each frequency when the filter is applied, and Figure 7B shows the phase change at each frequency when the filter is applied. [Figure 8] A diagram showing the torque related to the second gear. [Figure 9] A diagram showing a model of the system including the engine, clutch damper, transmission, motor, first gear, and second gear. [Figure 10] Figure 10A shows the rotational waveform of engine 1, and Figure 10B shows the difference in period length. [Figure 11] Figure 11A shows the engine waveform (EG), first gear waveform, and second gear waveform in terms of torque, illustrating an example where the command torque waveform is a sine wave. Figure 11B shows the engine waveform (EG), first gear waveform, and second gear waveform in terms of rotational speed. [Figure 12] Figure 12A shows the engine waveform (EG), first gear waveform, and second gear waveform in relation to torque, illustrating an example where the command torque waveform is a triangular wave. Figure 12B shows the engine waveform (EG), first gear waveform, and second gear waveform in relation to rotational speed. [Figure 13] Figure 13A shows the engine waveform (EG) and first gear waveform of an engine-based system with respect to torque, and Figure 13B shows the engine waveform (EG) and first gear waveform of an engine-based system with respect to rotational speed. [Figure 14]FIG. 14A is a diagram showing the engine waveform (EG) and the first gear waveform of the system using an engine with respect to torque, and FIG. 14B is a diagram showing the engine waveform (EG) and the first gear waveform of the system using an engine with respect to rotational speed. [Figure 15] FIG. showing a configuration example of a system for suppressing gear rattle. [Figure 16] FIG. showing a configuration example of a system for suppressing gear rattle.

MODE FOR CARRYING OUT THE INVENTION

[0009] Here, embodiments of the present invention will be described in the following order. (1) Configuration of motor control device: (2) Motor control process: (3) Derivation of command torque rTff: (4) Update of command torque rTff: (5) Waveform deformation: (6) Other embodiments, etc.:

[0010] (1) Configuration of motor control device: FIG. 1 is a block diagram showing a schematic configuration of a vehicle and its control unit 20 according to an embodiment. This vehicle includes an engine 1, a clutch damper 2, a transmission 3, and a motor 4. The engine 1 is connected to the input shaft 3a of the transmission 3 via the clutch damper 2, and the motor 4 is connected to the output shaft 3b of the transmission 3 via the first gear 5 and the second gear 6. The vehicle according to this embodiment is a series hybrid vehicle in which the motor 4 is rotated by the power of the engine 1, the electric power generated by the rotation of the motor 4 is charged into the battery, and the vehicle is driven by the electric power of the battery.

[0011] The engine 1 is equipped with a crank angle sensor 11. The crank angle sensor 11 detects the crank angle θ1 of the engine 1. The vehicle includes a control unit 20. The control unit 20 is composed of a processor, a memory, etc., and can execute a predetermined program. Of course, some or all of the functions of the control unit 20 may be realized by hardware. The control unit 20 performs control to suppress the tooth meshing noise generated by the contact between the first gear 5 and the second gear 6 based on the detection result of the crank angle sensor 11.

[0012] FIG. 2 is a block diagram showing an example of the configuration of the control unit 20. The control unit 20 functions as a control necessity determination unit 21, a frequency calculation unit 22, a band-pass filter 23, a waveform analysis unit 24, a command torque calculation unit 25, and a phase compensation unit 26.

[0013] The control necessity determination unit 21 is a function for determining whether to perform control of the motor 4 to suppress the tooth meshing noise. The control start condition for determining whether to perform control is determined in advance. In the present embodiment, when torque continuously acts from one of the first gear and the second gear to the other and the state where the backlash is clogged and meshed is continued, the control start condition is not satisfied. Therefore, a situation where the backlash is not clogged and tooth meshing noise can occur is defined as the control start condition. Specific examples of the control start condition will be described later. The control unit 20 obtains the rotational speed Nereal of the engine 1 based on the output of the crank angle sensor 11. Then, the control unit 20 determines whether the control start condition is satisfied based on the rotational speed Nereal by the function of the control necessity determination unit 21, and when the control start condition is satisfied, causes the command torque calculation unit 25 to output a command torque rTff.

[0014] The frequency calculation unit 22 is a function for calculating the frequency of the primary vibration of the engine 1, that is, the vibration caused by the up-and-down movement of the piston accompanying the explosion of the engine, based on the average value Neave of the rotational speed Nereal.

[0015] The bandpass filter 23 is a filter that allows signals in a specific frequency band to pass through the input signal. In this embodiment, the control unit 20 applies the bandpass filter 23 to the signal waveform indicating the rotational speed Nereal of the engine 1 (hereinafter also referred to as the rotation waveform) and outputs the signal that passes through the specific frequency band. In this embodiment, multiple types of filters can be selected for the bandpass filter 23, and the type of filter is selected according to the frequency of the primary vibration of the engine 1 calculated by the frequency calculation unit 22. Note that different filters have different transfer functions.

[0016] As a result, a filter that matches the frequency of the rotation waveform of engine 1 can be selected. That is, depending on the frequency of the primary vibration of engine 1, a filter can be selected that efficiently passes signals in the frequency band including that frequency and attenuates signals in other frequency bands. Furthermore, in a configuration where a single filter is applied even when the frequencies of the rotation waveform of engine 1 are different, it becomes necessary to use a filter with a small Q value. However, with a configuration that selects a filter that matches the frequency of the rotation waveform of engine 1, it is not necessary to make the Q value excessively small, and it is possible to apply a filter with a large Q value to the rotation waveform of each frequency.

[0017] Using a filter with a large Q value results in a smaller transfer gain and a larger phase lag. As a result, in the signal after applying the bandpass filter 23, the signal corresponding to the primary oscillation that should be retained is attenuated, and the phase shift becomes larger. However, by selecting a filter that matches the frequency of the rotation waveform of engine 1, it is possible to design the filter so that the gain is large at the frequencies that should be passed. Furthermore, it becomes possible to use a filter with a large Q value, making it possible to retain the necessary frequencies and attenuate the unnecessary frequencies.

[0018] Furthermore, the rotational waveform of engine 1 can be converted into torque output from the output shaft of engine 1 in terms of that rotational waveform. That is, the rotational waveform of engine 1 corresponds to the torque waveform of the torque output from engine 1 (for example, the torque is obtained by differentiating the rotational speed, which has a sinusoidal waveform, with respect to time). In this embodiment, both the rotational waveform of engine 1 and the torque waveform of the torque output from engine 1 are referred to as the engine waveform corresponding to the torque waveform output from engine 1. A configuration that performs analysis based on one or both of the rotational waveform and torque waveform of engine 1 can be said to be a configuration that performs analysis based on the engine waveform. For this reason, a configuration in which a filter is selected according to the frequency of the primary oscillation of the rotational waveform of engine 1, as in this embodiment, can be considered a configuration that changes the transfer function of the bandpass filter according to the frequency of the engine waveform.

