Generator control method and generator control device

Abstract

A generator control method of controlling a generator driven by an engine via a crankshaft of the engine, determining whether the engine is stopped, operating the generator to adjust a crankshaft position of the crankshaft to a prescribed target stop position if it is determined that the engine is stopped, determining whether an in-cylinder pressure of the engine is greater than or equal to a prescribed threshold value, and continuing to operate the generator to maintain the crankshaft position at the target stop position in the case where the in-cylinder pressure is greater than or equal to the threshold value.

Description

Technical Field

[0001] This invention relates to a generator control method and a generator control device. Background Technology

[0002] JP2018-002107A discloses a vehicle that, when the engine is stopped, performs crankshaft position control by applying braking force to the crankshaft of the engine using an alternator (generator) to stop the crankshaft at a desired target stopping position. In this crankshaft position control, the alternator (generator) is controlled to generate braking torque for the crankshaft, thereby controlling the crankshaft position. Summary of the Invention

[0003] However, in the above crankshaft position control, there is a problem: the crankshaft position deviates from the target stopping position due to the reaction force caused by the cylinder pressure remaining in the cylinder after the engine stops, which reduces the positioning accuracy of the crankshaft.

[0004] Therefore, the object of the present invention is to provide a generator control method and generator control device that can more reliably maintain the crankshaft position at the target stopping position after the engine has stopped.

[0005] According to one aspect of the present invention, a generator control method is provided for controlling a generator driven by an engine via the engine crankshaft. In this generator control method, it is determined whether the engine has stopped; if the engine has stopped, the generator is operated to adjust the crankshaft position to a predetermined target stopping position. Furthermore, it is determined whether the engine cylinder pressure is greater than or equal to a predetermined threshold; if the cylinder pressure is greater than or equal to the threshold, the generator is continuously operated to maintain the crankshaft position at the target stopping position. Attached Figure Description

[0006] Figure 1 This is a block diagram illustrating the main structure of an electric vehicle that performs the generator control method according to each implementation method.

[0007] Figure 2 It is a block diagram representing the overall structure of the generator system.

[0008] Figure 3 This is a block diagram showing the main structure of the generator system according to the first embodiment.

[0009] Figure 4 This is a block diagram showing the main structure of the generator system according to the second embodiment.

[0010] Figure 5 This is a block diagram showing the essential structure of the generator system according to the third embodiment.

[0011] Figure 6 This is a block diagram showing the essential structure of the generator system according to the fourth embodiment.

[0012] Figure 7 It is a timing diagram representing the control results of proportional control.

[0013] Figure 8 This is a timing diagram illustrating the control results of the embodiment. Detailed Implementation

[0014] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0015] [First Implementation]

[0016] Figure 1 This is an explanatory diagram showing the general structure of an electric vehicle 100. (For example...) Figure 1 As shown, the electric vehicle 100 is a vehicle powered by electricity from the battery 10, and includes a drive motor 11 and a power generation device 12. In particular, in this embodiment, an example of an electric vehicle 100 configured as a so-called series hybrid vehicle will be described.

[0017] Battery 10 stores electricity for driving various parts of electric vehicle 100. Battery 10 is rechargeable. In this embodiment, battery 10 is charged at least by electricity generated by generator 12. In this embodiment, battery 10 is a DC power source. The DC voltage output by battery 10 (battery voltage V) dc It can be detected by sensors, etc., not shown.

[0018] The drive motor 11 is an electric motor (specifically a three-phase AC motor) that functions as the driving source for the electric vehicle 100. The drive motor 11 is connected to the battery 10 via the drive inverter 16.

[0019] The drive motor 11 (more specifically, the output shaft of the drive motor 11) is connected to the drive wheel 15 via a transmission mechanism such as a reducer 13 and a drive shaft 14. Therefore, during power operation (e.g., acceleration of the electric vehicle 100), the drive motor 11 receives power from the battery 10 and transmits driving force to the drive wheel 15 via the reducer 13. On the other hand, during regenerative operation (e.g., deceleration of the electric vehicle 100), the drive motor 11 applies regenerative braking force to the drive wheel 15, regenerating the electrical energy obtained by applying this regenerative braking force back to the battery 10.

[0020] When the drive motor 11 is in power operation, the drive inverter 16 converts the DC power output from the battery 10 into AC power and supplies it to the drive motor 11. In addition, when the drive motor 11 is in regenerative operation, the drive inverter 16 converts the AC power generated in the drive motor 11 into DC power.

[0021] Engine 17 is a so-called internal combustion engine, which functions as a power source for the power generation device 12. Furthermore, parameters related to the engine 17's speed and operating status can be appropriately detected by sensors (not shown).

[0022] The generator (generator-generator) 18 is configured as an electric motor (particularly a three-phase AC motor) consisting of a rotor connected to the crankshaft of the engine 17 and a stator equipped with magnets, windings, etc. The generator 18 is connected to the battery 10 via a generator inverter 20. Furthermore, during regenerative operation (power generation), the generator 18 applies a regenerative braking force (braking torque) to the crankshaft of the engine 17, regenerating the electrical energy obtained by applying this regenerative braking force to the battery 10.

[0023] During the regenerative operation of the generator 18, the generator inverter 20 converts the AC power generated in the generator 18 into DC power. Conversely, during the power operation of the generator 18, the generator inverter 20 converts the DC power output from the battery 10 into AC power and supplies it to the generator 18. Thus, when the engine 17 starts, the generator 18 is activated for power operation, causing the crankshaft of the engine 17 to rotate. Furthermore, depending on the situation, the generator 18 is activated for power operation while the engine 17 idles (motor operation), thereby also consuming power from the battery 10.

