METHOD FOR CONTROLLING AN ENGINE OUTPUT

Abstract

The present invention provides a method for controlling the motor output of an electric motorcycle with a stepped transmission which can be manually operated by an occupant, wherein the method comprises changing the output when the output deviates from a range with satisfactory motor efficiency, and prompting the occupant to perform a shifting operation. A method for controlling a motor output according to the present disclosure is a method for controlling a motor output of an electric motorcycle (1) which includes a stepped transmission (20), wherein the method comprises: an output request calculation step (SA1) for calculating a requested output; a determination step (SA2) for determining whether the requested output is contained within a designated range (82) with satisfactory motor efficiency; and an output control step (SA3) for controlling a motor (10) to output a motor output different from the requested output if the requested output is not contained within the designated range (82).

Description

Technical area

[0001] The present invention relates to a method for controlling an engine output. background

[0002] A saddle-seat vehicle, such as a motorcycle, is very attractive in that the occupant can transmit their intentions directly to the vehicle, allowing the occupant to drive the vehicle as if it were part of their body. In a conventional saddle-seat vehicle powered by an internal combustion engine, for example, the occupant can use a throttle to open or close the throttle, brake, and shift gears incrementally while simultaneously operating the clutch. The occupant can drive the vehicle freely during such operations.

[0003] Due to growing interest in environmental issues, electric motorcycles with electric motors that can also be used as saddle-seat vehicles have been developed in recent years. Such electric motorcycles have been described as an electric motorcycle equipped with a clutch mechanism that decouples a motor from a transmission (see, for example, WO 2014 / 102869 A). Citation listPatent literature

[0004] Patent literature 1: WO 2014 / 102869 A Summary of the inventionTechnical problem

[0005] The motor has a limited speed and torque range within which it can operate with high efficiency. However, with an electric motorcycle that uses a motor capable of constant output as its power source, it's difficult for a passenger to determine the timing of gear shifting for high-efficiency riding during acceleration or deceleration.

[0006] The present invention provides a method for controlling the engine output of an electric motorcycle having a stepped transmission manually operable by an occupant, the method comprising changing the output when the output deviates from a range of satisfactory engine efficiency and prompting the occupant to perform a gear shift. Solution to the problem

[0007] One aspect of the present invention provides a method for controlling a motor output of an electric motorcycle having a stepped transmission, the method comprising: an output request calculation step for calculating a requested output; a determination step for determining whether or not the requested output is included in a designated range with satisfactory motor efficiency; and an output control step for controlling a motor to output a motor output different from the requested output when the requested output is not included in the designated range.

[0008] This specification contains the entire contents of Japanese Patent Application No. 2022-054588 filed on March 29, 2022. Advantageous effects of the invention

[0009] According to one aspect of the present invention, it is possible to provide an engine output control method that makes it easy for an occupant to recognize a shift timing for high engine efficiency driving. Brief description of the drawings Fig. Figure 1 is a diagram showing the configuration of an electric motorcycle. Fig. 2 is a diagram showing a configuration for implementing a method for controlling an engine output according to an embodiment of the present invention. Fig. 3 is a flowchart of the output control in the electric motorcycle. Fig. Figure 4 is a schematic diagram of the engine output characteristics, showing a designated high engine efficiency area. Fig. 5 is a flowchart illustrating the method for controlling the motor output. Fig. Figure 6 is a flowchart illustrating the processing of engine output changes. Fig. 7 is an explanatory diagram showing the relationship between a change in output characteristics due to a shift change and a designated high engine efficiency region. Description of the embodiments[Embodiment]

[0010] An embodiment of the present invention will be described below with reference to the drawings. Note that directions such as front, rear, left, and right in the following description are the same as those for a vehicle described below unless otherwise specified. In addition, in the drawings used for the following description, an arrow FR indicating the front of a vehicle and an arrow UP indicating the top of the vehicle are shown at the corresponding positions. In this description, an electric motor is referred to as a motor.

