Vehicle and vehicle control method

Abstract

We provide vehicles and other devices that enable novel assist control. [Solution] The vehicle comprises wheels, a driving source that drives the wheels, a first input device that receives input for an operation to accelerate the vehicle, and a control circuit that controls the driving source based on an operation amount input to the first input device. The control circuit is configured to determine a reference output which is the output of the driving source based on the operation amount, determine whether or not at least two preset assist conditions are satisfied, perform assist control which controls the driving source based on an assist output increased from the reference output if at least two of the assist conditions are satisfied, and perform normal control which controls the driving source based on the reference output if there are fewer than two of the assist conditions that are satisfied.

Description

Technical Field

[0001] The present disclosure relates to a vehicle and a method for controlling the vehicle.

Background Art

[0002] Patent Document 1 discloses torque assist control for correcting a reference output of a drive motor based on an accelerator operation amount by adding an additional value in a hybrid vehicle. The additional value is a value corresponding to a difference obtained by subtracting a threshold value corresponding to a vehicle speed from a change rate of the accelerator operation amount.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the magnitude of the additional value and the timing of adding the additional value to the reference output depend on the change rate of the accelerator operation amount and the vehicle speed.

[0005] One aspect of the present disclosure aims to provide a vehicle and a method for controlling the vehicle that realize a novel assist control.

Means for Solving the Problems

[0006] A vehicle according to one aspect of the present disclosure includes wheels, a driving source that drives the wheels, a first input device that receives input for an operation to accelerate the vehicle, and a control circuit that controls the driving source based on an input variable to the first input device, wherein the control circuit is configured to determine a reference output which is the output of the driving source based on the input variable, determine whether or not at least two preset assist conditions are satisfied, perform assist control which controls the driving source based on an assist output increased from the reference output if at least two of the assist conditions are satisfied, and perform normal control which controls the driving source based on the reference output if there are fewer than two of the assist conditions that are satisfied. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a side view showing an example of the configuration of a vehicle according to an exemplary embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of the power system of the vehicle shown in Figure 1. [Figure 3] Figure 3 shows an example of the relationship between the filter coefficient, the throttle opening before processing, and the throttle opening after processing in the low-pass filter processing according to the embodiment. [Figure 4] Figure 4 shows an example of the relationship between the change threshold and the throttle opening. [Figure 5] Figure 5 shows an example of a control process related to assist control of the ECU according to the embodiment. [Figure 6] Figure 6 is a flowchart showing an example of the operation flow of the ECU according to the present invention. [Figure 7] Figure 7 is a flowchart showing an example of the operation flow of the ECU according to the embodiment. [Modes for carrying out the invention]

[0008] Illustrative embodiments of the present disclosure are described below with reference to the drawings. The embodiments described below are either comprehensive or specific examples. Components in the following embodiments that are not described in the independent claim representing the highest-level concept are described as optional components. The figures in the accompanying drawings are schematic and not necessarily strictly illustrative. In each figure, substantially identical components are denoted by the same reference numerals, and redundant descriptions may be omitted or simplified.

[0009] In the following, a vehicle 1 according to an exemplary embodiment will be described. Vehicle 1 is a mobile vehicle capable of carrying one or more people. Vehicle 1 is equipped with wheels as a means of movement. Examples of vehicle 1 may include two-wheeled vehicles, three-wheeled vehicles, and four-wheeled vehicles. In this embodiment, vehicle 1 is a motorcycle.

[0010] Figure 1 is a side view showing an example of the configuration of a vehicle 1 according to an exemplary embodiment. As shown in Figure 1, the vehicle 1 includes wheels 10, a driving source 20, a drive structure 30, an input device 40, and a control circuit 50. In this embodiment, the vehicle 1 includes front wheels 11 and rear wheels 12 as the wheels 10. Furthermore, the vehicle 1 includes an internal combustion engine 21 and a rotating electric machine 22 as the driving source 20. Furthermore, the vehicle 1 includes a throttle grip 41 as the input device 40. The throttle grip 41 is one of the first input devices. The throttle grip 41 receives input from the driver for operations to accelerate or decelerate the vehicle 1.

[0011] The internal combustion engine 21 converts the thermal energy obtained by burning fuel into mechanical rotational energy. In this embodiment, the internal combustion engine 21 is a reciprocating engine. The internal combustion engine 21 transmits the rotational power of the crankshaft 21c, which is generated by the repeated combustion explosions of a fuel-air mixture in the cylinder of the cylinder block 21b, to the drive structure 30. The rotational power transmitted to the drive structure 30 is transmitted to the rear wheels 12, which are the drive wheels, and the rear wheels 12 are driven by the rotational power to move the vehicle 1.

[0012] The rotating electric machine 22 has a power generation function that converts electrical energy into mechanical rotational energy. Furthermore, the rotating electric machine 22 has a power generation function that converts mechanical rotational energy into electrical energy. The rotating electric machine 22 converts electrical energy into rotational motion of its drive shaft and transmits the rotational power of the drive shaft to the drive structure 30. The rotational power transmitted to the drive structure 30 is then transmitted to the rear wheels 12.

[0013] In this embodiment, vehicle 1 is a hybrid vehicle that runs using either or both of the rotational power output by the internal combustion engine 21 and the rotational power output by the rotating electric machine 22.

[0014] Herein, in this specification, the upward, downward, forward, backward, left, and right directions are directions relative to Vehicle 1 positioned upright on a horizontally extending ground. The upward direction refers to the direction from the ground toward Vehicle 1, and the downward direction refers to the direction from Vehicle 1 toward the ground. The forward direction refers to the direction of movement of Vehicle 1. The backward, left, and right directions indicate the corresponding directions relative to a driver straddling Vehicle 1 in an upright position on the ground.

[0015] Vehicle 1 further comprises a body frame 101, handlebars 102, steering shaft 103, a pair of left and right front forks 104, a swing arm 105, rear suspension 106, seat 107, fuel tank 108, battery 109, and an electronic control unit 110. The electronic control unit 110 is also called an ECU. Hereafter, the "electronic control unit 110" may be referred to as "ECU110".

[0016] The upper part of the front fork 104 is connected to a pair of brackets 104a arranged at intervals in the vertical direction, and the lower part of the front fork 104 rotatably supports the front wheel 11. The brackets 104a are connected to a steering shaft 103 that supports the handlebar 102. The steering shaft 103 is supported by a head pipe 101a, which is part of the vehicle frame 101, so as to be angularly displaceable. The swing arm 105 supports the rear wheel 12 and extends in the front-rear direction, and is pivotally supported by the vehicle frame 101. The rear suspension 106 is connected to the swing arm 105 and the vehicle frame 101.

[0017] At the upper part of the vehicle frame 101, the fuel tank 108 is located behind the handlebar 102, and the seat 107 on which the driver sits is located behind the fuel tank 108.

[0018] In this embodiment, the battery 109 and the ECU 110 are arranged below the seat 107. The battery 109 includes a plurality of secondary battery cells capable of charging and discharging electric power. The battery 109 stores the electric power generated by the power generation function of the rotating electric machine 22 and supplies the stored electric power to electrical components that use electric power in the vehicle 1. The rotating electric machine 22 is one of the electrical components supplied with electric power from the battery 109.

[0019] The ECU 110 controls the vehicle 1. The ECU 110 includes a control circuit 50.

[0020] The internal combustion engine 21 and the rotating electric machine 22 are arranged in a space surrounded by the vehicle frame 101 between the front wheel 11 and the rear wheel 12, and are fixed to the vehicle frame 101 at a plurality of parts.

[0021] FIG. 2 is a schematic diagram showing an example of the power system of the vehicle 1 in FIG. 1. As shown in FIGS. 1 and 2, the internal combustion engine 21 includes a crankshaft 21c in a crankcase 21a and one or more pistons 21d slidably disposed in a cylinder block 21b and connected to the crankshaft 21c so as to be able to transmit driving force. The internal combustion engine 21 reciprocates the piston 21d by repeating combustion explosions of a mixture of fuel and air in the cylinder of the cylinder block 21b. The internal combustion engine 21 converts the reciprocating motion of the piston 21d due to combustion explosion into the rotational motion of the crankshaft 21c and outputs the rotational power of the crankshaft 21c.

[0022] The drive structure 30 includes a clutch 31, a transmission 32, and a power transmission member 33. The transmission 32 includes an input shaft 32a, an output shaft 32b, and a plurality of gears 32c disposed on the input shaft 32a and the output shaft 32b. The transmission 32 can change the reduction ratio between the rotational power input to the input shaft 32a and the rotational power output from the output shaft 32b by changing the combination of the gears 32c that transmit power from the input shaft 32a to the output shaft 32b. For example, a high reduction ratio is a reduction ratio for low-speed driving, and a low reduction ratio is a reduction ratio for high-speed driving. The input shaft 32a is connected to the clutch 31. Further, the clutch 31 is connected to the crankshaft 21c. Thereby, the input shaft 32a is connected to the crankshaft 21c via the clutch 31 so as to be able to transmit power. The output shaft 32b is connected to the power transmission member 33.

[0023] In the present embodiment, the drive structure 30 includes a transmission actuator 32d that controls the reduction ratio selected by the transmission 32. For example, the transmission actuator 32d moves the gear 32c of the input shaft 32a or the output shaft 32b in the axial direction to change the set of gears 32c that are gear-engaged to transmit rotational power between the input shaft 32a and the output shaft 32b. In the present embodiment, the transmission actuator 32d rotates a shift drum included in the transmission 32 to move a shift fork in the axial direction and move the gear 32c by the shift fork. The operation of the transmission actuator 32d is controlled by the ECU 110.

[0024] The power transmission member 33 includes a plurality of members that connect the output shaft 32b and the rear wheel 12. For example, the power transmission member 33 includes a sprocket or pulley connected to the output shaft 32b, a sprocket or pulley connected to the rear wheel 12, and a chain or belt stretched across the two sprockets or two pulleys. This allows the output shaft 32b to be power-transmitted to the rear wheel 12 via the power transmission member 33.

[0025] The clutch 31 has a structure that connects and disconnects the transmission of power between the crankshaft 21c and the input shaft 32a. In this embodiment, the drive structure 30 includes a clutch actuator 31a that controls the drive of the clutch 31 between the connected and disconnected states. When the clutch 31 is connected, the rotational power of the internal combustion engine 21 is transmitted to the rear wheels 12. When the clutch 31 is disconnected, the rotational power of the internal combustion engine 21 is not transmitted to the rear wheels 12. The operation of the clutch actuator 31a is controlled by the ECU 110.

[0026] The rotating electric machine 22 includes a drive shaft 22a that rotates when power is supplied. The rotating electric machine 22 generates power by rotating the drive shaft 22a and supplies the generated power to the battery 109. The drive shaft 22a is connected to the input shaft 32a of the transmission 32 so as to be able to transmit power via a power transmission member 34. Examples of power transmission members 34 may include chains, belts, gears, and pulleys. The connection structure of the power transmission member 34 may be the same as that of the power transmission member 33. The drive shaft 22a of the rotating electric machine 22 is connected to the input shaft 32a regardless of the engaged and disengaged state of the clutch 31. Therefore, the rotating electric machine 22 transmits rotational power to the rear wheel 12 via the transmission 32 when power is supplied. The rotating electric machine 22 generates power when the drive shaft 22a is forcibly rotated by the rear wheel 12 via the transmission 32.