[0024] Furthermore, the measured value of the current flowing in the U phase of generator 18 will be referred to as the U-phase current I. u The measured value of the current flowing in phase V is called the phase V current I. v The measured value of the current flowing in phase W is called the phase W current I. w Additionally, the measured value of the d-axis current of generator 18 is referred to as the d-axis current I. d The detected value of the q-axis current is called the q-axis current I. q Additionally, sometimes the d-axis current I of generator 18 is... d and q-axis current I q Collectively referred to as dq-axis current I d I q .

[0025] In addition, the electric vehicle 100 includes a system controller 21, a drive motor controller 22, a battery controller 23, a generator controller 24, and an engine controller 25 as various control devices. Furthermore, in this embodiment, the system controller 21 includes a power generation control unit 26.

[0026] System controller 21 is a higher-level control unit that uses vehicle information to uniformly control all parts of the electric vehicle 100. Here, vehicle information refers to parameters representing the operational states of each part constituting the electric vehicle 100. Vehicle information includes, for example, parameters based on the driver's accelerator pedal input (accelerator opening Apo), vehicle speed V, and the gradient of the road surface on which the electric vehicle 100 travels. Vehicle information can be defined based on detection values ​​from various sensors (not shown).

[0027] Based on the aforementioned vehicle information, and the SOC (State of Charge) of the battery 10, the input power, the output power, and the target generated power (described later) input from the battery controller 23, the system controller 21 calculates the command value of the output torque of the drive motor 11 (hereinafter referred to as the "drive motor torque command value"). The system controller 21 outputs the calculated drive motor torque command value to the drive motor controller 22.

[0028] In addition, the system controller 21 (especially the power generation control unit 26) calculates the target power generation of the generator 18 based on the aforementioned vehicle information, as well as the SOC, input power and output power of the battery 10 input from the battery controller 23.

[0029] Furthermore, the power generation control unit 26 controls the operating points of the engine 17 and the generator 18 based on the target power generation. Specifically, the power generation control unit 26 adjusts the speed command value ω according to the target power generation. g ＊ and engine torque command value T E ＊ Perform the calculation.

[0030] Here, the speed command value ω g ＊ This refers to the command value regarding the rotational speed (angular velocity) that generator 18 should maintain in order to generate the target amount of electricity. Additionally, the engine torque command value T... E ＊ It is a command value regarding the torque that the engine 17 should output in order to generate electricity using the power generation device 12.

[0031] Furthermore, the power generation control unit 26 will calculate the speed command value ω g ＊ and engine torque command value TE ＊ Outputs are sent to generator controller 24 and engine controller 25 respectively.

[0032] The drive motor controller 22, battery controller 23, generator controller 24, and engine controller 25 are lower-level control units that individually control each part of the electric vehicle 100 based on the instructions of the system controller 21.

[0033] The drive motor controller 22 switches the drive inverter 16 on and off based on the drive motor torque command value and the speed, voltage and other states of the drive motor 11.

[0034] The battery controller 23 calculates the temperature, voltage, current, internal resistance, state of charge (SOC), input power, and output power of the battery 10 by referring to the detection values ​​of sensors (not shown). Furthermore, the battery controller 23 outputs the calculated SOC, input power, and output power to the system controller 21.

[0035] The generator controller 24 controls the operating point of the generator 18. More specifically, the generator controller 24 receives the speed command value ω from the system controller 21. g ＊ The generator inverter 20 is switched on and off using the speed sensor 37 as input. Specifically, regarding the generator controller 24 of this embodiment, the speed sensor 37 (see reference 20) is used to control the switching of the generator inverter 20. Figure 2 The measured speed of generator 18 (hereinafter referred to as "speed measurement value ω") is obtained. g The generator controller 24 performs feedback speed control to control the speed of the generator 18. The structure of the generator controller 24 will be described in detail later.

[0036] The engine controller 25 controls the operating point of the engine 17. More specifically, the engine controller 25 controls the engine torque command value T obtained from the system controller 21. E ＊ The various actuators (throttle valve, igniter, and fuel injector, etc.) of the engine 17 are operated as inputs. Thus, the engine 17 operates to generate electricity in order to achieve the aforementioned objective. Furthermore, if the engine controller 25 of this embodiment detects a stop request (stop command for the engine 17) corresponding to the operation of the occupants of the electric vehicle 100, instructions from the system controller 21, etc., it executes engine 17 stop processing (stopping ignition processing and fuel cut-off, etc.) and generates an engine stop request flag Enf. Moreover, the engine controller 25 outputs the engine stop request flag Enf to the generator controller 24 via the system controller 21.

[0037] The system controller 21, drive motor controller 22, battery controller 23, generator controller 24, and engine controller 25 described above are each composed of one or more computer hardware components, including a central processing unit (CPU), random access memory (RAM), and input / output interfaces (I / O interfaces). Furthermore, each controller is programmed to perform various controls as described in this embodiment. Additionally, two or more of the aforementioned controllers can be composed of a single piece of computer hardware.

[0038] The structure of the system (hereinafter referred to as "generator system S") consisting of generator 18, generator inverter 20 and generator controller 24 will be described in detail below, as well as the processing performed by generator system S.