[0011] Fig. 1 is a left side view of a saddle-seat vehicle (electric motorcycle) 1. The electric motorcycle 1 according to the present embodiment may be an electric motorcycle that includes a motor as a drive unit instead of an internal combustion engine such as a gasoline engine. Similar to a motorcycle powered by an internal combustion engine, the electric motorcycle 1 includes a throttle grip, a clutch lever, a shift pedal, and the like as an operating system 2 for a passenger to control the electric motorcycle 1. The electric motorcycle 1 includes a front wheel 3 that also serves as a steering wheel, and a rear wheel 4 that also serves as a drive wheel. The rear wheel 4 is supported by a rear part of a swing arm (not shown) pivotally mounted on a vehicle frame (not shown).

[0012] The electric motorcycle 1 includes an electronic control unit (ECU) 5, which is a control device for performing various types of controls, a motor 10 that generates driving power, and a battery 15 that stores electrical energy. The electric motorcycle 1 includes a clutch 25 and a step-up transmission 20 for transmitting a driving force P of the motor 10 to the rear wheel 4. The motor 10 and the step-up transmission 20 are controlled by the ECU 5, which performs the control according to an instruction from the driver to the actuation system 2.

[0013] Specifically, the ECU 5 is a computer that includes a processor such as a central processing unit (CPU), a read-only memory (ROM) in which a program is written, a random access memory (RAM) for temporarily storing data, and the like. The ECU 5, in the form of a computer, executes the program to implement various types of control devices. Instead of or in addition to the above ECU 5, hardware including one or more electronic circuit components may be used for all or part of the above ECU 5.

[0014] The motor 10 is a three-phase electric motor or the like. The battery 15 may be a lithium-ion battery or the like. The motor 10 and the battery 15 are mounted on the frame of the vehicle body. The stepped transmission 20 is a power transmission mechanism that changes the speed by combining multiple gears. The clutch 25 is a device installed between the motor 10 and the stepped transmission 20, which transmits or interrupts the driving force P to the stepped transmission 20. The passenger engages the clutch 25 by operating a clutch lever (not shown).

[0015] Fig. 2 is a block diagram showing a configuration of the ECU 5 for implementing the engine output control method according to the present embodiment. The ECU 5 is connected to a throttle operation amount detector 50 that detects a throttle operation amount. The ECU 5 is connected to an engine speed detector that detects the engine speed of the engine 10 and a gear position detector 60 that detects the gear position of the stepped transmission 20.

[0016] The ECU 5 includes an acquisition unit 23 for acquiring information detected by the various detectors. The ECU 5 also includes a calculation unit 26 that performs calculation to perform output control based on the acquired information. The ECU 5 includes a determination unit 27 that determines whether or not an output is included in a designated range constituting an output range with satisfactory engine efficiency, as described later. The operation of the determination unit 27 will be described later. The ECU 5 includes an output control unit 29 that performs output control. The operation of each unit will be described later.Furthermore, the ECU 5 includes a storage unit 31 storing programs and data for implementing various units, as well as a designated area, an upshift threshold, and a downshift threshold, which will be described later. The storage unit 31 is implemented by a storage device such as a solid-state drive (SSD). The above acquisition unit 23 for acquiring acquired information is implemented by an interface circuit or the like. The calculation unit 26, the determination unit 27, and the output control unit 29 are implemented by the ECU 5, which executes a program stored in the storage unit 35.

[0017] Fig. 3 is a flowchart illustrating conventional output control in the electric motorcycle 1. First, the throttle operation amount detector 50 detects a throttle operation amount by the passenger (step TA1). Specifically, the throttle operation amount detector 50 detects a throttle opening in an internal combustion engine based on the rotation angle of the throttle grip or the like. Next, the detected information acquisition unit 23 in the ECU 5 acquires the throttle operation amount from the throttle operation amount detector 50. The calculation unit 26 converts the throttle operation amount into a requested output (step TA2). Subsequently, the calculation unit calculates an actual motor output to be output from the requested output (step TA3). The motor is driven at a current value corresponding to the motor output (step TA4).As a result, the engine 10 performs an output based on the requested output (step TA5).