[0019] The waveform analysis unit 24 performs analysis based on the signal waveform after applying the bandpass filter 23 to the rotation waveform of the engine 1, and has the function of determining the control start timing of the motor 4. Furthermore, in this embodiment, the waveform analysis unit 24 determines the torque amplitude corresponding to the rotation waveform of the engine 1, i.e., the amplitude of the torque waveform of the engine 1, based on the signal for one cycle of the engine's rotation waveform. The waveform analysis unit 24 also determines the control start timing of the motor 4 in synchronization with the period of the rotation waveform of the engine 1, based on the signal for one cycle of the engine's rotation waveform. Details of this process will be described later.

[0020] The torque output from engine 1 is transmitted to transmission 3 via clutch damper 2, and the torque from the output shaft 3b of transmission 3 is transmitted to the first gear 5. Furthermore, the torque waveform of engine 1 corresponding to the torque output at engine speed Nereal corresponds to the torque waveform generated at the output shaft 3b of transmission 3, that is, the torque waveform of the first gear 5, which is the torque waveform input to the first gear 5. The process of determining the control start timing of motor 4 based on one period of the waveform after applying the bandpass filter 23 to the rotational waveform of engine 1, which is the engine waveform, can be said to be the process of determining the control start timing of motor 4 based on one period of the torque waveform of the first gear 5, which corresponds to the engine waveform.

[0021] The torque waveform of the torque input to the first gear 5 can be converted into a rotational waveform that indicates the rotational speed of the first gear 5 in that torque waveform. In other words, the rotational waveform of the first gear 5 corresponds to the torque waveform of the torque input to the first gear 5. For this reason, both the rotational waveform of the first gear 5 and the torque waveform of the torque output from the first gear 5 can be called the first gear waveform corresponding to the torque waveform output from the first gear 5. Furthermore, a configuration that performs analysis based on one or both of the rotational waveform and torque waveform of the first gear 5 can be said to be a configuration that performs analysis based on the first gear waveform. Accordingly, the process of determining the control start timing of the motor 4 based on one period of the waveform after applying the bandpass filter 23 to the rotational waveform of the engine 1, which is the engine waveform, can be said to be a process of determining the control start timing of the motor 4 based on one period of the first gear waveform.

[0022] The command torque calculation unit 25 is a function that calculates the command torque, which indicates the torque to be generated by the motor 4. In this embodiment, the command torque rTff is determined by the following formula based on the amplitude Td of the fluctuation relative to the average of the torque waveform of the engine 1 for one cycle, which is identified by the waveform analysis unit 24, the frequency freal of the rotation waveform of the engine 1, and the gain α from the output shaft of the engine 1 to the output shaft of the motor 4. rTff=α·Td·cos(2π·freal·t+Ψ) Furthermore, Ψ is the torque transmission delay, which is determined by the phase compensation unit 26 described later.

[0023] The command torque rTff output by the command torque calculation unit 25 is the torque waveform that should be output from the motor 4 when the torque waveform of the engine 1 is Td·cos(2π·freal·t). Here, as a result of the motor 4 being controlled by the command torque rTff, the torque output from the motor 4 is input to the second gear 6.

[0024] The torque waveform of the torque input to the second gear 6 can be converted into a rotational waveform that indicates the rotational speed of the second gear 6 in that torque waveform. In other words, the rotational waveform of the second gear 6 corresponds to the torque waveform of the torque input to the second gear 6. For this reason, both the rotational waveform of the second gear 6 and the torque waveform of the torque output from the second gear 6 can be called the second gear waveform corresponding to the torque waveform output from the second gear 6. Furthermore, a configuration that performs analysis based on one or both of the rotational waveform and torque waveform of the second gear 6 can be said to be a configuration that performs analysis based on the second gear waveform.

[0025] The control unit 20 outputs rTff from the command torque calculation unit 25 to the motor 4 and controls the motor 4 to output the command torque. Various known methods can be used for torque control. The derivation of the command torque rTff will be described later, but by controlling the motor 4 to output the command torque rTff, the rattling noise between the first gear 5 and the second gear 6 can be suppressed.

[0026] The phase compensation unit 26 has the function of compensating for the delay that occurs between the detection of the engine waveform of engine 1 and the input of torque corresponding to the torque output by motor 4 to the second gear 6. In other words, there is a time lag between the detection of the engine waveform of engine 1 and the input of torque to the second gear 6 by motor 4. This lag is called a delay. In this embodiment, the amount of this delay (phase delay) includes the response delay in the system including engine 1, clutch damper 2, transmission 3, motor 4, first gear 5, and second gear 6, and the delay due to the time required for processing by the control unit 20. Here, the former delay is called the response delay, and the latter the processing delay.

[0027] In this embodiment, the control unit 20 uses the function of the phase compensation unit 26 to identify Ψ, which represents the amount of phase delay corresponding to the response delay, and performs phase compensation by substituting it into Ψ in the equation for rTff described above. The control unit 20 also uses the function of the phase compensation unit 26 to identify the amount of phase delay corresponding to the processing delay. In this embodiment, the amount of phase delay corresponding to the processing delay may include various delays, such as the delay caused by the process of applying the bandpass filter 23, the delay caused by the process of calculating the command torque rTff based on the output of the crank angle sensor 11, and the delay corresponding to the period from when the motor 4 is controlled based on the command torque rTff until the torque is output.

[0028] In this embodiment, the amount of phase delay corresponding to processing delay is a predetermined amount. That is, the delay caused by each process is measured in advance, converted into a phase delay amount, and stored in a memory (not shown). The control unit 20 acquires Ψp, which represents the amount of phase delay, and adds it to Ψ to determine a phase value to compensate for the total amount of phase delay. If the amount of phase delay corresponding to processing delay fluctuates depending on conditions, for example, if the amount of phase delay fluctuates depending on the processing load of the control unit 20, it is possible to adopt a configuration in which a map showing the relationship between conditions such as processing load and the amount of phase delay corresponding to processing delay is generated in advance, and the control unit 20 determines the amount of phase delay according to the conditions.

[0029] (2) Motor control processing: Next, the motor control process performed by the control unit 20 will be explained using a flowchart. Figure 3 is a flowchart of the motor control process. The motor control process is performed by the control unit 20 in response to a predetermined trigger. The predetermined trigger can be defined in various ways. For example, the start of power supply to the vehicle's electrical components, the passage of a certain period of time, etc., can be triggers. In this embodiment, the motor control process is performed with the start of power supply to the vehicle's electrical components as the trigger. The motor control process is a process that feedforward controls the motor 4 by a command torque rTff, and the command torque rTff is a fixed value. However, the command torque rTff is updated when the change in the torque waveform of the engine 1 exceeds a standard. The process for determining whether or not the change in the torque waveform of the engine 1 exceeds a standard will be described later.