[0039] Figure 2 This is a block diagram showing the structure of the generator system S. As shown in the figure, the generator controller 24, which functions as the control device for the generator system S, includes a control switching determination unit 29, an angle control unit 30, a speed control unit 31, a current command value calculation unit 32, a current control unit 33, a non-interference control unit 34, a current converter 35, and a voltage converter 36.

[0040] The control switching determination unit 29 determines the cylinder pressure P of the engine 17. eng As input, a control maintenance flag Cf is generated to indicate the maintenance and termination of crankshaft position control. Here, the crankshaft position control in this embodiment is represented as follows: starting from the detection of a stop command for engine 17 (engine stop request flag Enf is ON), the operation point of generator 18 is operated in such a way that the crankshaft position (crankshaft position) of engine 17 approaches a predetermined target stop position.

[0041] Specifically, the in-cylinder pressure P of engine 17 eng Greater than or equal to the specified threshold P ength In this case, the control switching determination unit 29 sets the control maintenance flag Cf, which instructs the execution of crankshaft position control, to ON. On the other hand, when the cylinder pressure P... eng Less than threshold P ength In the event of this, the control switching determination unit 29 sets the control maintenance flag Cf to OFF.

[0042] Here, the threshold P ength The appropriate cylinder pressure P is defined from the perspective of determining whether a reaction force is generated that causes the crankshaft position to deviate relative to the crankshaft. eng The value of the cylinder pressure. Furthermore, when the engine 17 consists of multiple cylinders, the control switching determination unit 29 uses the maximum value among the cylinder pressures of the multiple cylinders as the "cylinder pressure P". eng"And perform the comparison with the threshold P" ength The control switch determination unit 29 compares the magnitudes of the control flags and sets the control maintenance flag Cf to ON or OFF based on the result. Furthermore, the control switch determination unit 29 outputs the set control maintenance flag Cf to the control maintenance flag reference unit 44.

[0043] The angle control unit 30 transmits the angle command value θ of the generator 18. g ＊ The angle control speed command value ω is used as input. θg ＊ Perform the calculation. Additionally, the angle command value θ... g ＊ This is the command value for the generator's angle (mechanical or electrical angle) 18, specified based on the target power output. Angle command value θ g ＊ For example, by setting the speed command value ω g ＊ It is obtained by integration. Additionally, the angle control speed command value ω... θg ＊ It is the command value of the generator speed specified in crankshaft position control based on the difference between the crankshaft position and the target stop position.

[0044] The speed control unit 31 refers to the control maintenance flag Cf and bases its speed control on the speed command value ω. g ＊ and the angle control speed command value ω input from the angle control unit 30 θg ＊ Either of these factors is ultimately used to specify the output torque of generator 18 (hereinafter also referred to as "generator torque T"). ω The final torque command value T) ω ＊＊ The calculation is performed. Furthermore, the structure of the speed control unit 31 will be described in detail later.

[0045] The current command value calculation unit 32 calculates the final torque command value T from the speed control unit 31. ω ＊＊ The speed detection value ω from the speed sensor 37 g and battery voltage V dc The d-axis current command value I of generator 18 is input. d ＊ and q-axis current command value I q ＊ The calculation is performed. Furthermore, the current command value calculation unit 32 calculates the d-axis current command value I. d ＊ and q-axis current command value I q ＊ Output to current control unit 33.

[0046] The current control unit 33 utilizes the d-axis current command value I d ＊ q-axis current command value I q ＊ d-axis current I d q-axis current I q and the speed detection value ω g The d-axis voltage command value V for generator 18 d ＊ and the q-axis voltage command value V q ＊ Perform the calculation. Additionally, the d-axis voltage command value V... d ＊ and the q-axis voltage command value V q ＊ The non-interference control voltage (described later) is subtracted by subtraction units 38 and 39, respectively. Furthermore, the final d-axis voltage command value V′ obtained through this subtraction operation is... d ＊ and the final voltage command value V′ on the q-axis q ＊ The output is sent to voltage converter 36.

[0047] Non-interference control unit 34 utilizes d-axis current I d and q-axis current I q The non-interference control voltage used to reduce the voltage drop caused by interference between the d-axis and q-axis is calculated.

[0048] Current converter 35 converts the three-phase current I u I v I w Transformed into dq-axis current I d I q Three-phase current I u I v I w The current is detected by a current sensor 50 located between the generator inverter 20 and the generator 18. Furthermore, in this embodiment, the U-phase current I is detected using the current sensor 50. u and V-phase current I v The current converter 35 determines the phase current I of phase W through calculation. w Furthermore, as mentioned earlier, the current converter 35 will calculate the dq-axis current I. d I q The current command value is output to the current command value calculation unit 32 and the non-interference control unit 34.

[0049] Voltage converter 36 based on the final voltage command value V′ of the dq axis d＊ V′ q ＊ Voltage command values ​​for each phase of UVW (three-phase voltage command values) V u ＊ V v ＊ V w ＊ The calculation is performed. The voltage converter 36 converts the calculated three-phase voltage command value V... u ＊ V v ＊ V w ＊ Output to generator inverter 20.

[0050] The generator inverter 20 converts the three-phase voltage command value V u ＊ V v ＊ V w ＊ As input, a U-phase voltage V is applied to each phase of the generator 18. u Phase V voltage V v and W-phase voltage V w Therefore, generator 18 performs the action at the desired operating point.

[0051] The following is a more detailed explanation of the key components of the generator system S, centered on the processing of the angle control unit 30 and the speed control unit 31.