[0027] Vehicle 1 includes a drive circuit 22b for a rotating electric machine 22. The drive circuit 22b controls the supply and receipt of power between the battery 109 and the rotating electric machine 22 according to the control of the ECU 110. The drive circuit 22b controls the rotating electric machine 22 by controlling the power supplied to the rotating electric machine 22 from the battery 109. The drive circuit 22b controls the rotational speed of the rotating electric machine 22 by controlling the voltage of the power supplied to the rotating electric machine 22. The drive circuit 22b controls the output torque of the rotating electric machine 22 by controlling the current of the power supplied to the rotating electric machine 22. The drive circuit 22b may include an inverter or converter that converts power between DC power and AC power.

[0028] Vehicle 1, as described above, is a parallel hybrid vehicle. However, Vehicle 1 may be a hybrid vehicle of other types, such as a split hybrid. Vehicle 1 runs by driving one or both of the internal combustion engine 21 and the rotating electric machine 22, depending on the driving state of Vehicle 1. In this embodiment, Vehicle 1 runs in a driving mode selected from HEV (Hybrid Electric Vehicle) mode, charging mode, and EV (Electric Vehicle) mode. In HEV mode, the clutch 31 is engaged, and Vehicle 1 can run using the power of both the internal combustion engine 21 and the rotating electric machine 22. In EV mode, the clutch 31 is disengaged, and Vehicle 1 can run using only the power of the rotating electric machine 22. In charging mode, the clutch 31 is engaged, and Vehicle 1 runs using only the power of the internal combustion engine 21, while the rotating electric machine 22 generates electricity by being forcibly rotated by the internal combustion engine 21.

[0029] In this embodiment, the vehicle 1 operates in a transmission mode selected from a manual transmission mode and an automatic transmission mode. Therefore, the vehicle 1 includes a manual transmission structure for the driver to directly operate the clutch 31 and the transmission 32, and an automatic transmission structure for operating the clutch 31 and the transmission 32 without driver operation. The automatic transmission structure is realized by a clutch actuator 31a, a transmission actuator 32d, and an ECU 110, etc.

[0030] Vehicle 1 includes a clutch lever 31b and a shift operator 42 as elements for realizing a manual transmission structure. The clutch lever 31b is an operator that receives input from the driver's operation to engage and disengage the clutch 31. The clutch lever 31b is located on the steering wheel 102. In this embodiment, the clutch lever 31b is mechanically connected to the clutch 31. The operation of the clutch lever 31b given by the driver's operation is mechanically transmitted to the clutch 31, which engages and disengages the clutch 31. The clutch lever 31b may be electrically connected to the ECU 110. A signal indicating the operation of the clutch lever 31b is output to the ECU 110, and the ECU 110 may control the clutch actuator 31a to engage and disengage the clutch 31 according to the signal.

[0031] The shift operator 42 is one of the input devices 40 and also one of the second input devices. The shift operator 42 is an operator that receives input for specifying the reduction ratio to be selected by the transmission 32. The shift operator 42 may be a shift pedal located on the vehicle frame 101, etc., or a shift button or shift lever located on the steering wheel 102, etc. In this embodiment, the shift operator 42 is a shift pedal and is mechanically connected to the transmission 32. The operation of the shift operator 42 given by the driver is mechanically transmitted to the transmission 32, changing the reduction ratio selected by the transmission 32. The shift operator 42 may be electrically connected to the ECU 110. A signal indicating the input given to the shift operator 42 is output to the ECU 110, and the ECU 110 may control the transmission actuator 32d to change the selected reduction ratio according to the signal.

[0032] Vehicle 1 further includes various controls. Specifically, Vehicle 1 includes a drive mode selector 43. The drive mode selector 43 is one of the input devices 40. The drive mode selector 43 receives input for selecting a drive mode from among HEV mode, charging mode, and EV mode. In this embodiment, the drive mode selector 43 is located on the steering wheel 102. The drive mode selector 43 includes controls that accept input from the driver's hand, such as buttons, levers, or touch panels. The drive mode selector 43 outputs a signal to the ECU 110 indicating the selected drive mode.

[0033] Furthermore, the vehicle 1 includes a gear shift mode selector 44. The gear shift mode selector 44 is one of the input devices 40. The gear shift mode selector 44 receives input for selecting a gear shift mode from among manual gear shift mode and automatic gear shift mode. In this embodiment, the gear shift mode selector 44 is located on the steering wheel 102. The gear shift mode selector 44 includes an operator that accepts input from the driver's hand, such as a button, lever, or touch panel. The gear shift mode selector 44 outputs a signal to the ECU 110 indicating the selected gear shift mode.

[0034] Vehicle 1 includes various sensors. Specifically, Vehicle 1 includes a first rotation sensor 121 that detects the rotational speed of the crankshaft 21c of the internal combustion engine 21. The rotational speed correlates with the rotational velocity. The first rotation sensor 121 may be located on a flywheel or crank pulley mounted to rotate integrally with the end of the crankshaft 21c, or on a camshaft to which the rotational power of the crankshaft 21c is transmitted. The first rotation sensor 121 outputs the detection result to the ECU 110. Examples of the first rotation sensor 121 may include an electromagnetic pickup type rotation sensor, a ferromagnetic magnetoresistive (AMR) rotation sensor, a Hall IC type rotation sensor, and a mechanical, optical, magnetic, or electromagnetic induction type encoder. The rotational speed may be expressed as revolutions per minute.

[0035] Vehicle 1 includes a second rotation sensor 122 that detects the rotational speed of the drive shaft 22a of the rotating electric machine 22. The second rotation sensor 122 outputs the detection result to the ECU 110. An example of the second rotation sensor 122 is the same as an example of the first rotation sensor 121.

[0036] Vehicle 1 includes a third rotation sensor 123 that detects the rotational speed of the input shaft 32a of the transmission 32. The third rotation sensor 123 outputs the detection result to the ECU 110. An example of the third rotation sensor 123 is the same as an example of the first rotation sensor 121.

[0037] Vehicle 1 includes a gear position sensor 124 that detects the reduction ratio selected by the transmission 32. In this embodiment, the gear position sensor 124 is configured to detect the reduction ratio by detecting the operation of the shift drum or shift fork of the transmission 32. The gear position sensor 124 outputs the detection result to the ECU 110.

[0038] Vehicle 1 includes a clutch sensor 125 that detects the engagement and disengagement of the clutch 31. For example, the clutch sensor 125 may detect both the engagement and disengagement of the clutch 31. The clutch sensor 125 outputs a detection signal to the ECU 110.

[0039] Vehicle 1 includes a throttle position sensor 126 that detects the operating position of the throttle grip 41. The throttle position sensor 126 outputs a detection signal to the ECU 110. An example of the throttle position sensor 126 is the same as that of the first rotation sensor 121.

[0040] The throttle grip 41 is located on the handle 102. The throttle grip 41 has a cylindrical shape and is rotatable around its cylindrical axis. The operating position of the throttle grip 41 is its rotational position. The throttle grip 41 is an operator that receives input from the driver.

[0041] Vehicle 1 includes a wheel speed sensor 127 on the rear wheel 12. The wheel speed sensor 127 detects the rotation speed of the rear wheel 12 and outputs a detection signal to the ECU 110. An example of the wheel speed sensor 127 is the same as the example of the first rotation sensor 121. The wheel speed sensor 127 may be located on the front wheel 11 and detect the rotation speed of the front wheel 11. The wheel speed sensor 127 or the ECU 110 may detect the speed of vehicle 1 from the rotation speed. Vehicle 1 may include a position detection sensor using GNSS (Global Navigation Satellite System) to detect the position of vehicle 1 on Earth. In this case, the ECU 110 may detect the speed of vehicle 1 based on the time change of position information acquired by the position detection sensor.

[0042] Vehicle 1 includes a temperature sensor 128 that detects the temperature state of the battery 109. In this embodiment, the temperature sensor 128 is positioned between the secondary battery cells of the battery 109 and detects the temperature of the secondary battery cells. The temperature sensor 128 outputs a detection signal to the ECU 110.

[0043] The ECU110 may include a microcomputer comprising one or more processors P, such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), and a memory M. The ECU110 may also include a clock for timing. The memory M may include one or more memories, one or more storage devices, or both. An example of memory may include semiconductor memory. An example of storage may include semiconductor memory, a hard disk drive (HDD), and a solid state drive (SSD). An example of semiconductor memory may include volatile memory such as RAM (Random Access Memory) and non-volatile memory such as ROM (Read-Only Memory). The ECU110 may include processing circuits. The ECU110 may include at least a portion of the memory M in the processing circuits.

[0044] Some or all of the functions of the ECU110 may be realized by the CPU using RAM as working memory to execute a program recorded in ROM. Some or all of the functions of the ECU110 may be realized by dedicated hardware circuits such as electronic circuits or integrated circuits. Some or all of the functions of the ECU110 may be realized by a combination of the above-mentioned software functions and hardware circuits. Communication between devices mounted on the vehicle 1, such as the ECU110, various actuators and various sensors, may be communicated via an in-vehicle network such as CAN (Controller Area Network).

[0045] The ECU 110 controls the operation of the internal combustion engine 21 and the rotating electric machine 22. The ECU 110 controls the operation of the clutch 31, the internal combustion engine 21 and the rotating electric machine 22 according to the drive mode selected in the drive mode selector 43. The ECU 110 autonomously determines the drive mode based on the state of the vehicle 1, such as the operating efficiency of the internal combustion engine 21 and the rotating electric machine 22, and controls the operation of the clutch 31, the internal combustion engine 21 and the rotating electric machine 22 according to the determined drive mode.

[0046] The ECU 110 controls the operation of the internal combustion engine 21 by controlling the operation of one or more internal combustion engine actuators 210 that control the drive of the internal combustion engine 21. The one or more internal combustion engine actuators 210 include at least a throttle actuator 211, a fuel injection actuator 212, and an ignition actuator 213. The throttle actuator 211 drives a throttle valve 211a that regulates the flow rate of air entering the cylinder block 21b. The fuel injection actuator 212 includes a fuel injection valve that injects fuel into the cylinder block 21b. The ignition actuator 213 includes a spark plug that ignites the air-fuel mixture in the cylinder block 21b.

[0047] The ECU 110 adjusts the torque output by the internal combustion engine 21 in response to detection signals from sensors in the vehicle 1, including the detection signal from the throttle position sensor 126 indicating the operation of the throttle grip 41. For example, the ECU 110 controls the operation of the throttle actuator 211, fuel injection actuator 212, and ignition actuator 213 so that the internal combustion engine 21 satisfies the torque corresponding to the rotational speed of the input shaft 32a of the transmission 32, the vehicle speed, and the throttle opening.