[0030] When motor control processing begins, the control unit 20 determines whether the control start conditions have been met using the control necessity determination unit 21 (step S100). The control start conditions indicate a situation in which backlash does not occur and a rattling noise may occur. In this embodiment, the following conditions are defined. (A) When engine 1 is running (B) When the average value of the torque of engine 1 is approximately 0, or when the fluctuation range of the torque of engine 1 > the average value. (C) When the required torque of motor 4 is approximately 0, or when the torque fluctuation range of engine 1 > average value.

[0031] Under condition (A), when engine 1 is operating, the rotation of the second gear 6 does not follow the rotation of the first gear 5 accompanying the rotation of engine 1, which may cause a gear noise. Under condition (B), when the average value of engine 1's torque is approximately 0, torque is not continuously transmitted from the first gear 5 to the second gear 6. However, even in this state, if torque fluctuations occur due to explosion fluctuations of engine 1, a gear noise may occur. Also, under condition (C), when the motor 4's required torque is approximately 0 (for example, when the battery SOC is 100% during regenerative operation and cannot be charged), the output torque of engine 1 cannot be transmitted to motor 4. Therefore, even in this state, if torque fluctuations occur due to explosion fluctuations of engine 1, a gear noise may occur. Furthermore, if the torque fluctuation range of engine 1 > average value, the torque transmitted from the first gear 5 to the second gear fluctuates excessively relative to the average value, which may cause a gear noise.

[0032] The control unit 20 determines that the control start condition has been met if at least one of the above conditions is met. For example, (A) can be configured to consider the control start condition to have been met from a reference timing such as turning on the ignition until a predetermined period of time has elapsed, until the rotational speed of the engine 1 reaches a predetermined rotational speed or higher, or until the output torque of the engine 1 reaches a predetermined value or higher. For conditions (B) and (C), the control unit 20 may make the determination based on the torque specified based on the rotational speed Ne of the engine 1, or it may make the determination based on various torque sensors.

[0033] If, in step S100, it is determined that the control start condition is not met, the control unit 20 sets the command torque rTff calculated by the command torque calculation unit 25 to 0 (step S150). As a result, control for suppressing gear noise is not effectively performed.

[0034] In step S100, if it is determined that the control start condition has been met, the control unit 20 uses the function of the frequency calculation unit 22 to obtain the engine speed Nereal and average value Neave based on the output of the crank angle sensor 11 (step S105). The average value Neave is the time average of the engine speed Nereal of engine 1, and the control unit 20 obtains the average value Neave by dividing the sum of the engine speed Nereal values ​​sampled during a predetermined time by the number of samples.

[0035] Figure 4A shows an example of the engine speed Nereal waveform, i.e., the rotational waveform, and the average value Neave. In the example shown in Figure 4A, the dashed line represents the average value Neave, which in this example is 1000 rpm. As shown in Figure 4A, the rotational waveform of engine 1 is a waveform that oscillates sinusoidally around the average value Neave. In addition, the rotational waveform oscillates sinusoidally but also includes minute oscillations of higher frequencies. In this example, the waveform with period Tne that changes sinusoidally is the primary oscillation of engine 1, i.e., the waveform of the oscillation caused by the explosion of engine 1.

[0036] Next, the control unit 20 obtains the frequency of the primary oscillation using the function of the frequency calculation unit 22 (step S110). Specifically, the control unit 20 obtains the frequency f (Hz) of the primary oscillation based on the average value Neave obtained in step S105, according to the following formula. f = (Neave / 60) * (Number of cylinders in engine 1) / 2 The frequency f of the primary vibration may be obtained based on various other equations. With this configuration, the gear noise caused by the torque transmitted to the first gear 5 in response to the explosion of engine 1 can be identified as the target for suppression.

[0037] Next, the control unit 20 selects a bandpass filter based on the frequency of the primary oscillation using the function of the bandpass filter 23 (step S115). Specifically, the control unit 20 refers to a map that associates frequencies with types of bandpass filters and selects a filter corresponding to the frequency obtained in step S110. Through this process, the control unit 20 changes the transfer function of the bandpass filter according to the frequency of the primary oscillation.

[0038] Next, the control unit 20 applies a bandpass filter to the engine speed Nereal using the function of the bandpass filter 23 (step S120). That is, the filter selected in step S115 is applied to the rotation waveform. Figure 4B shows the waveform after applying the filter selected based on the period Tne to the rotation waveform shown in Figure 4A. As shown in Figure 4B, in the waveform after the filter is applied, the vibration at the frequency of the primary vibration remains, while other vibrations, such as minute vibrations superimposed on the primary vibration, are removed. In addition, in the waveform after the filter is applied, only the fluctuating component remains, and the center of the vibration is 0.

[0039] With the above configuration, it is possible to retain the vibrations caused by the explosion of engine 1, which are the source of the gear noise, while eliminating other vibrations. Figures 5A, 5B, 6A, 6B, 7A, and 7B are diagrams illustrating the effect of being able to select filters. These figures are Bode plots showing the transfer characteristics of different filters. Specifically, Figures 5A, 6A, and 7A show the gain at each frequency when the filters are applied, and Figures 5B, 6B, and 7B show the phase change at each frequency when the filters are applied.

[0040] Figure 5A shows the frequency range Δf that can be the frequency of the primary oscillation in this embodiment. If a single bandpass filter applicable to all frequencies in this range Δf is prepared, the filter will have the highest gain at a specific frequency within the range Δf. For example, as shown in Figure 5A, the filter with the highest gain at the center of the range Δf is prepared. However, in this case, the gain will be small at other frequencies in the range Δf. For example, the gain will be considerably small at frequencies f1 and f2. Also, the amount of phase change will be large. Even if a single filter with a small Q value and high gain over a wide range is prepared, in that case, the oscillations to be removed will not be sufficiently attenuated, and the phase change will be even larger.

[0041] In this embodiment, a filter is selected according to the frequency of the primary vibration, and as a result, the transfer function of the filter is changed. That is, the control unit 20 selects a filter from among pre-prepared filters that has the maximum gain at the frequency of the primary vibration. Figures 6A and 6B show the characteristics of a filter that has the maximum gain and the minimum phase change at frequency f3, and Figures 7A and 7B show the characteristics of a filter that has the maximum gain and the minimum phase change at frequency f4. These filters have a larger Q value than the filters shown in Figures 5A and 5B. Therefore, although these filters allow vibrations of a narrower frequency to pass through, in this embodiment the control unit 20 can select a filter according to the frequency of the primary vibration, so it can select a filter that does not excessively attenuate vibrations at the frequency of the primary vibration. Furthermore, phase shift can also be suppressed.