[0052] Figure 3 This is a block diagram showing the main structure of the generator system S. As shown in the figure, the angle control unit 30, for example, controls the angle detection value θ via P. g With angle command value θ g ＊ The angle control speed command value ω is calculated by multiplying the deviation by the gain ag. θg ＊ .

[0053] Here, the angle detection value θ g This is the detected value of the rotation angle (mechanical angle) of the current generator 18. Angle detection value θ g The speed detection value ω detected by the speed sensor 37 is analyzed. g It is obtained through integration. Additionally, the angle command value θ... g ＊ The rotation angle of the generator 18 is specified as corresponding to the target stop position mentioned above in crankshaft position control. That is, the angle command value θ. g ＊It is defined as the rotation angle achieved by the output shaft of the generator 18 connected to the crankshaft when the crankshaft is in the target stop position.

[0054] On the other hand, the speed control unit 31 has a stop command flag reference unit 40, a model matching compensation unit 41, and an external disturbance observer 42.

[0055] Stop command flag reference unit 40 refers to engine stop request flag Enf and sets the speed command value ω g ＊ and the angle control speed command value ω θg ＊ Either of these values ​​is output to the model matching compensation unit 41. More specifically, when the engine stop request flag Enf is OFF, the stop command flag reference unit 40 outputs the engine speed command value ω. g ＊ The output (the command value corresponding to the target generated power) will be the angle control speed command value ω when the engine stop request flag Enf is ON. θg ＊ (Command value for crankshaft position control) output. Furthermore, for the sake of simplicity, the explanation of the following processes will focus on the output of the angle control speed command value ω for crankshaft position control. θg ＊ The output will be explained accordingly.

[0056] Model matching compensation unit 41, for example, uses PI control to adjust the speed detection value ω. g Follow-up angle control speed command value ω θg ＊ The first target torque value T ω1 ＊ The calculation is performed. In particular, the model matching compensation unit 41 has a first model matching gain multiplication operation unit 51, a model matching filter 52, a subtraction operation unit 53, and a second model matching gain multiplication operation unit 54.

[0057] The first model matching gain multiplication operation unit 51 matches the angle control speed command value ω. θg ＊ Multiply by the first model matching gain gc. Using the design value J′ of the combined inertia J of generator 18 and engine 17 calculated for the generator shaft, the design value C′ of the viscous friction coefficient, and the time constant T of the target response... m The matching gain gc of the first model is represented by the following equation (1).

[0058] [Mathematical Expression 1]

[0059]

[0060] Furthermore, the design values ​​for the total inertia J′ and the viscous friction coefficient C′ are set to be equivalent to the characteristics of the actual controlled object. In principle, it is preferable to set the time constant T... m The specification is to make the model matching compensation unit 41 respond as sensitively as possible without compromising control stability.

[0061] Model matching filter 52 is for the speed detection value ω fed back to model matching compensation unit 41. g The implemented filter. The model matched filter 52 is, for example, a low-pass filter, whose transfer characteristic H is represented by the following equation (2). mm (s) represents the Laplace operator.

[0062] [Mathematical Expression 2]

[0063]

[0064] Subtraction unit 53 multiplies the rotational speed command value ω by the first model matching gain gc. g ＊ (i.e., gc·ω) g ＊ Subtract the speed detection value ω processed by the model matched filter 52 g (i.e. H) mm (s)·ω g The result of the subtraction operation unit 53 is input to the second model matching gain multiplication operation unit 54.

[0065] The second model matching gain multiplication unit 54 multiplies the output of the subtraction unit 53 by the second model matching gain cp. The second model matching gain cp is represented by the following equation (3).

[0066] [Mathematical Expression 3]

[0067]

[0068] The model matching compensation unit 41 uses the output of the second model matching gain multiplication operation unit 54 as the first torque target value T. ω1 ＊ The output is then sent to the torque command value calculation unit 43. As described above, the first torque target value T ω1 ＊ The generator torque T determined by model matching ω The target value.

[0069] External disturbance observer 42 will display the basic torque command value T ω ＊ and the speed detection value ω gAs input, the second torque target value T is the estimated external disturbance torque corresponding to the control system model of engine 17 and generator 18. ω2 ＊ Perform the calculation.

[0070] In addition, the basic torque command value T ω ＊ In crankshaft position control, the external disturbance torque T is taken into account. d The generator torque T is specified based on the consideration of the influence of the crankshaft position and the viewpoint of bringing the crankshaft position close to the target stopping position. ω The basic command value. Additionally, the external disturbance torque T d This is the input torque component from engine 17 (more specifically, crankshaft) to generator 18, caused by factors such as the compression reaction force of engine 17, combustion torque pulsation, and abnormal combustion. That is, the external disturbance torque T. d The cylinder pressure P of engine 17 eng Strong correlation.

[0071] In particular, in this embodiment, the external interference observer 42 has a first external interference observation filter 56, a second external interference observation filter 57, and a subtraction operation unit 58.

[0072] The first external disturbance observation filter 56 measures the basic torque command value T. ω ＊ Applying a low-pass filter H(s) as expressed by equation (4) below to the second torque target value T ω2＊ The first item (the first element) T ω2a ＊ Perform the calculation.

[0073] [Mathematical Expression 4]

[0074]

[0075] In addition, the "T" in the formula h " is the time constant of the external disturbance observer 42, which is appropriately specified. That is, the first term T" ω2a ＊ Equivalent to based on the basic torque command value T ω ＊ The obtained estimated value of actual torque does not include external disturbance components.