[0048] The ECU 110 adjusts the torque output by the rotating electric machine 22 in response to detection signals from sensors in the vehicle 1, including the detection signal from the throttle position sensor 126 indicating the operation of the throttle grip 41. For example, the ECU 110 controls the drive circuit 22b of the rotating electric machine 22 so that the rotating electric machine 22 satisfies the torque requirements corresponding to the rotational speed of the input shaft 32a of the transmission 32, the vehicle speed, and the throttle opening.

[0049] The ECU 110 controls the operation of the transmission 32 in automatic transmission mode. For example, when the rotational speed of the internal combustion engine 21 reaches a preset rotational speed, the ECU 110 operates the transmission actuator 32d to operate the transmission 32 so that the reduction ratio selected by the transmission 32 becomes smaller. For example, when the throttle position sensor 126 detects that the throttle grip 41 is fully closed, the ECU 110 operates the transmission actuator 32d to operate the transmission 32 so that the reduction ratio of the transmission 32 becomes larger. The fully closed state of the throttle grip 41 is the state in which the throttle grip 41 is not being operated.

[0050] The details of the ECU110's control of the drive source 20 are described below. The ECU110 determines the torque required for the drive source 20 using the rotational speed of the input shaft 32a of the transmission 32, the command value of the load of the drive source 20, and the reduction ratio selected by the transmission 32. For each reduction ratio selectable by the transmission 32, the ECU110 stores a preset relationship between the rotational speed of the input shaft 32a, the command value of the load of the drive source 20, and the torque required for the drive source 20 in the memory M.

[0051] The ECU 110 obtains the rotational speed of the input shaft 32a from the third rotation sensor 123 and the reduction ratio selected by the transmission 32 from the gear position sensor 124. The command value of the load is related to the rotational position of the throttle grip 41 detected via the throttle position sensor 126. The ECU 110 can determine the command value of the load based on the rotational position of the throttle grip 41. The torque required by the driving power source 20 corresponds to the torque required by the driver of the vehicle 1. Hereinafter, the torque required by the driving power source 20 may be referred to as the "rider-requested torque". The rider-requested torque is one of the reference outputs.

[0052] The ECU 110 may store pre-set rider request torque maps in the memory unit M. The rider request torque map is a table of graphs that show how the torque required by the driving drive source 20 is determined by the rotational speed of the input shaft 32a and the load on the driving drive source 20. The rider request torque map is set for each reduction ratio selectable by the transmission 32. The ECU 110 can determine the rider request torque required by the driving drive source 20 using the rider request torque map corresponding to the reduction ratio selected by the transmission 32, the detection result of the third rotation sensor 123, and the detection result of the throttle position sensor 126.

[0053] In HEV mode, the Rider-required torque is the sum of the engine-required torque, which is the torque required by the internal combustion engine 21, and the motor-required torque, which is the torque required by the rotating electric machine 22. The required torque ratio, which is the ratio of the engine-required torque to the motor-required torque within the Rider-required torque, is preset. The required torque ratio may be constant, but it may vary depending on one or more of the rotational speed of the input shaft 32a, the reduction ratio selected in the transmission 32, and the speed of the vehicle 1.

[0054] The internal combustion engine 21 can generate relatively high torque in the medium to high rotational speed range within the rotational speed range below the allowable rotational speed set for the internal combustion engine 21, and generates lower torque in the low rotational speed range than in the medium to high rotational speed range, and generates lower torque as the rotational speed decreases. The rotating electric machine 22 can generate relatively high torque in the low rotational speed range within the rotational speed range below the allowable rotational speed set for the rotating electric machine 22, and generates lower torque in the medium to high rotational speed range than in the low rotational speed range, and generates lower torque as the rotational speed increases.

[0055] Therefore, the required torque ratio may vary such that the ratio of the engine's required torque increases as the rotational speed of the input shaft 32a increases. The required torque ratio may also vary such that the ratio of the engine's required torque increases as the reduction ratio selected by the transmission 32 decreases. The required torque ratio may also vary such that the ratio of the engine's required torque increases as the vehicle speed increases.

[0056] In EV mode, the lidar-required torque is the motor-required torque required by the rotating electric machine 22. In charging mode, the lidar-required torque is the engine-required torque required by the internal combustion engine 21.

[0057] In any drive mode, the ECU 110 determines the target fuel injection amount to supply to the internal combustion engine 21 based on the rotational speed of the internal combustion engine 21 in order to achieve the engine's required torque. The ECU 110 stores in the memory M a preset relationship between the rotational speed of the internal combustion engine 21, the required load of the internal combustion engine 21, and the target fuel injection amount for each reduction ratio selectable by the transmission 32.

[0058] The ECU 110 determines a target current value to apply to the rotating electric machine 22 based on the rotational speed of the rotating electric machine 22 in order to achieve the motor's required torque. The ECU 110 stores in the memory M a preset relationship between the rotational speed of the rotating electric machine 22, the required load of the rotating electric machine 22, and the target current value for each reduction ratio selectable by the transmission 32.

[0059] The ECU 110 may store a pre-set fuel map for the internal combustion engine 21 and a pre-set current map for the rotating electric machine 22 in the memory M.

[0060] The fuel map is a table of graphs in which the target fuel injection amount is determined by the rotational speed of the internal combustion engine 21 and the required load of the internal combustion engine 21. The fuel map is set for each reduction ratio selectable by the transmission 32. The ratio of the required load of the internal combustion engine 21 to the command value of the load of the driving source 20 corresponds to the ratio of the engine required torque to the rider required torque. The ECU 110 can determine the target fuel injection amount using the fuel map corresponding to the reduction ratio selected by the transmission 32, the detection result of the first rotation sensor 121, and the required load of the internal combustion engine 21 based on the detection result of the throttle position sensor 126.

[0061] The current map is a table of graphs in which the target current value is determined by the rotational speed of the rotating electric machine 22 and the required load of the rotating electric machine 22. The current map is set for each reduction ratio selectable by the transmission 32. The ratio of the required load of the rotating electric machine 22 to the commanded load value of the driving source 20 corresponds to the ratio of the motor required torque to the rider required torque. The ECU 110 can determine the target current value using the current map corresponding to the reduction ratio selected by the transmission 32, the detection result of the second rotation sensor 122, and the required load of the rotating electric machine 22 based on the detection result of the throttle position sensor 126.

[0062] The ECU 110 is configured to perform normal control, which controls the driving power source 20 to drive the vehicle 1 in response to the rider's requested torque, and assist control, which controls the driving power source 20 to assist the acceleration of the vehicle 1 more than in normal control. The ECU 110 determines whether a plurality of preset assist conditions are satisfied, and based on the determination result, decides to perform normal control or assist control. In this embodiment, the ECU 110 performs assist control when at least two assist conditions are satisfied, and performs normal control when fewer than two assist conditions are satisfied. In assist control, the ECU 110 controls the driving power source 20 based on the acceleration torque increased from the rider's requested torque. The acceleration torque is one of the assist outputs.

[0063] For example, when vehicle 1 is driving and moves from a flat road to an uphill road, the insufficient torque generated by the driving source 20 may prevent vehicle 1 from accelerating as much as the driver expects, even when the driver operates the throttle grip 41. In such cases, the ECU 110 can compensate for the torque deficiency by performing assist control. As a result, the driver may experience a driving sensation as if a kickdown with a larger reduction ratio has occurred in the transmission 32, even though the reduction ratio selected in the transmission 32 has not been changed.

[0064] In this embodiment, the ECU 110 determines whether or not to start assist control and whether or not to terminate assist control while it is running by determining whether or not to satisfy the assist conditions. Furthermore, the multiple assist conditions used to determine whether to start assist control are different from the multiple assist conditions used to determine whether to terminate assist control.

[0065] The multiple assist conditions used by the ECU110 include a first assist condition relating to the operation of accelerating vehicle 1, a second assist condition relating to the state of vehicle 1, and a third assist condition relating to the state of vehicle 1.

[0066] The first assist condition is that the change in the amount of operation of the throttle grip 41 is greater than or equal to the change threshold Tha. The first assist condition is satisfied when the change in the amount of operation of the throttle grip 41 is greater than or equal to the change threshold Tha, and is not satisfied when the change in the amount of operation of the throttle grip 41 is less than the change threshold Tha.

[0067] The amount of operation of the throttle grip 41 corresponds to the rotational position of the throttle grip 41 detected by the throttle position sensor 126. The amount of operation corresponds to the range from the rotational position of the throttle grip 41 in the fully closed state to the current rotational position of the throttle grip 41. In this embodiment, the amount of operation of the throttle grip 41 is expressed as a percentage of the throttle opening. The throttle opening is the ratio of the amount of operation of the throttle grip 41 to the range from the rotational position of the throttle grip 41 in the fully closed state to the rotational position of the throttle grip 41 in the fully open state. The throttle opening corresponding to the fully closed state of the throttle grip 41 is 0%. The throttle opening corresponding to the fully open state of the throttle grip 41 is 100%. The throttle opening corresponding to the amount of operation of the throttle grip 41 is expressed as a percentage corresponding to the ratio of the amount of operation between 0% and 100%.

[0068] The ECU 110 acquires the change in the amount of the throttle grip 41 manipulated during a preset sampling period of T seconds. Therefore, the ECU 110 acquires detection results from the throttle position sensor 126 every T seconds. The ECU 110 acquires the change in throttle opening between the throttle opening x(n) after the nth sampling period Tn and the throttle opening x(n-1) after the (n-1)th sampling period Tn-1 immediately preceding sampling period Tn, as the change in the manipulated amount. n is a natural number greater than or equal to 2. The change in the manipulated amount corresponds to the change in throttle opening x(n) relative to throttle opening x(n-1). For example, the change in the manipulated amount may be the difference obtained by subtracting throttle opening x(n-1) from throttle opening x(n).

[0069] In this embodiment, the ECU 110 applies a low-pass filter to the throttle opening and uses the processed throttle opening to determine the amount of change in the throttle grip 41's operation. For example, the ECU 110 applies a low-pass filter to the pre-processing throttle opening, which is the throttle opening x(n) after the nth sampling period Tn has elapsed, to obtain the processed throttle opening y(n). The sampling period Tn is the sampling period most recent in the process of determining the amount of change.

[0070] The ECU110 uses the post-processing throttle opening y(n-1) obtained when the sampling period Tn-1 immediately preceding the sampling period Tn has elapsed, to acquire the post-processing throttle opening y(n). Specifically, the ECU110 acquires the post-processing throttle opening y(n) using the following equation 1, where k is the filter coefficient. y(n)=y(n-1)+{x(n)-y(n-1)}×k (Formula 1)

[0071] The ECU 110 obtains the difference {x(n)-y(n)}, which is obtained by subtracting the post-processing throttle opening y(n) from the pre-processing throttle opening x(n), as the change in the amount of the throttle grip 41 is manipulated. Note that the post-processing throttle opening y(n) is the throttle opening after passing through the low-pass filter, and therefore contains information about the throttle opening signal from before the sampling period Tn. For this reason, the difference {x(n)-y(n)} can be treated as the change in the throttle opening after the sampling period Tn-1 has elapsed, relative to the throttle opening after the sampling period Tn-1 has elapsed.