[0042] Next, the control unit 20 identifies the torque waveform of engine 1 from the engine speed Nereal using the functions of the waveform analysis unit 24 (step S125). In this embodiment, the control unit 20 identifies the torque waveform of engine 1 based on the waveform after applying the bandpass filter 23 to the rotation waveform (hereinafter referred to as the filtered waveform). The torque waveform of engine 1 is defined by the amplitude of the torque output to the output shaft of engine 1, the torque frequency, and the start timing of the torque waveform. That is, a sine wave that changes with the acquired frequency and amplitude after the start timing is considered to be the torque waveform of engine 1.

[0043] The rotational waveform and torque waveform of engine 1 have a predetermined relationship. Assuming both waveforms are sine waves, the torque waveform of engine 1 can be obtained by shifting the phase of the rotational waveform by 1 / 4 period (-π / 2 minutes). In this embodiment, based on this relationship, the torque waveform of engine 1 is obtained based on the waveform after filtering by applying a bandpass filter 23 to the rotational waveform.

[0044] To identify the torque waveform of engine 1, the control unit 20 first identifies the start timing of the torque waveform of engine 1. Specifically, the control unit 20 compares the filtered waveform with a predetermined value to identify the start timing that serves as the base point for analyzing the filtered waveform. In this embodiment, the timing at which the filtered waveform crosses zero is considered the start timing of the filtered waveform. Since the torque waveform of engine 1 can be generated by shifting the phase of the filtered waveform by 1 / 4 period (-π / 2 min), the control unit 20 identifies one period of the filtered waveform based on the zero crossing of the filtered waveform. Then, the control unit 20 identifies the start timing of the torque waveform of engine 1 by shifting the waveform of that one period by 1 / 4 period (-π / 2 min). Furthermore, the control unit 20 identifies the torque amplitude (maximum value of change from zero) based on the waveform of one period of the filtered waveform. In this embodiment, the torque amplitude can be identified by a conversion map of the engine speed and torque value of engine 1 that has been identified in advance. Here, the amplitude of the obtained torque is denoted as amplitude Td.

[0045] The frequency is considered to be the same in the filtered waveform and the torque waveform of engine 1. Therefore, the control unit 20 identifies the frequency freal based on the time length of one cycle of the filtered waveform and considers it to be the frequency freal of the torque waveform of engine 1.

[0046] Next, the control unit 20 determines the command torque rTff using the function of the command torque calculation unit 25 (step S130). That is, the control unit 20 determines the command torque rTff as rTff = α·Td·cos(2π·freal·t+Ψ). At this time, the control unit 20 substitutes the torque amplitude Td and frequency freal, which were determined in step S125, into the equation. Details of the calculation method for the gain α and the phase value Ψ for compensating for the delay will be described later. In step S125, the gain α is determined, but the phase value Ψ is determined in step S135.

[0047] The command torque rTff is set so that the torque waveform of the second gear 6 is in phase with the torque waveform of the first gear 5. Specifically, when the motor 4 is controlled by the command torque rTff, a torque of a predetermined torque waveform is input from the motor 4 to the second gear 6. When the engine 1 operates, a torque of a predetermined torque waveform is input to the first gear 5 via the transmission 3. In the motor 4, the command torque rTff is set so that the torque waveform of the second gear is in phase with the torque waveform of the first gear 5. As a result, the first gear and the second gear do not collide or the collision is mitigated. As a result, gear noise can be suppressed.

[0048] Next, the control unit 20 performs delay compensation using the function of the phase compensation unit 26 (step S130). Figure 8 is a diagram showing the torque related to the second gear 6. In Figure 8, the torque waveform of the second gear 6 without delay compensation is shown by a solid black line, the torque waveform of the second gear 6 with delay compensation is shown by a solid gray line, and the torque waveform of the second gear 6 synchronized with the torque waveform of the engine 1 is shown by a dashed black line.

[0049] Without delay compensation, the torque waveform of the second gear 6 will experience response delay and processing delay. The solid black line in Figure 8 shows the torque waveform of the second gear 6 when no delay compensation is performed for such delays. The torque waveform of the second gear 6, which is in phase with the torque waveform of the first gear 5, is shown by the dashed line, and there is a delay of amount D between the torque waveform of the second gear 6 shown by the dashed line and the torque waveform of the second gear 6 shown by the solid line. Therefore, the control unit 20 identifies the amount of delay D and performs phase delay compensation by advancing the phase of the torque waveform of the second gear 6 by the amount of delay D.

[0050] Specifically, the control unit 20 identifies a phase value Ψ corresponding to the response delay based on the specifications of the engine 1 and transmission 3, such as the moment of inertia, and the frequency freal of the torque waveform of the engine 1, using equations (18) and the second equation of equation (22), which will be described later. The control unit 20 also obtains a phase value Ψp that has been previously identified as the phase value corresponding to the processing delay by referring to memory. The control unit 20 identifies a phase for delay compensation by summing the phase value Ψ corresponding to the response delay and the phase value Ψp corresponding to the processing delay.

[0051] When the phase value is determined, the control unit 20 determines the command torque rTff using the formula rTff = α·Td·cos(2π·freal·t+Ψ+Ψp). Then, the control unit 20 controls the motor 4 according to the command torque rTff. Through this process, the motor 4 is controlled without any delay between the output of torque from the engine 1 and the output of the second gear input torque. Therefore, gear noise can be suppressed with high precision.

[0052] In this embodiment, the control unit 20 analyzes one cycle of the rotation waveform of the engine 1 (or one cycle of the torque waveform of the engine 1) to determine the torque amplitude Td, frequency freal, etc. Therefore, at least one cycle of analysis is required before starting control of the motor 4 in order to apply torque to the second gear 6. Thus, the control unit 20 starts controlling the motor 4 after analyzing one cycle of the rotation waveform (or the torque waveform of the engine 1). The control unit 20 sets the motor 4 control start timing to one cycle after the start timing of the torque waveform of the engine 1 identified in step S125 above. The control unit 20 then executes control using the commanded torque rTff with phase delay compensation after the control start timing. Through the above process, the amplitude, frequency, and control start timing of the torque waveform of the second gear 6 can be identified and control can be performed, making it easy to suppress gear noise.

[0053] Furthermore, this control can be initiated by specifying the amplitude, frequency, and control start timing of the torque waveform of the second gear 6, and control can be performed based on a common command torque rTff until the change in the torque waveform of the engine 1 exceeds a reference (details will be described later). Therefore, the motor 4 can be feedforward controlled so that the torque waveform of the first gear 5 is in phase with the torque waveform of the second gear 6. For this reason, compared to performing feedback control, it is not necessary to constantly monitor sensor outputs such as the output of the crank angle sensor 11, and control can be performed in a simpler manner.

[0054] Furthermore, in this embodiment, since the control start timing is determined based on the zero crossing of the rotation waveform (which may also be the torque waveform of engine 1), processing related to waveforms that change over time can be easily performed. Moreover, in this embodiment, since the vibration for one cycle of the rotation waveform (which may also be the torque waveform of engine 1) is measured, the amplitude, frequency, and control start timing of the torque waveform of the second gear 6 can be easily and accurately determined.