[0076] The second external interference observation filter 57 measures the rotational speed detection value ω. g Applying the filter H(s) / Gp′(s) given by the ratio of the low-pass filter H(s) and the transfer characteristic Gp′(s) to the target torque value T constitutes the second torque. ω2 ＊The second item (the second element) T ω2b ＊ The calculation is performed. In addition, the transmission characteristic Gp′(s) is a model of the transmission characteristics of the generator system S from torque input to speed, and is represented by the following equation (5).

[0077] [Mathematical Expression 5]

[0078]

[0079] That is, the second term T ω2b ＊ This is equivalent to the speed detection value ω g The estimated actual torque value, including external disturbance components, is obtained by applying the inverse system from torque input to speed.

[0080] Subtraction unit 58 performs subtraction from the first term T ω2a ＊ Subtract the second term T ω2b ＊ And for the second torque target value T ω2 ＊ The calculation is performed. The subtraction unit 58 calculates the second torque target value T. ω2 ＊ Output to torque command value calculation unit 43.

[0081] The torque command value calculation unit 43 calculates the first torque target value T from the model matching compensation unit 41. ω1 ＊ The second torque target value T is fed back from the external disturbance observer 42. ω2 ＊ Regarding the basic torque command value T ω ＊ The calculation is performed. In this embodiment, the torque command value calculation unit 43 is a subtraction operator, which calculates the torque command value from the first torque target value T. ω1 ＊ Subtract the second torque target value T ω2 ＊ Regarding the basic torque command value T ω ＊ The calculation is performed. Furthermore, the torque command value calculation unit 43 calculates the basic torque command value T. ω ＊ Output to control maintenance flag reference unit 44.

[0082] The control maintenance flag reference unit 44 refers to the control maintenance flag Cf from the control switching determination unit 29 and sets the basic torque command value T. ω ＊And either 0 or 0. More specifically, the control holding flag reference unit 44, when the control holding flag Cf is ON (when the cylinder pressure P... eng Greater than or equal to threshold P ength In the case of) the basic torque command value T ω ＊ Output, when the control holding flag Cf is OFF (at cylinder pressure P) eng Less than threshold P ength In the case of (the situation), 0 will be output.

[0083] The adder 45 is used to indicate the presence of external disturbance torque T on the output value of the control holding flag reference unit 44. d The structure of the influence.

[0084] Furthermore, the controlled object α refers to all control elements after the speed control unit 31 in the generator system S, namely the current command value calculation unit 32, the current control unit 33, the non-interference control unit 34, the current converter 35, the voltage converter 36, the generator inverter 20, and the generator 18.

[0085] Specifically, the control object α can be represented by the transfer function of the following equation (6) using the total inertia J of the generator 18 and engine 17 calculated for the generator shaft and the viscous friction coefficient C.

[0086] [Mathematical Expression 6]

[0087]

[0088] Furthermore, the speed detection value ω output from the controlled object α... g Adding the external disturbance speed ω detected / estimated by a detection / estimation device not shown d The value after addition is fed back to the model matching compensation unit 41. Furthermore, the value ω of the rotational speed detection is used to... g The angle detection value θ obtained by integration g Feedback is sent to the angle control unit 30.

[0089] According to the above control logic, the cylinder pressure P of engine 17 eng Greater than or equal to threshold P ength In this case, the final torque command value T ω ＊＊ (generator torque T) ω It is specified as being related to the angle command value θ. g ＊ The deviation specified angle detection value θ g Angle control speed command value ω θg ＊ The corresponding basic torque command value Tω ＊ and external disturbance torque T d The sum of these. Therefore, the generator 18 performs the action in a manner that brings the crankshaft position close to the target stopping position. In particular, in this case, even if the crankshaft position reaches the target stopping position (becoming θ), g =θ g ＊ The basic torque command value T ω ＊ When the torque of the generator becomes zero, the generator torque T ω It will also continue to work with the residual cylinder pressure P eng Corresponding external disturbance torque T d Output (maintain crankshaft position control).

[0090] On the other hand, the cylinder pressure P eng Less than threshold P ength Under these conditions, the generator torque T ω Set to the external disturbance torque T d The same. Therefore, if the crankshaft position reaches the target stop position, causing the cylinder pressure P of engine 17 to... eng If the external disturbance torque T is reduced by a value greater than or equal to a constant value, then... d (generator torque T) ω The position of the crankshaft changes to approximately zero, ending crankshaft position control.

[0091] The structure and effects of the generator control method of this embodiment described above will be explained in detail.

[0092] In this embodiment, a generator control method is provided for controlling a generator 18 driven by an engine 17 via the crankshaft of the engine 17. Regarding this generator control method, it is determined whether the engine 17 has stopped. If it is determined that the engine 17 has stopped (if it is determined that the engine stop request flag Enf is ON), the generator 18 is operated to adjust the crankshaft position to a predetermined target stop position. Additionally, the cylinder pressure P of the engine 17 is determined. eng Is it greater than or equal to the specified threshold P? ength (Control and maintenance flag reference unit 44), the cylinder pressure P eng Greater than or equal to threshold P ength In this case, the generator 18 is continuously operated and the crankshaft position is maintained at the target stop position.

[0093] Therefore, the pressure P inside the cylinder engWhen the crankshaft position is at or above a constant value, the generator 18 is continuously operated (crankshaft position control) to maintain the crankshaft position at the target stop position even after the crankshaft position reaches the target stop position. Therefore, crankshaft position deviation caused by residual pressure in the cylinders after the engine 17 is stopped can be suppressed. In other words, the crankshaft position can be maintained at the target stop position more reliably after the engine stops.