[0018] Fig. Figure 4 is a schematic diagram of the engine output characteristics, showing a designated high-efficiency engine region 82. The horizontal axis represents engine speed, and the vertical axis represents engine output. Fig. Figure 4 shows the engine output characteristic 85 at no load, an example in which the torque is constant regardless of the engine speed when the speed is between 0 and approximately 6500 rpm. The designated area 82, in which the engine operates with high efficiency, is shown hatched. When the output of the electric motorcycle 1 is within the designated area 82, the electric motorcycle 1 can operate with high efficiency, ie, with high "fuel efficiency." Fig. 4 also shows a downshift threshold 90 and an upshift threshold 100. The downshift threshold 90 and the upshift threshold 100 will be described later.

[0019] Fig. 5 is a flowchart illustrating the method for controlling engine output according to the present embodiment. First, the calculation unit 26 of the ECU 5 estimates the engine speed and torque from the throttle operation amount detected by the throttle operation amount detector 50, the shift of the stepped transmission 20 detected by the shift position detector 60, and the like, and calculates a requested output requested by the occupant (step SA1: output request calculation step). Next, the determination unit 27 of the ECU 5 determines whether or not the requested output is included in the designated high engine efficiency range 82 (step SA2: determination step).If the requested output is not included in the designated range 82 (step SA2: NO), the ECU 5 does not directly output the requested output value to the engine 10 as the engine output, but performs change control processing to change the engine output according to the requested output (step SA3: output control step). Then, the ECU 5 controls the engine 10 according to the changed engine output and performs the engine output (step SA4). If the determination unit 27 determines that the requested output is included in the high engine efficiency designated range 82, the ECU 5 controls the engine 10 so that the engine 10 directly outputs a value of the requested output as the engine output and performs the engine output (step SA2: YES).

[0020] In other words, the engine output control method according to the present embodiment includes: an output request calculation step (SA1) for calculating a requested output; a determination step (SA2) for determining whether or not the requested output is included in the designated range 82 with satisfactory engine efficiency; and an output control step (SA3) for controlling the engine 10 to output an engine output different from the requested output when the requested output is not included in the designated range 82.

[0021] Fig. Figure 6 is a flowchart showing the processing of engine output changes. First, the determination unit 27 determines whether the requested output is included in an upshift recommendation range (step SB1). In this case, the upshift recommendation range is an output range in which it is appropriate to upshift the stepped transmission 20 for efficient travel. Fig. 4, the upshift recommendation range is a range not included in the designated range 82 on the side where the engine speed is higher than the line indicating the upshift threshold 100. When the requested output is included in the upshift recommendation range (step SB1: YES), the output control unit 29 performs control to reduce the engine output every predetermined period (step SB2). By performing such control, the occupant can recognize the timing of the upshift.

[0022] Next, the determination unit 27 determines whether the requested output is included in a downshift recommendation range (step SB3). In this case, the downshift recommendation range is an output range in which it is appropriate to downshift the step transmission 20 for efficient driving. Fig. 4, the downshift recommendation range is a range not included in the designated range 82 on the side where the engine speed is lower than the line indicating the downshift threshold 90. When the requested output is within the downshift recommendation range (step SB3: YES), the output control unit 29 performs control to increase the engine output within a predetermined range (step SB4). By performing such control, the occupant can recognize the timing of the downshift.

[0023] If the requested output is not included in the upshift recommendation range (step SB1: NO), the process proceeds to step SB3, and if the requested output is not included in the downshift recommendation range (step SB3: NO), the engine output change process is terminated.

[0024] Fig. Figure 7 is an explanatory diagram illustrating the relationship between a change in output characteristics due to a shift and a designated high engine efficiency range. For example, when the requested output is in state A where the shift position is in second gear, the requested output is outside the designated range 82 with satisfactory engine efficiency, which is why an upshift is desirable. In other words, in Fig. 7, state A is included in a region not included in the designated region 82 on the side where the engine speed is higher with respect to the line indicating the upshift threshold 100. In this case, according to the engine output control method of the present embodiment, the output control unit 29 performs control to reduce the engine output, whereby the occupant may determine that he / she is driving inefficiently, and therefore the occupant may be prompted to upshift.

[0025] When the requested output is in a state B where the shift position is in fifth gear, the requested output is outside the designated range 82 with a satisfactory engine efficiency, which is why a downshift is desirable. In other words, in Fig. 7, state B is included in a region not included in the designated region 82 on the side where the engine speed is lower with respect to the line indicating the downshift threshold 90. In this case, according to the engine output control method of the present embodiment, the output control unit 29 performs control to increase the engine output, whereby the occupant may notice that he / she is driving inefficiently, and therefore the occupant may be prompted to downshift. [Configurations supported by the above embodiment]

[0026] The above embodiment supports the following configurations.