[0055] (3) Derivation of command torque rTff: Next, we will describe in detail an example of deriving the command torque rTff. In this embodiment, we construct a system model including the engine 1, clutch damper 2, transmission 3, motor 4, first gear 5, and second gear 6 shown in Figure 1. Figure 9 is a diagram of this model. Specifically, the engine 1 is modeled as a system having a moment of inertia I1, rotating at an angle θ1, and the torque waveform of the torque applied to the engine 1, i.e., the torque input to the engine 1, is Ti. The clutch damper 2 is modeled as a system with coefficient K1 corresponding to the spring component and coefficient C1 corresponding to the damper component. The transmission 3 is modeled as a system having a moment of inertia I2, rotating at an angle θ2, and inputting torque to the first gear 5. The motor 4 is modeled as a system having a moment of inertia I3, rotating at an angle rθ3, and the torque waveform of the torque input to the motor 4 is torque To. The first gear 5 has a radius of ri, and the second gear 6 has a radius of ro. The coefficients kc and c correspond to the spring component and damper component, respectively, in the first gear 5 and the second gear 6. c It is modeled as such a system. Note that each moment of inertia and coefficient can be determined in advance by measurements using the actual engine 1, clutch / damper 2, transmission 3, motor 4, first gear 5, and second gear 6 in the vehicle.

[0056] The rotational equation of motion for the system represented by the above model is given by equation (1). Here, xc is the displacement of the part where the first gear 5 and the second gear 6 mesh.

number

[0057] Here, the circumference of the changed part of each gear is expressed by equation (2).

number

number

[0058] Then, in order to express the displacement xc in a simplified way, we substitute equation (4):

number

number

[0059] Furthermore, by multiplying the third equation in equation (5) by r, equation (5) is transformed into equation (6).

number

[0060] Here, by redefining it as in equation (7), equation (6) is transformed into equation (8).

number

number

[0061] Here, assuming that a periodic oscillation Td·cos(ω·t) (=Td·cos(2πfreal·t)) is input to a certain system, the output becomes αTd·cos(ω·t+ψ) (=αTd·cos(2πfreal·t+ψ)). Therefore, the command torque rTff, which is used for feedforward control in response to the torque rTo input to motor 4, can be expressed by equation (9).

number

[0062] By substituting Ti and To in equation (8) based on the above expressions, we obtain equation (10).

number

[0063] In this embodiment, it is necessary to set the command torque rTff so that the torque waveform of the second gear 6 is in phase with the torque waveform of the first gear 5. As described above, both the torque waveform and the rotational waveform of the first gear 5 and the second gear 6 can be considered to be waveforms corresponding to torque. In this state, the gears are not in contact, so x in equation (3) c Since θ is 0, in equation (10), the angles θ2 of the first gear 5 and θ3 of the second gear 6 are such that θ2 = θ3, and furthermore, their time derivatives (represented by dots) are equal. The process of making the angle θ2 of the first gear 5 equal to the angle θ3 of the second gear 6 and making their interaxial derivatives equal corresponds to the process of making the second gear waveform in phase with the first gear waveform based on the first gear waveform.

[0064] Applying the above relationship to equation (10), it is transformed into equation (11).

number

[0065] In equation (11) above, the command torque rTff can be determined by finding θ2. Then, taking the Laplace transform of equation (11) yields equation (12).

number

[0066] Here, if we set s = jω to find the frequency characteristics of the system, we can transform equation (12) into equation (13).

number

[0067] Furthermore, by adding the first and second equations of equation (13), we obtain equation (14).

number

number

[0068] Rearranging equation (15) yields equation (16).

number

[0069] Substituting equation (16) into equation (14) and simplifying, we can arrive at equation (17).

number

[0070] Here, by redefining the variables as in equation (18) and rearranging equation (17), we obtain equation (19). Note that ω can be determined from the relationship ω = 2πfreal.

number

number

[0071] Substituting the result of equation (19) into equation (13), we obtain equation (20), and from equation (20), the transfer function can be obtained as shown in equation (21).

number

number

[0072] According to equation (21), the gain α in the system's transfer function is given by the first equation of equation (22), and the phase value Ψ is given by the second equation of equation (22).

number

[0073] The control unit 20 identifies the amplitude Td, frequency freal, and start timing of the torque waveform Ti of engine 1 based on the rotational waveform of engine 1. Meanwhile, the control unit 20 identifies the gain α by the first equation of equation (22) based on the amplitude Td, frequency freal, and values ​​such as moment of inertia and coefficients corresponding to the specifications of engine 1, etc. Once the gain α is identified, the control unit 20 identifies the amplitude αTd of the torque waveform of the second gear 6 based on the gain α and amplitude Td. Furthermore, the control unit 20 identifies the phase value Ψ corresponding to the response delay by the second equation of equation (2). The control unit 20 also identifies the phase value Ψp corresponding to the processing delay by referring to memory. Then, the control unit 20 identifies the command torque rTff as rTff = α·Td·cos(2π·freal·t+Ψ+Ψp). Once the command torque rTff is identified, the control unit 20 outputs the command torque rTff to the motor 4 so that control is started at the control start timing. The above process makes it possible to suppress the rattling noise between the first gear 5 and the second gear 6.

[0074] (4) Update of commanded torque rTff: In the above process, once the control unit 20 identifies the command torque rTff based on one cycle of the rotation waveform of the engine 1, it can continue control using a common value as the command torque rTff. In other words, feedforward control can be performed. However, the value used to identify the command torque rTff includes the torque amplitude Td and frequency freal identified from the rotation waveform of the engine 1. For this reason, it is preferable to update the command torque rTff when the operation of the engine 1 fluctuates.

[0075] In this embodiment, the control unit 20 controls the motor based on a common command value (command torque rTff in this embodiment) until the change in the torque waveform of the engine 1 exceeds a reference value, and updates the command value when the change in the torque waveform of the engine 1 exceeds the reference value. The characteristics of the torque waveform of the engine 1 can also be analyzed using the characteristics of the rotation waveform of the engine 1 as described above.

[0076] In this embodiment, the control unit 20 determines whether the change in the rotational waveform of the engine 1 exceeds a reference. Specifically, the control unit 20 determines whether the change in the period of the rotational waveform exceeds a reference. For this purpose, the control unit 20 determines the period length (the time length of one period) of the rotational waveform of the engine 1 based on the zero crossing of the rotational waveform.

[0077] For example, in the rotational waveform of engine 1 shown in Figure 10A, the control unit 20 measures the time length from the zero-cross timing t1 to the next zero-cross timing t2 and considers it as the period length. The control unit 20 measures this period length for each period and identifies the difference from the period length of the previous period. Figure 10B is a graph showing the difference in period length corresponding to the rotational waveform shown in Figure 10A. For example, once the time length from timing t1 to timing t2 is obtained, the control unit 20 calculates the difference from the period length of one period prior to timing t1 and obtains the difference ΔT2.