[0094] Furthermore, in this embodiment, the example described is that the generator controller 24 determines whether the engine 17 has stopped by referring to the engine stop request flag Enf generated by the engine controller 25. However, it is not limited to this; the logic of determining whether the engine 17 has stopped by referring to the detected values ​​of the rotational speed of the generator 18 and / or the engine 17 may also be used.

[0095] Furthermore, in this embodiment, the external disturbance torque T, which is equivalent to the external disturbance input to the generator 18, is obtained. d The basic torque command value T of generator 18 is based on the difference between the crankshaft position and the target stopping position. ω ＊ Calculations are performed (model matching compensation unit 41 and torque command value calculation unit 43). Furthermore, when the cylinder pressure Peng is greater than or equal to the threshold P... ength In the case of, based on the basic torque command value T ω ＊ and external disturbance torque T d The generator torque T, which is defined as the output torque of generator 18, is... ω (Control and maintain flag reference unit 44 and adder 45).

[0096] Therefore, the pressure P inside the cylinder eng When the value is higher than or equal to a constant value, the generator torque T can be specified in a way that brings the crankshaft position close to the target stopping position. ω On the other hand, even if the crankshaft position reaches the target stopping position (even if the basic torque command value T... ω ＊ Even if the generator torque T is reduced to zero, it can still reduce the generator torque T to zero. ω Adjusted to be equivalent to the input external disturbance torque T d The crankshaft position is maintained at the target stopping position. That is, the cylinder pressure P is achieved. eng Greater than or equal to threshold P ength In this case, more specific control logic is used to maintain the crankshaft position at the target stop position.

[0097] Furthermore, in this embodiment, the rotation angle detection value (angle detection value θ) of the generator 18 is used as the basis for the measurement. gThe crankshaft position is estimated, and the rotation angle command value (angle command value θ) of the generator 18 corresponding to the target stopping position is specified. g ＊ Furthermore, the difference between the crankshaft position and the target stopping position is defined as the angle detection value θ. g With angle command value θ g ＊ Deviation (angle control unit 30).

[0098] Therefore, crankshaft position control can be performed using the parameters in the control system of generator 18. That is, it is possible to achieve crankshaft position control without using parameters (crankshaft angle θ) equivalent to those in the control system of engine 17. e The control logic that can execute crankshaft position control is based on the detected values, etc.

[0099] Furthermore, in this embodiment, the angle detection value θ is made so that... g Follow angle command value θ g ＊ The method for determining the first torque target value T of generator 18 ω1 ＊ Calculations are performed (angle control unit 30 and model matching compensation unit 41). Furthermore, the rotational speed ω of the generator 18 is detected using the external disturbance observer 42. g Processing is performed on the second torque target value T, which is the estimated value of the external disturbance torque corresponding to the control system model. ω2 ＊ Perform calculations (external disturbance observer 42).

[0100] Moreover, the pressure P inside the cylinder eng Greater than or equal to threshold P ength In this case, the generator torque T ω Set as the basic torque command value T ω ＊ On the other hand, the cylinder pressure P eng Less than threshold P ength In this case, the generator torque T ω Set to the external disturbance torque T d Same as (control maintenance flag reference 44).

[0101] This achieves the function of pressing P in the cylinder. eng When the crankshaft position is adjusted to the target stop position at a value greater than or equal to a constant value, and the cylinder pressure P is... eng When the value is less than or equal to a constant value, more specific control logic for crankshaft position control is appropriately implemented.

[0102] Furthermore, in this embodiment, a generator controller 24 is provided that functions as a generator control device suitable for executing the above-described generator control method.

[0103] The generator controller 24 includes: a stop determination unit that determines whether the engine 17 has stopped; a control unit (41, 42, 43, 45) that, if it determines that the engine 17 has stopped (if the engine stop request flag Enf is ON), operates the generator 18 to adjust the crankshaft position to a predetermined target stop position; and a cylinder pressure determination unit (control maintenance flag reference unit 44) that determines the cylinder pressure P of the engine 17. eng Is it greater than or equal to the specified threshold P? ength ; and the control and maintenance unit (adder 45), which controls the cylinder pressure P eng Greater than or equal to threshold P ength In this case, it continues to operate the generator 18 to maintain the crankshaft position at the target stop position.

[0104] [Second Implementation]

[0105] The second embodiment will now be described. Furthermore, elements identical to those in the first embodiment will be labeled with the same reference numerals and their descriptions will be omitted.

[0106] Figure 4 This is a block diagram showing the main structure of the generator system S according to this embodiment. As shown, the generator system S of this embodiment has a cylinder pressure P for the engine 17. eng The cylinder pressure measuring device 60 is used for estimation.

[0107] Specifically, the cylinder pressure measuring device 60 obtains the second torque target value T from the external disturbance observer 42. ω2 *, based on the second torque target value T ω2 ＊ For cylinder internal pressure P eng Perform the calculation. That is, the second torque target value T. ω2 ＊ The external disturbance torque T input to generator 18 d The estimated value is also related to the cylinder pressure P. eng (More specifically, this relates to the reaction force input from engine 17 to generator 18 via crankshaft). Therefore, by referring to a pre-defined correspondence diagram based on the characteristics of engine 17, generator 18, and the drive force transmission system between them, it is possible to determine the second torque target value T. ω2 ＊ For cylinder internal pressure P eng Make an assumption.