[0072] In this embodiment, the filter coefficient is a variable and is set to a value within the range of 0 to 1. The larger the filter coefficient, the more susceptible the processed throttle opening y(n) is to short-period fluctuations in the throttle opening. The smaller the filter coefficient, the less susceptible the processed throttle opening y(n) is to short-period fluctuations in the throttle opening. For example, as shown in Figure 3, during the period from time t2 to time t3, when the throttle opening fluctuation period is short, the processed throttle opening ya with filter coefficient ka is more susceptible to fluctuations in the pre-processing throttle opening x than the processed throttle opening yb with filter coefficient kb, and is less affected by the low-pass filter processing. Filter coefficient ka is larger than filter coefficient kb. On the other hand, during the period from time t1 to time t2, when the throttle opening fluctuation period is long, the processed throttle opening yb is excessively affected by the low-pass filter processing. Figure 3 is a diagram showing an example of the relationship between the filter coefficient, the pre-processing throttle opening, and the post-processing throttle opening in the low-pass filter processing according to this embodiment.

[0073] Furthermore, the larger the filter coefficient, the smaller the absolute value of the difference {x(n)-y(n)}. The filter coefficient may be a variable that varies depending on the state of vehicle 1. For example, the state of vehicle 1 may include one or more combinations of the following: the variation period of the throttle opening, the reduction ratio selected in the transmission 32, the speed of vehicle 1, the attitude of vehicle 1, and the rotational speed of the input shaft 32a. An example of the attitude of vehicle 1 is the bank angle, which is the amount of tilt of vehicle 1 in the lateral direction.

[0074] In this embodiment, the throttle opening x(n) is the throttle opening corresponding to the rotational position of the throttle grip 41 detected by the throttle position sensor 126 at the time of the elapsed sampling period Tn. The time of the elapsed sampling period Tn is one of the second timings, and the time of the elapsed sampling period Tn-1 is one of the first timings.

[0075] The throttle opening x(n) may be a statistical value of the throttle opening obtained by applying statistical processing to the detection results of the throttle position sensor 126 between the elapsed timing of sampling period Tn and the elapsed timing of sampling period Tn-1. Examples of statistical values ​​may include the mean, median, minimum, maximum, and mode. The mean may include various mean values.

[0076] The change threshold Tha varies according to the amount of operation of the throttle grip 41. Specifically, the change threshold Tha decreases as the throttle opening is larger. In this embodiment, when the ECU 110 compares the change in throttle opening after a sampling period Tn has elapsed with the change threshold Tha, it uses the change threshold Tha corresponding to the throttle opening x(n-1) after the sampling period Tn-1 immediately preceding the sampling period Tn has elapsed.

[0077] Figure 4 shows an example of the relationship between the change threshold Tha and the throttle opening. As shown in Figure 4, in this embodiment, the change threshold Tha decreases linearly as the throttle opening increases. Note that the relationship between the change threshold Tha and the throttle opening is not limited to a linear relationship; any functional or non-functional relationship is acceptable as long as the change threshold Tha decreases as the throttle opening increases.

[0078] The first assist condition is difficult to satisfy when the throttle opening is small and will not be satisfied unless the driver significantly increases the throttle opening. This prevents the assist control from intervening too sensitively when the throttle opening is small and the output of the driving source 20 is small. The first assist condition is easily satisfied when the throttle opening is large and can be satisfied by the driver slightly increasing the throttle opening. This allows the assist control to intervene according to the driver's request when the throttle opening is large and the output of the driving source 20 is large.

[0079] In this embodiment, the second assist condition includes one or more assist prohibition conditions. Therefore, if all assist prohibition conditions are not satisfied, it means that the second assist condition is satisfied, and if at least one assist prohibition condition is satisfied, it means that the second assist condition is not satisfied. In this embodiment, the second assist condition includes the first to third assist prohibition conditions.

[0080] The first assist prohibition condition is that the reduction ratio selected in the transmission 32 is greater than the reduction ratio threshold Thb. The first assist prohibition condition is satisfied when the reduction ratio selected in the transmission 32 is greater than the reduction ratio threshold Thb, and the first assist prohibition condition is not satisfied when the reduction ratio selected in the transmission 32 is less than or equal to the reduction ratio threshold Thb.

[0081] For example, if six reduction ratios, from the first to the sixth reduction ratio, are selectable in the transmission 32, the first assist prohibition condition may be that one of the reduction ratios from the first to the (k-1)th reduction ratio, which is greater than the kth reduction ratio, is selected in the transmission 32. The six reduction ratios decrease sequentially from the first to the sixth reduction ratio. The kth reduction ratio is the reduction ratio closest to the reduction ratio threshold Thb among the reduction ratios less than or equal to the reduction ratio threshold Thb. k is a natural number greater than or equal to 2.

[0082] When the first assist prohibition condition is satisfied, the torque generated by the internal combustion engine 21 and the rotating electric motor 22 is increased relatively significantly and transmitted to the rear wheels 12. Therefore, the torque generated by the internal combustion engine 21 and the rotating electric motor 22 can satisfy the driver's request for acceleration of the vehicle 1 via the operation of the throttle grip 41. When the first assist prohibition condition is not satisfied, the torque generated by the internal combustion engine 21 and the rotating electric motor 22 may be insufficient to meet the above request.

[0083] The second assist prohibition condition is that the rotational speed of the input shaft 32a of the transmission 32 is equal to or greater than the rotational speed threshold Thc. The second assist prohibition condition is satisfied when the rotational speed of the input shaft 32a is equal to or greater than the rotational speed threshold Thc, and is not satisfied when the rotational speed of the input shaft 32a is less than the rotational speed threshold Thc. The rotational speed threshold Thc is one of the first rotational speeds.

[0084] The rotational speed threshold Thc corresponds to the rotational speed at which the drive source 20 can generate effective torque. The torque generated by the internal combustion engine 21 is small in the low rotational speed range, while the torque generated by the rotating electric machine 22 is large in the low rotational speed range. Therefore, in this embodiment, the rotational speed threshold Thc is set to the rotational speed at which the internal combustion engine 21 can generate effective torque. Since the vehicle 1 is a motorcycle, the internal combustion engine 21 is a high-speed type. For this reason, an example of a rotational speed threshold Thc is 3000 rpm. rpm is the number of revolutions per minute.

[0085] When the second assist prohibition condition is satisfied, the internal combustion engine 21 and the rotating electric machine 22 generate relatively large torque. Therefore, the torque generated by the internal combustion engine 21 and the rotating electric machine 22 can satisfy the driver's request for acceleration of the vehicle 1 via the operation of the throttle grip 41. When the second assist prohibition condition is not satisfied, the torque generated by the internal combustion engine 21 and the rotating electric machine 22 may be insufficient to meet the above request.

[0086] The third assist prohibition condition is that the transmission mode being performed is not automatic transmission mode. The third assist prohibition condition is satisfied when the transmission mode being performed is manual transmission mode, and is not satisfied when the transmission mode being performed is automatic transmission mode. When the transmission mode is not automatic transmission mode, the driver can change the reduction ratio selected in the transmission 32 by operating the shift control 42. For example, if the driver feels that the vehicle 1 is not accelerating well, the driver can improve the acceleration of the vehicle 1 by changing the reduction ratio selected in the transmission 32 to a larger reduction ratio.

[0087] When the third assist prohibition condition is met, torque increase through assist control may not be necessary. When the third assist prohibition condition is not met, torque increase through assist control may be necessary because the transmission mode being performed is automatic transmission mode.

[0088] The second assist condition may further include one or more of the fourth to sixth assist prohibition conditions.

[0089] The fourth assist prohibition condition is that vehicle 1 is driven solely by the rotating electric machine 22. The fourth assist prohibition condition is satisfied when vehicle 1 is driven solely by the rotating electric machine 22, but is not satisfied when vehicle 1 is driven by the internal combustion engine 21 in addition to or instead of the rotating electric machine 22. The torque generated by the rotating electric machine 22 is large, and the amount of torque fluctuation is small even when the rotational speed of the rotating electric machine 22 fluctuates. The torque generated by the internal combustion engine 21 fluctuates greatly in accordance with the fluctuation in the rotational speed of the internal combustion engine 21.

[0090] When the fourth assist prohibition condition is satisfied, the rotating electric machine 22 outputs sufficient torque even if the rotational speed of the input shaft 32a fluctuates, so assist control may not be necessary. When the fourth assist prohibition condition is not satisfied, depending on the rotational speed of the input shaft 32a, the torque generated by the internal combustion engine 21 may be insufficient, and assist control may be necessary.

[0091] The fifth assist prohibition condition is that the state of the clutch 31 detected by the clutch sensor is in the disengaged state. When the clutch 31 is disengaged, the fifth assist prohibition condition is satisfied, and when the clutch 31 is engaged, the fifth assist prohibition condition is not satisfied. When the clutch 31 is disengaged, only the torque generated by the rotating electric machine 22 can be transmitted to the input shaft 32a of the transmission 32. When the clutch 31 is engaged, the torque generated by the internal combustion engine 21 and the rotating electric machine 22 can be transmitted to the input shaft 32a.

[0092] When the fifth assist prohibition condition is satisfied, vehicle 1 is driven solely by the rotating electric motor 22, and therefore, similar to the situation when the fourth assist prohibition condition is satisfied, assist control may be unnecessary. When the fifth assist prohibition condition is not satisfied, vehicle 1 may be driven by the internal combustion engine 21 in addition to or instead of the rotating electric motor 22, and therefore, similar to the situation when the fourth assist prohibition condition is not satisfied, assist control may be necessary.

[0093] The sixth assist prohibition condition is that the temperature of the battery 109, as detected by the temperature sensor 128, is equal to or greater than the temperature threshold Thd. The sixth assist prohibition condition is satisfied when the temperature of the battery 109 is equal to or greater than the temperature threshold Thd, and is not satisfied when the temperature of the battery 109 is less than the temperature threshold Thd. During the execution of assist control, the load on the battery 109 may increase in order to increase the torque of the internal combustion engine 21 and the rotating electric machine 22. If the battery 109, which is above the temperature threshold Thd, is subjected to an excessive load, the performance of the battery 109, such as its durability, may deteriorate. The temperature threshold Thd is one of the first temperatures.

[0094] When the sixth assist prohibition condition is satisfied, it is desirable to prohibit assist control to suppress the increase in load on the battery 109. When the sixth assist prohibition condition is not satisfied, an increase in load on the battery 109 is permissible, and therefore assist control can be performed.

[0095] The third assist condition includes one or more assist termination conditions, and in this embodiment, includes the first to fourth assist termination conditions. The first assist termination condition is that at least one of one or more assist prohibition conditions is satisfied. The first assist termination condition is satisfied when at least one assist prohibition condition is satisfied, and the first assist termination condition is not satisfied when none of the assist prohibition conditions are satisfied. Since it is desirable that assist control is not performed when an assist prohibition condition is satisfied, it is desirable to terminate assist control. The satisfaction of the first assist termination condition also means that the second assist condition is not satisfied.