[0078] The control unit 20 repeatedly performs the process of acquiring the difference in period length as described above, and compares the difference with a threshold. The threshold is a predetermined threshold used to evaluate whether the torque waveform of engine 1 has deformed enough to warrant updating the command torque rTff. In Figure 10B, the threshold is shown by a dashed line. In Figure 10B, it is assumed that the difference calculated by the control unit 20 at timing t4 exceeds the threshold.

[0079] If the difference exceeds the threshold, the control unit 20 updates the command torque rTff. That is, it executes the motor control process shown in Figure 3 again to determine the command torque rTff. When executing the motor control process shown in Figure 3, the amplitude, frequency, and control start timing of the torque waveform of the second gear 6 are determined based on information for one cycle of the rotation waveform (torque waveform of the engine 1). Therefore, control by the command torque rTff is stopped for the duration of that one cycle.

[0080] With the above configuration, even if the operation of engine 1 fluctuates, the command torque rTff can be updated to a more appropriate value. As a result, the rattle noise between the first gear 5 and the second gear 6 can be suppressed over a long period of time. Furthermore, even with feedforward control, the rattle noise between the first gear 5 and the second gear 6 can be suppressed.

[0081] (5) Waveform deformation: In the above-described embodiment, the waveform of the command torque rTff for the motor 4 is a sinusoidal waveform. However, the waveform of the command torque rTff for the motor 4 is not limited to a sinusoidal waveform. For example, in the above-described embodiment, the control unit 20 may control the motor 4 so that the second gear waveform is a triangular wave.

[0082] A triangular wave is not limited to this, but for example, it can be a triangular wave in which the torque increases at the upper limit of the range of torque change that can be increased per unit time in motor 4, and decreases at the upper limit of the range of torque change that can be decreased per unit time in motor 4. In other words, in motor 4, the range of torque change that can be increased or decreased per unit time (torque rate) is generally limited. Therefore, in order to change the torque waveform of the torque output from motor 4 to the maximum extent possible within this range, a triangular wave is obtained in which the torque increases at the upper limit of the range of change and decreases at the upper limit of the range of change.

[0083] Figures 11A and 11B show the engine waveform (EG), first gear waveform, and second gear waveform for torque and rotational speed, respectively. Figure 11A also includes the waveform of the command torque rTff input to motor 4 (MG). In each figure, the waveforms are distinguished by the line thickness decreasing in the order of engine waveform, first gear waveform, second gear waveform, and motor 4 command torque rTff waveform.

[0084] In Figures 11A and 11B, it is assumed that the engine waveform is a sine wave. If the command torque rTff of motor 4 is set to a sine wave in accordance with this sine wave, the amplitude of the command torque rTff to motor 4 will be αTd. However, if the torque change exceeds the upper limit for a sine wave with amplitude αTd, it is not possible to set a sine wave with amplitude αTd as the command torque rTff (even if it is set as the command torque rTff, there will be limitations in practice).

[0085] The waveform (MG) of the command torque rTff input to motor 4 shown in Figure 11A represents a sine wave limited to a torque variation range. In a sine wave, the slope is large near the zero crossing (near phase 0 rad) and small near the maximum amplitude (e.g., near phase π / 2 rad). Therefore, the waveform limited to a torque variation range near the zero crossing changes with a considerably smaller amplitude near the maximum amplitude than the torque variation range. For this reason, even if a larger amplitude sine wave is required for the ideal command torque rTff, it is difficult to increase the amplitude of the sine wave when the torque variation range is limited.

[0086] Therefore, by using a triangular wave instead of a sine wave, it is possible to generate a command torque rTff with a larger amplitude. Figures 12A and 12B show the engine waveform (EG), first gear waveform, and second gear waveform for torque and rotational speed, respectively. However, in Figure 12A, the waveform of the command torque rTff input to motor 4 (MG) is a triangular wave. In Figures 12A and 12B, the lines are distinguished by decreasing thickness in the order of engine waveform, first gear waveform, second gear waveform, and command torque rTff waveform of motor 4.

[0087] The waveform of the command torque rTff (MG) shown in Figure 12A is a triangular wave in which the torque increases at the upper limit of the torque change range that can be increased per unit time in motor 4, and decreases at the upper limit of the torque change range that can be decreased per unit time in motor 4. In other words, it is a triangular wave in which the torque increases or decreases at the upper limit of the torque change range. This triangular wave is the upper limit waveform beyond which the torque cannot be made larger. Therefore, by using this triangular wave, it is possible to generate a waveform with the largest possible amplitude within the limit of the torque change range.

[0088] As shown in Figure 11B, the difference between the maximum rotational speed of the first gear waveform and the maximum rotational speed of the second gear waveform is Δ1. As shown in Figure 12B, the difference between the maximum rotational speed of the first gear waveform and the maximum rotational speed of the second gear waveform is Δ2. Comparing these differences, Δ1 > Δ2, and the difference is smaller in Figure 12, which uses a triangular wave. Therefore, it can be seen that the gear noise caused by the collision between the first gear 5 and the second gear 6 is suppressed.

[0089] As described above, when using a triangular wave, the control unit 20 can change the amplitude of the command torque rTff in the above embodiment to make it a triangular wave. The frequency can be the frequency freal determined from the engine waveform, etc., and the control start timing using the triangular wave can be determined based on the start timing determined from the engine waveform, etc., and delay compensation can be performed by delay amount D.

[0090] Furthermore, in the above-described embodiment, the control unit 20 may control the motor 4 so that the second gear waveform mimics the first gear waveform. That is, the engine waveform and the first gear waveform may be different from a sine wave. In this case, these waveforms may be identified in advance, and the waveform of the command torque rTff may be set to mimic those waveforms.

[0091] Figure 13A shows the engine waveform (EG) of a system using a certain engine 1, in terms of torque. Figure 13B shows the engine waveform (EG) and the first gear waveform of a system using a certain engine 1, in terms of rotational speed. Furthermore, Figures 13A and 13B assume that the second gear waveform, which corresponds to the waveform of the command torque rTff input to motor 4, is a sine wave. As a result of this torque, the rotational waveform in the second gear is also a sine wave. In each figure, the engine waveform, first gear waveform, and motor 4 waveform are distinguished by the line thickness decreasing in that order.

[0092] In Figures 13A and 13B, the engine waveform is not a sine wave. For the torque shown in Figure 13A, the waveform repeatedly increases sharply, then decreases sharply, and then slowly decreases. For the rotational speed shown in Figure 13B, the waveform repeatedly increases sharply, then decreases slowly, and then rapidly decreases. Reflecting the torque and rotational speed of engine 1, the rotational speed of the first gear 5, as the first gear waveform, is relatively close to the rotational speed of engine 1, and exhibits a waveform that increases sharply, then decreases slowly, and then rapidly decreases. Note that the rotational speed as the first gear waveform includes smaller fluctuations than the rotational speed as the engine waveform.