[0108] Furthermore, the cylinder pressure P estimated in the cylinder pressure measuring device 60 eng The control maintenance flag reference unit 44 is processed in the same way as in the first embodiment.

[0109] As explained above, in the generator control method of this embodiment, based on the second torque target value T... ω2 ＊ And the cylinder pressure P eng To make an estimate.

[0110] Therefore, even if the cylinder pressure P of engine 17 cannot be directly measured eng In this case, the second torque target value T, which is the output of the external disturbance observer 42, can also be used. ω2 ＊ For cylinder internal pressure P eng Make an estimate and perform control maintenance flag reference unit 44 and subsequent control.

[0111] [Third Implementation]

[0112] The third embodiment will now be described. Furthermore, elements identical to those in the first or second embodiment will be labeled with the same reference numerals and their descriptions will be omitted.

[0113] Figure 5 This is a block diagram showing the main structure of the generator system S according to this embodiment. As shown in the figure, the generator system S of this embodiment, like that of the second embodiment, also has a cylinder pressure P for the engine 17. eng The cylinder pressure measuring device 60 is used for estimation.

[0114] On the other hand, the cylinder pressure measuring device 60 of this embodiment measures the torsional torque T to and the angle of twist θ to As input, the cylinder pressure P eng Estimation is made. Torsional torque T to This is the torque equivalent to the torsional load between the output shaft (rotating component) of generator 18 and the crankshaft of engine 17. Additionally, the torsion angle θ... to This is equivalent to the torsional displacement between the output shaft and crankshaft of generator 18.

[0115] Furthermore, the cylinder pressure measuring device 60 can use only the torsional torque T to and the angle of twist θ to Either one is used as input to control the cylinder pressure P eng The structure is estimated.

[0116] According to the structure of this embodiment, the cylinder pressure P used in the execution of the crankshaft position control described above is realized. eng One method for making a specific inference.

[0117] [Fourth Implementation]

[0118] The fourth embodiment will now be described. Furthermore, elements identical to those in any of the first to third embodiments will be labeled with the same reference numerals and their descriptions will be omitted.

[0119] Figure 6 This is a block diagram showing the main structure of the generator system S according to this embodiment. As shown in the figure, the generator system S of this embodiment, like that of the second and third embodiments, also has a cylinder pressure P for the engine 17. eng The cylinder pressure measuring device 60 is used for estimation.

[0120] On the other hand, the cylinder pressure measuring device 60 in this embodiment measures the crankshaft angle θ of the engine 17. e and crankshaft angular velocity ω e As input, the cylinder pressure P eng An estimation was made. This resulted in a method for controlling the cylinder pressure P. eng One method for making a specific inference.

[0121] Furthermore, the cylinder pressure measuring device 60 can use only the crankshaft angle θ e and crankshaft angular velocity ω e Either one is used as input to control the cylinder pressure P eng The structure is estimated.

[0122] According to the structure of this embodiment, the cylinder pressure P used in the execution of the crankshaft position control described above is realized. eng One method for making a specific inference.

[0123] [Modifications of the fourth embodiment]

[0124] In this modified example, if the crankshaft angular velocity ω obtained from the cylinder pressure measuring device 60 e Less than or equal to the specified value ω eth If the state persists for a time greater than or equal to the specified time Δt, the control switching determination unit 29 sets the control maintenance flag Cf to ON (determining that the cylinder pressure P is positive). eng Less than threshold P ength If this is not the case, the control switching determination unit 29 sets the control maintenance flag Cf to OFF (determining that the cylinder pressure P is OFF). eng Greater than or equal to threshold P ength ).

[0125] In addition, the specified value ω eth As the cylinder pressure P eng Reaching threshold P ength crankshaft angular velocity ωe The value is specified through experiments, etc. Furthermore, regardless of the actual cylinder pressure P... eng Is it greater than or equal to the threshold P? ength The specified time Δt is defined as being used to temporarily determine the crankshaft angular velocity ω due to any arbitrary reason. e Less than or equal to the specified value ω eth The appropriate value to exclude the situation.

[0126] As explained above, in the generator control method of this modified example, based on the crankshaft angular velocity ω... e With the specified value ω eth The cylinder pressure P is determined by comparing the values ​​between them. eng Is it greater than or equal to the threshold P? ength Specifically, at crankshaft angular velocity ω e Greater than or equal to the specified value ω eth If the pressure in the cylinder is less than the specified time Δt, it is determined that the internal pressure P is... eng Greater than or equal to threshold P ength .

[0127] Therefore, although the actual cylinder pressure P of engine 17 eng It is in a relatively high state, and is tentatively judged to be the crankshaft angular velocity ω. e Less than or equal to the specified value ω eth And the cylinder pressure P eng The lower value allows for more reliable prevention of crankshaft position control termination.

[0128] [Control Results]

[0129] The control results of each implementation method (example) will be compared with the control results of the comparative example below.

[0130] (Comparative Example)

[0131] Figure 7 This is a timing diagram illustrating the control results of the proportional control. The proportional control differs from the control logic of the above-described implementation in that, regardless of the cylinder pressure P of engine 17... eng The engine stop command detection is used as the baseline (time t1) to initiate crankshaft position control, regardless of the crankshaft position (crankshaft angle θ). e Reach the target stopping position (target crankshaft angle θ) e ＊ The crankshaft position control ends at the timing (time t2).