[0096] The second assist termination condition is that the acceleration assist torque, which is the difference obtained by subtracting the rider-requested torque from the acceleration torque, is zero. When the acceleration assist torque is zero, the second assist termination condition is satisfied, and when the acceleration assist torque is not zero, the second assist termination condition is not satisfied. When the second assist termination condition is satisfied, it is desirable to terminate the assist control because the difference between the acceleration torque and the rider-requested torque is zero. The acceleration assist torque is one of the additional outputs.

[0097] The third assist termination condition is that the throttle opening, based on the detection result of the throttle position sensor 126, is less than or equal to the throttle threshold The. The third assist termination condition is satisfied when the throttle opening is less than or equal to the throttle threshold The, and is not satisfied when the throttle opening exceeds the throttle threshold The.

[0098] In this embodiment, a throttle opening below the throttle threshold The is either fully closed or close to fully closed. For example, the throttle threshold The may be a throttle opening of less than 10%. Furthermore, the throttle threshold The may be a throttle opening corresponding to the idling state of the internal combustion engine 21. When the third assist termination condition is satisfied, it can be assumed that the driver is not requesting acceleration of the vehicle 1 via the operation of the throttle grip 41, and therefore it is desirable to terminate the assist control. The throttle threshold The is one of the first manipulated variables.

[0099] The fourth assist termination condition is the condition detected by the gear position sensor 124 when the reduction ratio selected in the transmission 32 is changed. The fourth assist termination condition is satisfied when the reduction ratio selected in the transmission 32 is changed, and is not satisfied when the reduction ratio selected in the transmission 32 is not changed.

[0100] For example, if the reduction ratio selected in the transmission 32 is changed to a larger reduction ratio, the torque transmitted from the internal combustion engine 21 and the rotating electric machine 22 to the rear wheel 12 increases, and assist control may become unnecessary. If the reduction ratio selected in the transmission 32 is changed to a smaller reduction ratio, the ECU 110 needs to determine the acceleration torque anew and therefore terminates the assist control that is currently running. When the fourth assist termination condition is satisfied, it is desirable for the ECU 110 to terminate the assist control that is currently running in order to determine the acceleration assist torque, which is the difference between the acceleration torque and the rider-requested torque.

[0101] In this embodiment, the ECU 110 terminates normal control and starts assist control when it determines that the first assist condition is satisfied and the second assist condition is also satisfied. The second assist condition being satisfied means that all of the assist prohibition conditions set in the second assist condition are not satisfied. The second assist condition not being satisfied means that at least one of the assist prohibition conditions set in the second assist condition is satisfied.

[0102] In this embodiment, the second assist condition is satisfied if all of the first to third assist prohibition conditions are not satisfied. Therefore, the ECU 110 can perform assist control in HEV mode and charging mode.

[0103] The rider's required torque can be allocated to the engine's required torque and the motor's required torque according to the required torque ratio. The acceleration torque can also be allocated to the engine's acceleration torque and the motor's acceleration torque. The engine's acceleration torque and the motor's acceleration torque may be allocated from the acceleration torque according to the required torque ratio. The engine's acceleration torque is the target torque of the internal combustion engine 21 increased from the engine's required torque, and the motor's acceleration torque is the target torque of the rotating electric machine 22 increased from the motor's required torque.

[0104] When the ECU 110 starts assist control, it increases the torque of the internal combustion engine 21 from the engine request torque to the engine acceleration torque, and increases the torque of the rotating electric machine 22 from the motor request torque to the motor acceleration torque. In this embodiment, the ECU 110 performs tailing processing to gradually increase the torque of the internal combustion engine 21 and the rotating electric machine 22.

[0105] For example, the ECU 110 gradually increases the torque of the internal combustion engine 21 to the engine acceleration torque and gradually increases the torque of the rotating electric machine 22 to the motor acceleration torque over a first tailing time, which is a preset time. The first tailing time is longer than the sampling period T.

[0106] Alternatively, the ECU 110 increases the torque of the internal combustion engine 21 to the engine acceleration torque at a preset first increase speed, and increases the torque of the rotating electric machine 22 to the motor acceleration torque at a preset second increase speed. The first increase speed and the second increase speed are torque increase speeds and can be expressed as the torque value that increases per second. The first increase speed and the second increase speed may be the same or different. The time from the engine required torque to the engine acceleration torque at the first increase speed, and the time from the motor required torque to the motor acceleration torque at the second increase speed, are both longer than the sampling period T. The first increase speed and the second increase speed are one of the first speeds.

[0107] In this embodiment, since the ECU 110 determines the acceleration torque for each sampling period T, the engine acceleration torque and motor acceleration torque may vary for each sampling period T. The ECU 110 increases the torque of the internal combustion engine 21 and the rotating electric machine 22 using the engine acceleration torque and motor acceleration torque determined for each sampling period T as target torques.

[0108] In this embodiment, during the execution of assist control, if the ECU 110 determines that the third assist condition is satisfied, it terminates the assist control and transitions to normal control. The third assist condition being satisfied means that at least one of the assist termination conditions set in the third assist condition is satisfied. The third assist condition not being satisfied means that none of the assist termination conditions set in the third assist condition are satisfied. The third assist condition being satisfied may include satisfying the first assist termination condition, that is, it may include not satisfying the second assist condition.

[0109] When the ECU 110 terminates assist control, it reduces the torque of the internal combustion engine 21 from its current level to the engine's required torque, and reduces the torque of the rotating electric machine 22 from its current level to the motor's required torque. In this embodiment, the ECU 110 performs a tailing process that gradually reduces the torque of both the internal combustion engine 21 and the rotating electric machine 22.

[0110] For example, the ECU 110 gradually reduces the torque of the internal combustion engine 21 to the engine-required torque and gradually reduces the torque of the rotating electric machine 22 to the motor-required torque over a second tailing time, which is a preset time. In this embodiment, the second tailing time is longer than the first tailing time.

[0111] Alternatively, the ECU 110 reduces the torque of the internal combustion engine 21 to the engine-required torque at a preset first descent speed, and reduces the torque of the rotating electric machine 22 to the motor-required torque at a preset second descent speed. The first descent speed and the second descent speed are torque descent speeds and can be expressed as the torque value that decreases per second. The first descent speed and the second descent speed may be the same or different. The absolute value of the first descent speed is smaller than the absolute value of the first ascending speed, and the absolute value of the second descent speed is smaller than the absolute value of the second ascending speed. The time from the current state at the first descent speed to the engine-required torque is longer than the time from the engine-required torque at the first ascending speed to the engine acceleration torque, and the time from the current state at the second descent speed to the motor-required torque is longer than the time from the motor-required torque at the second ascending speed to the motor acceleration torque. The first descent speed and the second descent speed are one of the second speeds.

[0112] In this embodiment, the ECU 110 determines the motor request torque for each sampling period T, so the engine request torque and motor request torque may vary for each sampling period T. The ECU 110 uses the engine request torque and motor request torque determined for each sampling period T as target torques and reduces the torques of the internal combustion engine 21 and the rotating electric machine 22.

[0113] The control process for assist control of the ECU110 according to the embodiment will be described. Figure 5 is a diagram showing an example of the control process for assist control of the ECU110 according to the embodiment. The following description is for the control process in HEV mode. In charging mode, processing related to the rotating electric machine 22 is omitted.

[0114] As shown in Figure 5, in the sensor information acquisition process S1, the ECU 110 acquires detection results from various sensors at each sampling period T. For example, the ECU 110 acquires the detection result when the nth sampling period Tn has elapsed. The ECU 110 acquires at least the rotational speed of the input shaft 32a of the transmission 32 detected by the third rotation sensor 123, the reduction ratio selected in the transmission 32 detected by the gear position sensor 124, and the throttle opening detected by the throttle position sensor 126.

[0115] In the throttle opening change acquisition step S2, the ECU 110 acquires the change in throttle opening between the throttle opening x(n) after the sampling period Tn has elapsed and the throttle opening x(n-1) after the (n-1)th sampling period Tn-1 has elapsed. The ECU 110 may also perform a low-pass filter on the throttle opening and use the processed throttle opening to acquire the change in throttle opening.

[0116] In the acceleration assist torque acquisition process S3, the ECU 110 acquires an acceleration assist torque value to be added to the rider-requested torque value of the driving drive source 20 in order to obtain the acceleration torque value of the driving drive source 20. For example, the ECU 110 calculates the acceleration assist torque value using the rotational speed of the input shaft 32a of the transmission 32, the reduction ratio selected in the transmission 32, and the throttle opening. The rotational speed of the input shaft 32a, the reduction ratio, and the throttle opening are the detection results after the sampling period Tn has elapsed. The ECU 110 stores in the memory M a preset relationship between the rotational speed of the input shaft 32a, the throttle opening, and the acceleration assist torque for each reduction ratio that can be selected in the transmission 32.

[0117] For example, the above relationship regarding acceleration assist torque is set for each of the reduction ratios that can be selected in the transmission 32 and are less than or equal to the reduction ratio threshold Thb. The above relationship regarding acceleration assist torque at each reduction ratio may be set within a range of rotational speed of the input shaft 32a that is greater than or equal to Ra and less than the rotational speed threshold Thc. The range of rotational speed may be the same or different among multiple reduction ratios. The above relationship regarding acceleration assist torque at each reduction ratio may be set within a range of throttle opening that is greater than or equal to Ta% and less than or equal to 100%. The range of throttle opening may be the same or different among multiple reduction ratios.

[0118] In this embodiment, the acceleration assist torque is set to increase as the throttle opening increases in each reduction ratio. Furthermore, the acceleration assist torque is set to increase as the rotational speed of the input shaft 32a increases in each reduction ratio. For example, the acceleration assist torque may be set as a torque that increases the rider-requested torque corresponding to the rotational speed of the input shaft 32a, the reduction ratio selected by the transmission 32, and the throttle opening by a preset rate. The increase rate may vary depending on one or more of the rotational speed of the input shaft 32a, the reduction ratio selected by the transmission 32, and the throttle opening, or it may be a fixed value.

[0119] The ECU 110 may store pre-set acceleration assist torque maps in the memory unit M. The acceleration assist torque map is a table of graphs in which the acceleration assist torque is determined by the rotational speed of the input shaft 32a and the throttle opening. The acceleration assist torque map is set for each reduction ratio selectable by the transmission 32. The ECU 110 can determine the value of the acceleration assist torque using the acceleration assist torque map corresponding to the reduction ratio selected by the transmission 32, the rotational speed of the input shaft 32a, and the throttle opening.

[0120] In the rider-requested torque acquisition process S4, the ECU 110 acquires the value of the rider-requested torque of the driving power source 20. For example, the ECU 110 calculates the value of the rider-requested torque using the rotational speed of the input shaft 32a of the transmission 32, the reduction ratio selected in the transmission 32, and the throttle opening. The rotational speed of the input shaft 32a, the reduction ratio, and the throttle opening are the detection results after the sampling period Tn has elapsed. The ECU 110 stores in the memory M a preset relationship between the rotational speed of the input shaft 32a, the throttle opening, and the rider-requested torque for each reduction ratio selectable by the transmission 32.

[0121] The ECU 110 may store the rider-requested torque map in the memory unit M and use it to calculate the rider-requested torque. The ECU 110 can determine the value of the rider-requested torque using the rider-requested torque map corresponding to the reduction ratio selected in the transmission 32, the rotational speed of the input shaft 32a, and the throttle opening.