[0027] (Configuration 1) A method for controlling a motor output of an electric motorcycle having a stepped transmission, the method comprising: an output request calculation step for calculating a requested output; a determination step for determining whether or not the requested output is included in a designated range with satisfactory motor efficiency; and an output control step for controlling a motor to output a motor output different from the requested output when the requested output is not included in the designated range.

[0028] This configuration can alert the occupant that the output is inadequate and prompt the occupant to perform a gear shift when the requested output is outside a range of satisfactory engine efficiency. Therefore, this configuration achieves the highly beneficial effect of enabling driving in a high engine efficiency range.

[0029] (Configuration 2) The method for controlling an engine output according to Configuration 1, further comprising an upshift determining step of determining whether or not the requested output is included in an upshift recommendation range in which the upshift is to be recommended, wherein, when it is determined in the upshift determining step that the requested output is included in the upshift recommendation range, the output control step includes an output reducing step of reducing the engine output every predetermined period.

[0030] With this configuration, when it is determined that an upshift is necessary to achieve high-efficiency driving, the engine output is gradually reduced. Thus, this configuration achieves a highly beneficial effect, as it can prompt an occupant to upshift without giving them a strange feeling, allowing the occupant to drive with satisfactory efficiency.

[0031] (Configuration 3) The method for controlling an engine output according to Configuration 1 or 2, further including a downshift determining step of determining whether or not the requested output is included in a downshift recommendation range in which the downshift is to be recommended, wherein, when it is determined in the downshift determining step that the requested output is included in the downshift recommendation range, the output control step includes an engine output increasing step of increasing the engine output within a predetermined range.

[0032] With this configuration, when it is determined that a downshift is necessary to achieve high-efficiency driving, the occupant can easily detect that the engine output does not match the requested output. Thus, this configuration achieves a highly beneficial effect, as it is able to prompt the occupant to downshift and allows the occupant to drive with satisfactory efficiency.

[0033] It should be noted that the above embodiment represents one aspect to which the present invention is applied, and the present invention is not limited to the above embodiment.

[0034] For example, anyone who is in the Fig. 3, Fig. 5 and Fig.6, in order to more easily understand the control method for the electric motorcycle, the processes described above are divided into steps based on the details of the main processes. However, the present invention is not limited to how the process is divided into process units and the names of the process units. The process may be divided into a larger number of steps depending on the details of the processes. Furthermore, the process may be divided into steps such that each of the steps includes a larger number of processes. Furthermore, the order of the steps may be changed without departing from the gist of the present invention. [List of reference symbols] 1 saddle-seat vehicle (electric motorcycle) 10 Engine 20-step transmission 82 designated area QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2014 / 102869 A [0003, 0004] Japanese Patent Application No. 2022-054588

[0008]

Claims

[1] A method for controlling an engine output of an electric motorcycle (1) with a step transmission (20), the method characterized by is that it has: an output request calculation step (SA1) to calculate a requested output; a determination step (SA2) for determining whether or not the requested output is included in a designated range (82) with satisfactory engine efficiency; and an output control step (SA3) for controlling a motor (10) to output a motor output different from the requested output when the requested output is not in the designated range (82). [2] The method for controlling an engine output according to claim 1, further comprising an upshift determining step (SB1) for determining whether or not the requested output is included in an upshift recommendation range in which the upshift is to be recommended, wherein, if it is determined in the upshift determination step (SB1) that the requested output is included in the upshift recommendation range, the output control step comprises an output reducing step (SB2) for reducing the engine output every predetermined period of time. [3] The method for controlling an engine output according to claim 1 or 2, further comprising a downshift determining step (SB3) for determining whether or not the requested output is included in a downshift recommendation range in which the downshift is to be recommended, wherein, if it is determined in the downshift determination step (SB3) that the requested output is included in the downshift recommendation range, the output control step (SA3) comprises an engine output increasing step (SB4) for increasing the engine output within a predetermined range.

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