[0132] As shown in the figure, in the proportional control, before time t1, generator 18 is configured to make the speed follow the speed command value ω. g ＊The action is performed in this manner. On the other hand, after time t1, crankshaft position control begins, and generator 18 adjusts the crankshaft angle θ. e Approaching target crankshaft angle θ e ＊ The method (so that the angle detection value θ of generator 18) g Follow angle command value θ g ＊ The action is performed in the manner described above. Furthermore, if the crankshaft angle θ is at time t2... e To achieve the target crankshaft angle θ e ＊ Then, crankshaft position control ends. Here, at the moment t2 when crankshaft position control ends, the cylinder pressure P... eng It is in a state of being high to greater than or equal to a constant value. Therefore, due to the residual cylinder pressure P even after the crankshaft position control ends. eng The influence of the crankshaft angle θ e Offset from target crankshaft angle θ e ＊ This results in positioning errors.

[0133] (Example)

[0134] Figure 8 This is a timing diagram illustrating the control results of an embodiment. As shown in the diagram, in the control of this embodiment, even if the crankshaft angle θ... e To achieve the target crankshaft angle θ e ＊ If the cylinder pressure P eng If the value is greater than or equal to a constant value, crankshaft position control continues. Furthermore, the cylinder pressure P... eng Crankshaft position control ends at time t2, which is less than or equal to a constant value. Therefore, after crankshaft position control ends, the crankshaft angle θ is more reliably maintained. e Maintain the target crankshaft angle θ e *

[0135] The embodiments of the present invention have been described above, but the structures described in the above embodiments and various modifications only illustrate a part of the application cases of the present invention, and their purpose is not to limit the technical scope of the present invention.

[0136] For example, in the above embodiments, a generator control method performed using a generator system S mounted on an electric vehicle 100 has been described. However, the generator control method of the present invention can also be performed in the same way by using the generator system S in vehicles other than the electric vehicle 100 or other devices.

Claims

1. A generator control method for controlling a generator driven by an engine via the engine crankshaft, wherein, Determine whether the engine has stopped. If the engine is determined to have stopped, the generator is operated to adjust the crankshaft position to a predetermined target stopping position. Determine whether the cylinder pressure of the engine is greater than or equal to a specified threshold. If the cylinder pressure is greater than or equal to the threshold, crankshaft position control is performed to continuously operate the generator and maintain the crankshaft position at the target stop position. In the crankshaft position control... Obtain an external disturbance torque equivalent to the external disturbance input to the generator. The first torque target value of the generator is calculated in such a way that the detected rotation angle value of the generator follows the rotation angle command value corresponding to the target stop position of the crankshaft position. By processing the generator's speed detection value using an external disturbance observation filter, a second torque target value, which is the estimated external disturbance torque corresponding to the control system model, is calculated. The basic torque command value of the generator is calculated by subtracting the second torque target value from the first torque target value. When the cylinder pressure is greater than or equal to the threshold, the generator's output torque is set to the sum of the basic torque command value and the external disturbance torque. If the cylinder pressure is less than the threshold value, the generator output torque is set to be the same as the external disturbance torque. Even after the crankshaft position reaches the target stop position after the engine stops, if the cylinder pressure is greater than or equal to the threshold, it is maintained at the sum of the basic torque command value and the external disturbance torque, thereby maintaining the crankshaft position at the target stop position.

2. The generator control method according to claim 1, wherein, Based on the second torque target value, the cylinder pressure is estimated.

3. The generator control method according to claim 1, wherein, The cylinder pressure is estimated based on the torsional torque and / or torsional angle of the power transmission system between the crankshaft and the generator.

4. The generator control method according to claim 1, wherein, The cylinder pressure is estimated based on the crankshaft angle and / or crankshaft angular velocity.

5. The generator control method according to claim 4, wherein, The determination of whether the cylinder pressure is greater than or equal to the threshold value is based on a comparison between the crankshaft angular velocity and a specified value. If the crankshaft angular velocity is greater than or equal to the specified value for less than a specified time, it is determined that the cylinder pressure is greater than or equal to the threshold.

6. A generator control device for controlling a generator driven by an engine via the engine crankshaft, wherein, The generator control device has: The stop determination unit determines whether the engine has stopped; If the control unit determines that the engine has stopped, the control unit operates the generator to adjust the crankshaft position to a predetermined target stopping position; The cylinder pressure determination unit determines whether the cylinder pressure of the engine is greater than or equal to a predetermined threshold. as well as The control and maintenance unit continuously operates the generator to maintain the crankshaft position at the target stop position when the cylinder pressure is greater than or equal to the threshold. The control and maintenance unit. Obtain an external disturbance torque equivalent to the external disturbance input to the generator. The first torque target value of the generator is calculated in such a way that the detected rotation angle value of the generator follows the rotation angle command value corresponding to the target stop position of the crankshaft position. By processing the generator's speed detection value using an external disturbance observation filter, a second torque target value, which is the estimated external disturbance torque corresponding to the control system model, is calculated. The basic torque command value of the generator is calculated by subtracting the second torque target value from the first torque target value. When the cylinder pressure is greater than or equal to the threshold, the generator's output torque is set to the sum of the basic torque command value and the external disturbance torque. If the cylinder pressure is less than the threshold value, the generator output torque is set to be the same as the external disturbance torque. Even after the crankshaft position reaches the target stop position after the engine stops, if the cylinder pressure is greater than or equal to the threshold, it is maintained at the sum of the basic torque command value and the external disturbance torque, thereby maintaining the crankshaft position at the target stop position.

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