[0122] In the acceleration assist determination step S5, the ECU 110 determines whether or not to execute assist control. If normal control is being executed, the ECU 110 determines whether or not to start assist control. If assist control is being executed, the ECU 110 determines whether or not to terminate assist control.

[0123] In determining whether or not to start assist control, the ECU110 determines whether both the first assist condition, which is that the amount of change in throttle opening is greater than or equal to the change threshold Tha, and the second assist condition are satisfied.

[0124] The ECU110 determines that both the first and second assist conditions are met, and decides to start assist control. The second assist condition is met if none of the assist prohibition conditions included in the second assist condition are met.

[0125] If the ECU110 determines that the first or second assist condition is not met, it decides to continue normal control. The second assist condition not being met means that any of the assist prohibition conditions included in the second assist condition are met.

[0126] In determining whether to terminate assist control, the ECU110 determines whether the third assist condition is satisfied. If the ECU110 determines that the third assist condition is satisfied, it decides to terminate assist control. Satisfaction of the third assist condition means that any of the assist termination conditions included in the third assist condition are satisfied.

[0127] If the ECU110 determines that the third assist condition is not met, it decides to continue assist control. The failure to meet the third assist condition means that none of the assist termination conditions included in the third assist condition are met.

[0128] In the torque assist determination step S6, the ECU 110 determines the torque values ​​to be generated by the internal combustion engine 21 and the rotating electric machine 22. For example, in assist control, the ECU 110 calculates the acceleration torque value by adding the acceleration assist torque value to the rider request torque value. The ECU 110 determines the engine acceleration torque value and the motor acceleration torque value by distributing the acceleration torque. The ECU 110 may also determine the engine acceleration torque value and the motor acceleration torque value by adding the engine assist torque value and the motor assist torque value obtained by distributing the acceleration assist torque to the engine request torque value and the motor request torque value obtained by distributing the rider request torque. The engine assist torque and motor assist torque may be distributed from the acceleration assist torque according to the request torque ratio.

[0129] In normal control, the ECU110 determines the engine's requested torque value and the motor's requested torque value by distributing the rider's requested torque.

[0130] In the torque control process S7, the ECU 110 controls the torque generated by the internal combustion engine 21 and the rotating electric machine 22. In assist control, the ECU 110 generates engine acceleration torque and motor acceleration torque for the internal combustion engine 21 and the rotating electric machine 22, respectively. In normal control, the ECU 110 generates engine-required torque and motor-required torque for the internal combustion engine 21 and the rotating electric machine 22, respectively.

[0131] The ECU 110 repeats processes S1 to S7 every sampling period T. The ECU 110 may perform tailing when increasing and decreasing the torque generated in the internal combustion engine 21 and the rotating electric machine 22. The ECU 110 may perform tailing so that the temporal fluctuation of the torque is gentler when decreasing the torque than when increasing it.

[0132] An example of the operation flow of the ECU110 according to the embodiment will be described. Figures 6 and 7 are flowcharts illustrating an example of the operation flow of the ECU110 according to the embodiment. The following description describes the operation of the ECU110 in HEV mode. In charging mode, operations related to the rotating electric machine 22 are omitted.

[0133] As shown in Figures 6 and 7, in step S101, the ECU 110 determines whether or not the timing for the elapsed sampling period T has been reached. If the timing for the elapsed sampling period T has been reached (Yes in step S101), the ECU 110 proceeds to step S102, and if the timing for the elapsed sampling period T has not yet been reached (No in step S101), step S101 is repeated.

[0134] Next, in step S102, the ECU 110 proceeds to step S103 if the control being executed is normal control (Yes in step S102), and proceeds to step S104 if the control being executed is assist control (No in step S102).

[0135] In step S103, the ECU 110 acquires detection results from various sensors, including detection results related to the determination of whether to start assist control.

[0136] Next, in step S105, the ECU 110 acquires the change in throttle opening. The change in throttle opening is obtained based on the throttle opening at the end of sampling period T and the throttle opening at the end of the sampling period immediately preceding sampling period T.

[0137] Next, in step S106, the ECU110 obtains the value of the acceleration assist torque.

[0138] Next, in step S107, the ECU110 obtains the value of the rider's requested torque.

[0139] Next, in step S108, the ECU 110 determines whether the first assist condition and the second assist condition are satisfied. If the first assist condition and the second assist condition are satisfied (Yes in step S108), the ECU 110 proceeds to step S109; if either the first assist condition or the second assist condition is not satisfied (No in step S108), it proceeds to step S110.

[0140] In step S109, the ECU110 decides to start assist control and proceeds to step S111.

[0141] In step S110, the ECU110 decides to continue normal control and proceeds to step S113.

[0142] In step S111, the ECU110 determines the value of the acceleration torque based on the acceleration assist torque and the rider-requested torque. Furthermore, the ECU110 determines the value of the engine acceleration torque and the motor acceleration torque based on the acceleration torque.

[0143] Next, in step S112, the ECU 110 assists and controls the internal combustion engine 21 and the rotating electric machine 22 to generate engine acceleration torque and motor acceleration torque. After step S112, the ECU 110 proceeds to step S101.

[0144] In step S113, the ECU110 determines the engine torque value and the motor torque value based on the rider's requested torque.

[0145] Next, in step S114, the ECU 110 normally controls the internal combustion engine 21 and the rotating electric machine 22 to generate the engine-required torque and the motor-required torque. After step S114, the ECU 110 proceeds to step S101.

[0146] In step S104, the ECU 110 acquires detection results from various sensors, including detection results related to determining the end of assist control.

[0147] Next, in step S115, the ECU110 obtains the value of the acceleration assist torque.

[0148] Next, in step S116, the ECU110 obtains the value of the rider's requested torque.

[0149] Next, in step S117, the ECU 110 determines whether the third assist condition is satisfied. If the third assist condition is satisfied (Yes in step S117), the ECU 110 proceeds to step S118; otherwise, it proceeds to step S119.

[0150] In step S118, the ECU110 decides to terminate the assist control and proceeds to step S120.

[0151] In step S119, the ECU110 decides to continue the assist control and proceeds to step S122.

[0152] In step S120, the ECU110 determines the engine torque and motor torque based on the rider's requested torque.

[0153] Next, in step S121, the ECU 110 normally controls the internal combustion engine 21 and the rotating electric machine 22 to generate the engine-required torque and the motor-required torque. After step S121, the ECU 110 proceeds to step S101.

[0154] In step S122, the ECU110 determines the acceleration torque based on the acceleration assist torque and the rider's requested torque. Furthermore, the ECU110 determines the engine acceleration torque and the motor acceleration torque based on the acceleration torque.

[0155] Next, in step S123, the ECU 110 assists and controls the internal combustion engine 21 and the rotating electric machine 22 to generate engine acceleration torque and motor acceleration torque. After step S123, the ECU 110 proceeds to step S101.

[0156] From steps S101 to S123, the ECU 110 determines whether to perform assist control or normal control at each sampling period T, and controls the internal combustion engine 21 and the rotating electric machine 22 according to the determined control.

[0157] [others] While exemplary embodiments of the present disclosure have been described above, the disclosure is not limited to these embodiments. That is, various modifications and improvements are possible within the scope of the disclosure. For example, embodiments that have been modified in various ways, and forms constructed by combining components from different embodiments, are also included within the scope of the disclosure.

[0158] For example, in the assist control in the embodiment, the ECU 110 distributes the acceleration assist torque to the engine assist torque of the internal combustion engine 21 and the motor assist torque of the rotating electric machine 22 to increase the torque of both the internal combustion engine 21 and the rotating electric machine 22, but the control of the ECU 110 is not limited to this. For example, the ECU 110 may apply the acceleration assist torque to either the internal combustion engine 21 or the rotating electric machine 22 to increase the torque of either the internal combustion engine 21 or the rotating electric machine 22. In the assist control in the charging mode, the ECU 110 may apply the acceleration assist torque to the internal combustion engine 21 only.

[0159] In this embodiment, the ECU 110 is configured not to perform assist control in EV mode, but the configuration of the ECU 110 is not limited to this. The ECU 110 may be configured to perform assist control in EV mode. In assist control in EV mode, the ECU 110 may apply acceleration assist torque only to the rotating electric machine 22.

[0160] In this embodiment, the ECU 110 acquires acceleration assist torque at each sampling period T, regardless of whether assist control or normal control is being performed, but the control of the ECU 110 is not limited to this. For example, the ECU 110 may acquire acceleration assist torque when it decides to continue assist control while assist control is being performed. The ECU 110 may also acquire acceleration assist torque when it decides to start assist control while normal control is being performed.

[0161] In the embodiment, the ECU 110 determines the acceleration assist torque for each reduction ratio selectable by the transmission 32 using a preset relationship between the rotational speed of the input shaft 32a, the throttle opening, and the acceleration assist torque, or using an acceleration assist torque map. However, the control of the ECU 110 is not limited to this. For example, the ECU 110 may determine the acceleration assist torque as a preset proportion of the rider-requested torque. In other words, the acceleration torque may be a torque obtained by increasing the rider-requested torque by a preset proportion. The above proportion may be set for each reduction ratio selectable by the transmission 32. The above proportion may be the same or different among multiple reduction ratios.

[0162] In the embodiment, the second assist condition includes the first to third assist prohibition conditions, or includes the first to third assist prohibition conditions and one or more of the fourth to sixth assist prohibition conditions, but the second assist condition is not limited to these. The second assist condition may include one or more of the first to third assist prohibition conditions, or one or more of the first to sixth assist prohibition conditions.

[0163] In this embodiment, the third assist condition includes the first to fourth assist termination conditions, but the third assist condition is not limited thereto. For example, the third assist condition may include one or more of the first to fourth assist termination conditions.

[0164] In this embodiment, the change threshold Tha is set to fluctuate in response to the throttle opening regardless of the state of the vehicle 1, but the setting of the change threshold Tha is not limited to this. The change threshold Tha may be set so that the relationship between the throttle opening and the change threshold changes depending on the state of the vehicle 1. In other words, the change threshold Tha may be set for each state of the vehicle 1. For example, the state of the vehicle 1 may include one or more combinations of the reduction ratio selected in the transmission 32, the speed of the vehicle 1, the attitude of the vehicle 1, and the rotational speed of the input shaft 32a. An example of the attitude of the vehicle 1 includes the bank angle, which is the amount of tilt of the vehicle 1 in the left-right direction.

[0165] The vehicle 1 according to this embodiment is a hybrid vehicle, but may also be a non-hybrid vehicle without a rotating electric motor 22, or an EV without an internal combustion engine 21. If the vehicle 1 is a non-hybrid vehicle, the ECU 110 may apply acceleration assist torque to the internal combustion engine 21 in assist control. If the vehicle 1 is an EV, the ECU 110 may apply acceleration assist torque to the rotating electric motor 22 in assist control.