[0093] As shown in Figure 13A, if the amplitude of the torque waveform of the sinusoidal motor 4 is matched to the maximum amplitude of the torque waveform of engine 1, the minimum amplitude of the torque waveform of engine 1 and the torque waveform of motor 4 diverge significantly. Even if the amplitude of the torque waveform of the sinusoidal motor 4 is matched to the minimum amplitude of the torque waveform of engine 1, the two diverge significantly at the maximum amplitude.

[0094] Due to this waveform divergence, the rotational speed waveform shown in Figure 13B also diverges significantly. Since the rotational speed of the second gear 6 changes in roughly the same way as the rotational speed of the motor 4, the first gear waveform shown in Figure 13B diverges from the second gear waveform of the second gear 6 connected to the output shaft of the motor 4. For this reason, a gear-clapping noise may occur at the timing when the waveforms diverge.

[0095] Therefore, by controlling the motor 4 so that the second gear waveform mimics the first gear waveform instead of a sine wave, the gear noise can be suppressed. It is preferable that the waveforms mimicking each other are within the limit of the torque change range (torque rate) that can be increased or decreased per unit time. Figure 14A shows the engine waveform (EG) of a system using a certain engine 1 in terms of torque. Figure 14B shows the engine waveform (EG) and the first gear waveform of a system using a certain engine 1 in terms of rotational speed. Furthermore, Figures 14A and 14B assume that the waveform of the command torque rTff input to the motor 4 is a waveform that mimics the torque waveform of the engine 1. In other words, this embodiment assumes that the second gear waveform is a waveform similar to the waveform of the command torque rTff input to the motor 4, and the first gear waveform is a waveform similar to the torque waveform of the engine 1. In this embodiment, the motor 4 is controlled so that the second gear waveform, which corresponds to the command torque rTff input to the motor 4, resembles the torque waveform of the engine 1, thereby mimicking the waveform of the first gear. In each figure, the engine waveform, first gear waveform, and second gear waveform are distinguished by the lines becoming progressively lighter in thickness in that order.

[0096] The second gear waveform shown in Figure 14A is similar to the torque waveform of engine 1. Comparing Figures 13A and 13B with Figures 14A and 14B, it can be seen that using a command torque rTff with a waveform similar to the torque waveform of engine 1 results in closer rotational speed waveforms for the first gear and second gear than when a sine wave is used (Figures 13B and 14B). Therefore, it can be seen that using a command torque rTff with a waveform similar to the torque waveform of engine 1 suppresses the gear noise caused by the collision between the first gear 5 and the second gear 6.

[0097] As described above, when using a command torque rTff with a waveform similar to the torque waveform of engine 1, the control unit 20 generates the command torque rTff using a waveform stored in a memory (not shown). For example, the time-series change of the command torque rTff for one period at a reference amplitude is stored in memory beforehand, and the control unit 20 generates a waveform based on this one-period waveform, for example, using the same gain as α described above, with a frequency freal identified from the engine waveform, etc. The control start timing may be determined based on the start timing identified from the engine waveform, etc., and delay compensation can be performed by delay amount D. With the above configuration, gear noise can be suppressed more effectively than when controlling motor 4 using a sine wave.

[0098] (6) Other embodiments, etc.: The embodiments described above are merely examples for carrying out the present invention, and various other embodiments can be adopted. For example, a system in which gear noise is suppressed by controlling the motor so that the second gear waveform is in phase with the first gear waveform is not limited to the system shown in Figure 1.

[0099] Figure 15 shows an example of a system configuration for suppressing gear noise. In Figure 15, components that function similarly to those in Figure 1 are indicated by the same reference numerals. The configuration shown in Figure 15 differs from the configuration shown in Figure 1 in the gear configuration and the presence of a drive motor 10 connected to the gears. The engine 1 is connected to the input shaft 3a of the transmission 3 via a clutch damper 2, and the motor 4 is connected to the output shaft 3b of the transmission 3 via a first gear 5 and a second gear 6.

[0100] In the embodiment shown in Figure 15, the first gear 5 is a pinion gear, and the second gear 6 is a sun gear, configured to mesh with the ring gear 7. That is, the first gear 5, the second gear 6, and the ring gear 7 constitute a planetary gear mechanism. The ring gear 7 is connected to the drive motor 10 via gears 8 and 9. The rotation of gear 8 is transmitted to the wheels. The vehicle shown in Figure 15 is driven by the power of engine 1 and the drive motor 10. Furthermore, when regenerating energy is charged, motor 4 is used as a generator, and the electricity generated by the rotation of motor 4 is used to charge the battery. That is, the vehicle shown in Figure 15 is a split hybrid vehicle.

[0101] In the above configuration, the control unit 20 acquires the detection result of the crank angle sensor 11 attached to the engine 1 and outputs a command torque rTff based on the detection result. In this configuration, the control unit 20 can suppress the gear noise caused by the collision of the first gear 5 and the second gear 6 by performing the processing shown in Figure 3 and the various modifications described above. Of course, various modifications can be made in this embodiment. For example, the control start condition, which is determined to be satisfied or not in step S100, may be different from that in the above embodiment.

[0102] Figure 16 shows another example configuration of the system targeted for gear noise suppression. In Figure 16, components that function similarly to those in Figures 1 and 15 are indicated by the same reference numerals. The configuration shown in Figure 16 differs from the configuration shown in Figure 1 in the gear configuration and the presence of a drive motor 10 connected to the gears. The engine 1 is connected to the input shaft 3a of the transmission 3 via a clutch damper 2, and the motor 4 is connected to the output shaft 3b of the transmission 3 via a first gear 5 and a second gear 6.

[0103] In the embodiment shown in Figure 16, the first gear 5 is connected to gear 7' via clutch 2'. Gear 7' meshes with gear 8. Gear 8 meshes with gear 9, which is connected to the drive motor 10. The rotation of gear 8 is transmitted to the wheels. The vehicle shown in Figure 16 is driven by the power of engine 1 and the drive motor 10. Furthermore, when regenerating energy is charged, motor 4 is used as a generator, and the electricity generated by the rotation of motor 4 is used to charge the battery. In other words, the vehicle shown in Figure 16 is a series-parallel hybrid vehicle.

[0104] In the above configuration, the control unit 20 acquires the detection result of the crank angle sensor 11 attached to the engine 1 and outputs a command torque rTff based on the detection result. In this configuration, the control unit 20 can suppress the gear noise caused by the collision of the first gear 5 and the second gear 6 by performing the processing shown in Figure 3 and the various modifications described above. Of course, various modifications can be made in this embodiment. For example, the control start condition, which is determined to be satisfied or not in step S100, may be different from that in the above embodiment.