[0166] The vehicle 1 according to this embodiment is a saddle-type vehicle, but it may also be a scooter-type vehicle having a footrest in front of the seat. Regardless of the type of vehicle 1, the drive source 20 may be located between the seat 107 and the front wheel 11, or it may be located in another position. For example, the drive source 20 may have a configuration that swings together with the swing arm, as is often seen in scooter-type vehicles.

[0167] The structure of the internal combustion engine 21 mounted on the vehicle 1 according to this embodiment may be any existing structure. For example, the number of cylinders of the internal combustion engine 21 may be either single-cylinder or multi-cylinder. The internal combustion engine 21 may be either a four-stroke engine or a two-stroke engine. The fuel used by the internal combustion engine 21 may also be any fuel, such as fuels containing hydrocarbon compounds such as gasoline, ethanol, propane gas, and methane, fuels derived from animals or plants such as biofuels, or non-carbonized fuels such as hydrogen.

[0168] In the embodiment, vehicle 1 has a structure in which, when shifting gears in manual shift mode, the clutch lever 31b mechanically operates the clutch 31 at the driver's operation, and the shift operator 42 mechanically operates the transmission 32 at the driver's operation. However, the structure of vehicle 1 is not limited to this. For example, vehicle 1 does not have a clutch lever 31b. The shift operator 32e may be electrically connected to the transmission actuator 32d and transmit a signal indicating a specified reduction ratio input by the driver to the clutch actuator 31a and the transmission actuator 32d. The clutch actuator 31a and the transmission actuator 32d may operate the clutch 31 and the transmission 32 respectively according to the received signal to change the reduction ratio selected by the transmission 32 to the specified reduction ratio.

[0169] The vehicle 1 according to this embodiment is equipped with an automatic transmission structure, but the structure of the vehicle 1 is not limited thereto. For example, the vehicle 1 may be equipped only with the manual transmission structure described in the embodiment. Even in such a case, the ECU 110 can start assist control based on the first assist condition and the second assist condition, and end assist control based on the third assist condition. Similarly, the ECU 110 according to this embodiment may be configured to perform assist control in manual transmission mode.

[0170] Examples of each aspect of the technology of this disclosure are as follows. A vehicle according to the first aspect of this disclosure comprises wheels, a driving source that drives the wheels, a first input device that receives input for an operation to accelerate the vehicle, and a control circuit that controls the driving source based on an input variable to the first input device, wherein the control circuit is configured to determine a reference output which is the output of the driving source based on the input variable, determine whether or not at least two preset assist conditions are satisfied, perform assist control which controls the driving source based on an assist output increased from the reference output if at least two of the assist conditions are satisfied, and perform normal control which controls the driving source based on the reference output if there are fewer than two of the assist conditions that are satisfied.

[0171] According to the first embodiment, the control circuit performs either assist control or normal control depending on whether at least two assist conditions are satisfied. By performing assist control, the control circuit can accelerate the vehicle more than with normal control. The timing of the execution of assist control depends on at least two assist conditions. Thus, a novel assist control is obtained.

[0172] In the first embodiment, a vehicle according to a second aspect of the present disclosure may be configured such that the at least two assist conditions include a first assist condition relating to an operation to accelerate the vehicle and a second assist condition relating to the state of the vehicle.

[0173] According to the second embodiment, the timing of the execution of the assist control may depend not only on the operation to accelerate the vehicle, but also on the state of the vehicle. Therefore, a novel assist control that is executed at a suitable timing can be obtained.

[0174] In a third aspect of the present disclosure, the vehicle may be configured in the second aspect to execute the assist control when the first assist condition and the second assist condition are satisfied.

[0175] According to the third embodiment, the control circuit performs assist control when both a first assist condition relating to the operation of accelerating the vehicle and a second assist condition relating to the state of the vehicle are satisfied. Therefore, assist control can be performed at a suitable timing.

[0176] A vehicle according to a fourth aspect of this disclosure may be configured such that, in any of the first to third aspects, at least two of the assist conditions include a condition that the amount of change in the manipulated amount is greater than or equal to a threshold that varies according to the manipulated amount.

[0177] According to the fourth embodiment, the timing of the execution of assist control depends on the change in the manipulated variable and a threshold that varies according to the manipulated variable. In other words, the timing of the execution of assist control depends on the changing manipulated variable. Thus, a novel assist control is obtained. Note that the condition that the change in the manipulated variable is greater than or equal to a threshold that varies according to the manipulated variable may be included in the first assist condition.

[0178] In the fifth aspect of this disclosure, the vehicle may be configured such that the threshold value decreases as the manipulated amount increases, according to the fourth aspect.

[0179] According to the fifth embodiment, the larger the input amount, the smaller the threshold, and the more likely the change in the input amount is to exceed the threshold. In other words, the larger the input amount, the more likely assist control is to be executed. This prevents the vehicle from accelerating in an overly sensitive reaction to an increase in the input amount in the low-speed range of the driving power source, which can degrade the driver's driving feel. In the high-speed range of the driving power source, the vehicle accelerates in a rapid response to the driver's request for acceleration, improving the driver's driving feel.

[0180] In the sixth aspect of this disclosure, the vehicle may be configured such that, in the fourth or fifth aspect, the change in the manipulated amount is the change in the manipulated amount at a second timing later than the first timing, relative to the manipulated amount at a first timing, and the threshold corresponds to the manipulated amount at the first timing.

[0181] According to the sixth embodiment, the control circuit decides whether or not to perform assist control based on a threshold corresponding to the manipulated variable at the first timing and the change in the manipulated variable immediately after the first timing. For example, if the manipulated variable at the first timing is small, the control circuit will not perform assist control unless the change in the manipulated variable immediately after the first timing is large. If the manipulated variable at the first timing is large, the control circuit will perform assist control even if the change in the manipulated variable immediately after the first timing is small. Thus, assist control that appropriately responds to changes in the manipulated variable is realized.

[0182] In any of the first to sixth embodiments of the present disclosure, the vehicle may be configured such that the driving source includes an internal combustion engine and a rotating electric machine, and the control circuit is configured to increase the output of both the internal combustion engine and the rotating electric machine from the reference output of the internal combustion engine and the rotating electric machine, respectively, in the assist control.

[0183] In the seventh embodiment, the relationship between rotational speed and output in an internal combustion engine differs from that in a rotating electric machine. In assist control, the output of both the internal combustion engine and the rotating electric machine is increased, so the desired assist output can be obtained at various rotational speeds.

[0184] A vehicle according to the eighth aspect of this disclosure, in any of the first to seventh aspects, further comprises a transmission that transmits power generated by the driving source to the wheels, and the control circuit may be configured to determine an additional output based on the reduction ratio selected by the transmission, the manipulated amount, and the rotational speed of the driving source, and to determine the assist output by adding the additional output to the reference output.

[0185] According to the eighth aspect, for example, the lower the reduction ratio selected in the transmission, the greater the load on the drive source, and therefore the torque generated by the drive source is less likely to accelerate the vehicle. Furthermore, the torque generated by the drive source depends on the manipulated amount and the rotational speed of the drive source. Therefore, by determining the additional output based on the reduction ratio selected in the transmission, the manipulated amount, and the rotational speed of the drive source, an assist output corresponding to the state of the vehicle can be obtained.

[0186] In the ninth aspect of the present disclosure, the vehicle may, in the eighth aspect, be configured such that the control circuit is released from the assist control when the determined additional output is 0 during the execution of the assist control.

[0187] According to the ninth embodiment, when the additional output is 0, the assist output does not increase from the reference output, and therefore assist control is unnecessary. Thus, the control circuit can cancel the assist control when the additional output is 0 and switch to, for example, normal control.

[0188] A vehicle according to the tenth aspect of this disclosure further comprises, in any of the first to ninth aspects, a transmission that transmits power generated by the driving source to the wheels, wherein the at least two assist conditions may include a condition that the reduction ratio selected by the transmission is less than or equal to a preset reduction ratio.

[0189] In the tenth embodiment, the lower the reduction ratio selected by the transmission, the less the torque generated by the driving source is capable of accelerating the vehicle. The control circuit can effectively assist the acceleration of the vehicle by performing assist control when the reduction ratio selected by the transmission is less than or equal to a preset reduction ratio. The condition that the reduction ratio selected by the transmission is less than or equal to a preset reduction ratio may be included in the second assist condition.

[0190] A vehicle according to an eleventh aspect of the present disclosure, in any of the first to tenth aspects, is configured such that the driving source includes an internal combustion engine and a rotating electric machine, and the vehicle further comprises a drive structure connected to the internal combustion engine and the rotating electric machine so as to transmit power generated by the internal combustion engine and the rotating electric machine, and for transmitting power supplied from the internal combustion engine and the rotating electric machine to the wheels, the drive structure including an input shaft to which power generated by the internal combustion engine and the rotating electric machine is transmitted, and the at least two assist conditions may include a condition that the rotational speed of the input shaft is less than a preset first rotational speed.

[0191] In the eleventh embodiment, if the rotational speed of the input shaft is less than the first rotational speed, the rotational speed of the internal combustion engine is also less than the first rotational speed. Since the torque generated by the internal combustion engine at such rotational speeds may be small, an assist output is required for the driving source. Therefore, the control circuit can perform assist control according to the state of the driving source. Note that the condition that the rotational speed of the input shaft is less than a preset first rotational speed may be included in the second assist condition.

[0192] A vehicle according to a twelfth aspect of the present disclosure, in any of the first to eleventh aspects, is configured such that the driving source includes an internal combustion engine and a rotating electric machine, and the vehicle further comprises a drive structure connected to the internal combustion engine and the rotating electric machine so as to transmit power generated by the internal combustion engine and the rotating electric machine, and which transmits power supplied from the internal combustion engine and the rotating electric machine to the wheels, wherein the at least two assist conditions may include the condition that the drive structure is in a state in which power generated by the internal combustion engine is transmitted to the wheels.

[0193] In the twelfth embodiment, the torque, which is the power generated by the internal combustion engine, fluctuates significantly depending on the rotational speed of the internal combustion engine. The control circuit can assist the torque of the internal combustion engine, which fluctuates significantly depending on the rotational speed, through assist control. The condition that the drive structure is in a state where the power generated by the internal combustion engine is transmitted to the wheels may be included in the second assist condition.

[0194] A vehicle according to a thirteenth aspect of the present disclosure, in any of the first to twelfth aspects, is configured such that the driving source includes an internal combustion engine and a rotating electric machine, and the vehicle further includes a battery electrically connected to the rotating electric machine and a temperature sensor for detecting the temperature of the battery, and the at least two assist conditions may include a condition that the temperature of the battery detected by the temperature sensor is less than or equal to a preset first temperature.

[0195] In the 13th embodiment, when assist control is performed, the battery temperature may rise. Since assist control is performed when the battery temperature is below a first temperature, an excessive rise in battery temperature is prevented. This prevents a decrease in battery durability. The condition that the battery temperature is below a preset first temperature may be included in the second assist condition.

[0196] A vehicle according to a 14th aspect of the present disclosure further comprises, in any of the first to 13th aspects, a transmission that transmits power generated by the driving source to the wheels, a second input that receives input for an operation to specify a reduction ratio selected by the transmission, and a transmission actuator that changes the reduction ratio selected by the transmission, wherein the control circuit selectively performs control in manual shift mode and automatic shift mode, and in automatic shift mode, is configured to control the transmission actuator regardless of an operation input to the second input, and in manual shift mode, the transmission is operated to change the reduction ratio according to the reduction ratio specified in the second input, and the at least two assist conditions may include the condition that the automatic shift mode is being executed.

[0197] In the 14th embodiment, in manual shift mode, the driver can accelerate the vehicle at the desired timing by changing the reduction ratio themselves. In automatic shift mode, the driver cannot accelerate the vehicle by changing the reduction ratio. Therefore, in automatic shift mode, the control circuit performs assist control to accelerate the vehicle according to the driver's request. Note that the condition that automatic shift mode is in operation may be included in the second assist condition.

[0198] In any of the first to fourteenth embodiments of the present disclosure, the vehicle may be configured such that, during the execution of the assist control, the control circuit is deactivated if at least one of the assist conditions that is being satisfied is no longer being satisfied.

[0199] In the 15th embodiment, if at least one of the satisfied assist conditions is not satisfied, assist control may become unnecessary. When such a condition occurs, the control circuit can release the assist control and, for example, switch to normal control.

[0200] In any of the 16th aspect of this disclosure, the vehicle may be configured such that, in any of the 1st to 15th aspects, the control circuit is configured to release the assist control if the manipulated amount falls to or below a preset first manipulated amount while the assist control is being performed.

[0201] In the 16th embodiment, when the manipulated amount of the first input device is less than or equal to the first manipulated amount, the driver does not request acceleration of the vehicle, and assist control may become unnecessary. When such a state occurs, the control circuit can release the assist control and switch to, for example, normal control.

[0202] A vehicle according to a 17th aspect of the present disclosure further comprises, in any of the 1st to 16th aspects, a transmission that transmits power generated by the driving source to the wheels, and the control circuit may be configured to cancel the assist control if the reduction ratio selected in the transmission is changed while the assist control is being performed.

[0203] In the 17th embodiment, when the reduction ratio selected in the transmission is changed, the output that should be increased from the reference output may become unnecessary or change. The control circuit can respond to the variation in the output that should be increased from the reference output by disengaging the assist control that is currently being performed.

[0204] In the 18th aspect of the present disclosure, in any of the 1st to 17th aspects, the control circuit is configured such that when the assist control is started, it increases the output of the driving source from the reference output to the assist output at a first speed, and when the assist control that is in progress is released, it decreases the output of the driving source from the assist output to the reference output at a second speed, and the magnitude of the first speed may be greater than the magnitude of the second speed.

[0205] According to the 18th embodiment, abrupt power fluctuations are prevented when assist control is started and stopped. When assist control is started, the output of the driving source increases at a first speed to respond to the driver's request for acceleration. When assist control is stopped, the output of the driving source decreases gently at a second speed to avoid giving the driver a feeling of deceleration. As a result, the driver's driving feeling is improved.

[0206] A vehicle control method according to a 19th aspect of the present disclosure includes: acquiring information on an operation amount input to an input device that receives input for an operation to accelerate or decelerate a vehicle; determining a reference output of the vehicle's drive source based on the operation amount; determining whether at least two preset assist conditions are satisfied; determining an assist output increased from the reference output if at least two of the assist conditions are satisfied; controlling the drive source based on the assist output if at least two of the assist conditions are satisfied; and controlling the drive source based on the reference output if fewer than two of the assist conditions are satisfied.

[0207] According to the 19th aspect, the same effects as those of the vehicles relating to each aspect of the present disclosure can be obtained. Some and all of the control methods of the present disclosure may be implemented by, for example, a CPU, LSI or other circuits, an IC card or a standalone module. Multiple elements included in the control methods of the present disclosure may be implemented by one device or by two or more devices sharing the responsibility of implementation.

[0208] This disclosure may also be a computer program that causes a computer to execute a control method relating to each aspect of this disclosure. Such a computer program can have the same effects as a control method relating to each aspect of this disclosure. The computer program may be, for example, a program recorded on a non-temporary, tangible, computer-readable storage medium, and may be configured to be read from the storage medium using a drive device for the storage medium and installed on a computer. The computer program may be, for example, a program that can be distributed via a transmission medium such as the Internet, and may be configured to be downloaded and installed on a computer.

[0209] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs, conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0210] All ordinal numbers, quantities, and other figures used herein are illustrative to illustrate the technology of this disclosure, and this disclosure is not limited to such illustrative figures. The connections between components are illustrative to illustrate the technology of this disclosure, and the connections that realize the functions of this disclosure are not limited to these.

[0211] This disclosure can be implemented in various ways without departing from the scope of its essential features, and the scope of this disclosure is defined more by the appended claims than by the description in the specification; therefore, exemplary embodiments and modifications are illustrative and not limiting. All modifications within the claims and their scope, or equivalents within the claims and their scope, are intended to be encompassed by the claims. [Explanation of Symbols]

[0212] 1 vehicle 10 wheels 20. Drive source 21 Internal Combustion Engine 22 Rotating Electric Machines 30 Drive structure 32 transmission 32a Input axis 32d Transmission Actuator 41. Throttle Grip (First Input Device) 42 Shift control unit (second input unit) 50 Control circuits 109 batteries 128 Temperature Sensor

Claims

1. It is a vehicle, Wheels and, A drive source that drives the aforementioned wheels, A first input device that receives input for an operation to accelerate the vehicle, The system includes a control circuit that controls the drive source based on an input variable received by the first input device, The aforementioned control circuit is Determining a reference output which is the output of the drive source based on the manipulated amount, To determine whether at least two pre-set assist conditions are met, When at least two of the above assist conditions are satisfied, assist control is performed to control the driving source based on the assist output increased from the reference output, If there are fewer than two of the aforementioned assist conditions that are satisfied, normal control is performed to control the driving power source based on the reference output, A vehicle configured to perform the following actions.

2. The at least two assist conditions include a first assist condition relating to an operation to accelerate the vehicle and a second assist condition relating to the state of the vehicle. The vehicle according to claim 1.

3. The control circuit executes the assist control when the first assist condition and the second assist condition are satisfied. The vehicle according to claim 2.

4. The at least two of the above assist conditions include the condition that the amount of change in the manipulated variable is greater than or equal to a threshold that varies according to the manipulated variable. The vehicle according to claim 1.

5. The threshold value changes such that it becomes smaller as the manipulated variable increases. The vehicle according to claim 4.

6. The amount of change in the manipulated variable is the amount of change in the manipulated variable at a second timing that occurs after the first timing, relative to the manipulated variable at the first timing. The threshold corresponds to the manipulated amount at the first timing. The vehicle according to claim 5.

7. The aforementioned drive source includes an internal combustion engine and a rotating electric machine. The control circuit is configured to increase the output of both the internal combustion engine and the rotating electric machine from the respective reference output of the internal combustion engine and the rotating electric machine in the assist control. The vehicle according to any one of claims 1 to 4.

8. The vehicle further comprises a transmission that transmits power generated by the aforementioned drive source to the wheels. The control circuit is configured to determine an additional output based on the reduction ratio selected by the transmission, the manipulated amount, and the rotational speed of the drive source, and to determine the assist output by adding the additional output to the reference output. The vehicle according to any one of claims 1 to 4.

9. The control circuit is configured to cancel the assist control if the determined additional output is zero during the execution of the assist control. The vehicle according to claim 8.

10. The vehicle further comprises a transmission that transmits power generated by the aforementioned drive source to the wheels. The at least two assist conditions include the condition that the reduction ratio selected by the transmission is less than or equal to a preset reduction ratio. The vehicle according to any one of claims 1 to 4.

11. The aforementioned drive source includes an internal combustion engine and a rotating electric machine. The vehicle further comprises a drive structure connected to the internal combustion engine and the rotating electric machine so as to transmit power generated by the internal combustion engine and the rotating electric machine, and which transmits power supplied from the internal combustion engine and the rotating electric machine to the wheels. The drive structure includes an input shaft through which power generated by the internal combustion engine and the rotating electric machine is transmitted. The at least two assist conditions include the condition that the rotational speed of the input shaft is less than a preset first rotational speed. The vehicle according to any one of claims 1 to 4.

12. The aforementioned drive source includes an internal combustion engine and a rotating electric machine. The vehicle further comprises a drive structure connected to the internal combustion engine and the rotating electric machine so as to transmit power generated by the internal combustion engine and the rotating electric machine, and which transmits power supplied from the internal combustion engine and the rotating electric machine to the wheels. The at least two assist conditions include the condition that the drive structure is in a state in which it transmits the power generated by the internal combustion engine to the wheels. The vehicle according to any one of claims 1 to 4.

13. The aforementioned drive source includes an internal combustion engine and a rotating electric machine. The aforementioned vehicle is A battery electrically connected to the aforementioned rotating electric machine, The system further includes a temperature sensor for detecting the temperature of the battery, The at least two assist conditions include the condition that the temperature of the battery detected by the temperature sensor is less than or equal to a preset first temperature. The vehicle according to any one of claims 1 to 4.

14. A transmission that transmits power generated by the aforementioned drive source to the wheels, A second input device that receives input for an operation to specify the reduction ratio selected by the transmission, The transmission further comprises a transmission actuator that changes the reduction ratio selected by the transmission, The aforementioned control circuit is The system selectively performs control in manual and automatic shift modes. In the automatic transmission mode, the transmission actuator is controlled regardless of the operation input to the second input device. In the manual shift mode, the transmission is operated to change the reduction ratio according to the reduction ratio specified in the second input. The at least two assist conditions include the condition that the automatic transmission mode is in operation. The vehicle according to any one of claims 1 to 4.

15. The control circuit is configured to release the assist control if, during the execution of the assist control, at least one of the assist conditions that is being satisfied is no longer satisfied. The vehicle according to any one of claims 1 to 4.

16. The control circuit is configured to release the assist control if the manipulated amount falls to a preset first manipulated amount or less while the assist control is being executed. The vehicle according to any one of claims 1 to 4.

17. The vehicle further comprises a transmission that transmits power generated by the aforementioned drive source to the wheels. The control circuit is configured to cancel the assist control if the reduction ratio selected in the transmission is changed while the assist control is being executed. The vehicle according to any one of claims 1 to 4.

18. The aforementioned control circuit is When the assist control is started, the output of the driving source is increased from the reference output to the assist output at the first speed. When the assist control that is currently running is released, the system is configured to reduce the output of the drive source from the assist output to the reference output at a second speed. The magnitude of the first velocity is greater than the magnitude of the second velocity. The vehicle according to any one of claims 1 to 4.

19. To acquire information on the amount of operation input to an input device that receives input for accelerating or decelerating a vehicle, Based on the aforementioned manipulated quantity, the reference output of the vehicle's drive source is determined, To determine whether at least two pre-set assist conditions are met, When at least two of the above assist conditions are satisfied, the assist output is determined to be increased from the reference output, When at least two of the above assist conditions are satisfied, the driving source is controlled based on the assist output, If there are fewer than two of the aforementioned assist conditions that are satisfied, the driving power source is controlled based on the reference output, A method for controlling a vehicle, including the control of a vehicle.

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