[0105] The engine only needs to be able to transmit rotational driving force to the transmission. Therefore, as in the embodiment described above, torque may be transmitted from the engine to the transmission via a clutch damper. Furthermore, detection of the engine waveform is not limited to detection based on the crank angle sensor, but may be acquired by various other sensors. For example, the engine waveform may be identified from the value detected by the throttle sensor. Also, since torque and rotational speed at the engine's output shaft can be expressed in a one-to-one relationship, detection of the engine waveform and detection of the engine's rotational speed can be considered equivalent.

[0106] The transmission only needs to be able to transmit the torque output from the engine to the first gear. The method of shifting gears in the transmission is not limited and may consist of various combinations of gears, shafts, clutches, etc., or it may include a planetary gear mechanism and a torque converter, or it may include a friction clutch. It may also include a belt and pulley. The torque source that inputs torque to the transmission is not limited to the engine and may be various devices. For example, it may be an electric motor.

[0107] The first gear only needs to be connected to the output shaft of the transmission. In other words, it just needs to be configured so that the torque output from the transmission is input to the first gear. The first gear is not limited to a single gear configuration, but may be composed of multiple gears. For example, part of a planetary gear mechanism may serve as the first gear.

[0108] The first gear waveform is a waveform corresponding to the torque input to the first gear, for example, the waveform of the torque acting on the first gear in accordance with the torque output from the transmission. The first gear waveform may be identified based on the output of a sensor provided on the engine, as in the configuration described above, or it may be identified based on the output of a sensor provided on each shaft of the transmission, for example, on the output shaft. Since various shafts may exist in the transmission, various shafts may be output shafts, but for example, the shaft that directly transmits torque to the first gear may be an output shaft.

[0109] A motor can be any device that rotates using electricity. That is, it must be capable of controlling its output torque using electricity supplied based on a control unit. Of course, the motor may also generate electricity through its rotation.

[0110] The second gear is connected to the output shaft of the motor and should mesh with the first gear. In other words, it should be configured so that the torque output from the motor is input to the second gear. The second gear waveform is the waveform of the torque acting on the second gear in accordance with the torque input to the second gear, and is, for example, the waveform of the torque output from the motor. The second gear waveform is generated by the control unit, for example, by torque control of the motor. The second gear is not limited to a single gear configuration, but may be composed of multiple gears.

[0111] The control unit only needs to be able to control the motor so that the second gear waveform, which corresponds to the torque waveform input to the second gear, is in phase with the first gear waveform, based on the first gear waveform, which corresponds to the torque waveform input to the first gear. In other words, it is sufficient that the teeth of the first gear and the teeth of the second gear rotate in synchronously, preventing one from rotating faster than the other and preventing the teeth from colliding. Such a configuration can be realized by various configurations other than the one described above, in which the rotation angle of the transmission and the rotation angle of the motor, which is obtained by multiplying the radius ratio of the first gear and the second gear, coincide, and the time derivatives of each rotation angle coincide.

[0112] However, when controlling the motor, the control unit detects the engine waveform, which is the torque waveform output from the engine, and applies a bandpass filter to the engine waveform that allows the frequency band of vibrations caused by engine explosions to pass through, thereby identifying the first gear waveform that is input from the engine to the first gear via the transmission. In other words, the vibrations that are the focus of eliminating gear noise are limited to vibrations caused by engine explosions. With this configuration, gear noise caused by vibrations from engine explosions can be effectively suppressed.

[0113] Vibrations caused by an explosion can be any vibrations that occur in conjunction with the rotation caused by the engine explosion, and various types of vibrations are possible. Therefore, in addition to vibrations caused by the up-and-down motion of the piston accompanying the engine explosion (primary vibrations) as in the embodiment described above, various other vibrations can be considered as causes of the rattle noise, and their frequencies can be used as the passband frequencies of the bandpass filter. For example, the frequency band determined by estimating and pre-identifying vibration components that affect NVH (Noise, Vibration, Harshness) from the engine speed and the vehicle condition may be used as the passband frequency band of the bandpass filter.

[0114] In the above embodiment, to determine the motor control start timing by comparing the engine waveform with a bandpass filter applied to a predetermined value, the predetermined value is set to 0, and the timing at which the engine waveform with the bandpass filter applied crosses 0 is identified. However, the predetermined value is not limited to 0, and the engine waveform with the bandpass filter applied and the predetermined value may be compared using various methods. For example, it may be the timing at which the direction of signal change changes, such as the peak of a sine wave (the point at which the sign of the derivative changes), or various statistical processing may be performed.

[0115] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but should be in the broadest scope according to the technical idea defined by the claims. [Explanation of Symbols]

[0116] 1...Engine, 2...Clutch / Damper, 3...Transmission, 3a...Input Shaft, 3b...Output Shaft, 4...Motor, 5...First Gear, 6...Second Gear, 7...Ring Gear, 7'...Gear, 8...Gear, 9...Gear, 10...Drive Motor, 11...Crank Angle Sensor, 20...Control Unit, 21...Control Necessity Determination Unit, 22...Frequency Calculation Unit, 23...Bandpass Filter, 24...Waveform Analysis Unit, 25...Command Torque Calculation Unit, 26...Phase Compensation Unit

Claims

1. The engine and A transmission through which the rotational driving force of the aforementioned engine is transmitted, A first gear connected to the output shaft of the aforementioned transmission, Motor and, A second gear is connected to the output shaft of the motor and meshes with the first gear, The system includes a control unit that controls the motor based on a first gear waveform corresponding to the torque waveform input to the first gear, such that the second gear waveform corresponding to the torque waveform input to the second gear is in phase with the first gear waveform, The control unit detects an engine waveform, which is the torque waveform output from the engine, and applies a bandpass filter to the engine waveform that allows the frequency band of vibrations caused by the engine's explosion to pass through, thereby identifying the first gear waveform that is input from the engine to the first gear via the transmission. Motor control device.

2. The vibration caused by the explosion of the engine is the primary vibration of the engine. The motor control device according to claim 1.

3. The control unit, The engine waveform with the bandpass filter applied is compared with a predetermined value to determine the motor control start timing. A motor control device according to claim 1 or claim 2.

4. The control unit, The motor is controlled by compensating for the delay that occurs between the detection of the engine waveform of the engine and the input of the second gear waveform. A motor control device according to claim 1 or claim 2.

5. The control unit, The transfer function of the bandpass filter is changed according to the frequency of the engine waveform. A motor control device according to claim 1 or claim 2.

6. The control unit, The motor is controlled based on a common command value until the change in the engine waveform of the engine exceeds a certain standard. If the change in the engine waveform exceeds the standard, the command value is updated. A motor control device according to claim 1 or claim 2.

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