Motor Output Control Method

Abstract

The present invention provides a method for controlling motor output in an electric motorcycle equipped with a stepped transmission that can be manually operated by a rider, wherein the output is changed upon deviating from a range of satisfactory motor efficiency, and the rider is prompted to perform a shift operation.　The method for controlling motor output of the present disclosure is a method for controlling the motor output of an electric motorcycle (1) equipped with a stepped transmission (20), and is characterized by comprising a required output calculation step (SA1) for calculating a required output, a determination step (SA2) for determining whether or not the required output is included in a designated area (82) of satisfactory motor efficiency, and an output control step (SA3) for controlling a motor (10) to output a motor output changed from the required output when the required output is not included in the designated area (82).

Description

Technical Field

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

Background Art

[0002] In saddle-type vehicles such as motorcycles, there is a great attraction in that the rider can directly convey their intentions to the vehicle and ride as if it were a part of their body. For conventional saddle-type vehicles driven by internal combustion engines, the operation targets include throttle opening / closing adjustment by an accelerator grip, braking, and stepped shifting involving clutch operation, which have enabled the rider to ride freely. Due to the increasing interest in environmental issues in recent years, electric motorcycles driven by electric motors have been developed for saddle-type vehicles. Among them, electric motorcycles provided with a clutch mechanism for cutting off between the motor and the gear train have also been disclosed (see, for example, International Publication No. 2014-102869).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The motor has a limited range of rotational speed and torque at which it can operate efficiently. However, in the case of an electric motorcycle using the motor as a drive source, since the motor can output a certain power, it is difficult for the rider to recognize the shifting timing for efficient operation when accelerating or decelerating. The present invention provides a motor output control method for an electric motorcycle equipped with a stepped transmission capable of manual operation by the rider, which changes the output when deviating from the region of good motor efficiency and prompts the rider to perform a shift operation.

Means for Solving the Problem

[0005] One aspect of the present invention is a method for controlling the motor output of an electric two-wheeler equipped with a stepped transmission, the method including a required output calculation step of calculating a required output, and determining whether the required output is included in a specified region of motor efficiency predetermined as a high region of a determination step, and an output control step of controlling the motor to output a motor output changed from the required output when the required output is not included in the specified region having, the output control step includes a shift-up determination step of determining whether the required output is included in a shift-up recommended region that should prompt a shift-up, and an output reduction step of reducing the motor output every time a predetermined time elapses when it is determined that the required output is included in the shift-up recommended region which is a motor output control method characterized by the above. Another aspect of the present invention is a method for controlling the motor output of an electric two-wheeler equipped with a stepped transmission, comprising a required output calculation step of calculating a required output, a determination step of determining whether the required output is included in a designated region predetermined as a region with high motor efficiency, and an output control step of controlling the motor to output a motor output changed from the required output when the required output is not included in the designated region. The output control step includes a downshift determination step of determining whether the required output is included in a downshift recommended region that should prompt a downshift, and a motor output increase step of increasing the motor output within a predetermined range when it is determined in the downshift determination step that the required output is included in the downshift recommended region. A motor output control method characterized by this is provided

Advantages of the Invention

[0006] According to one aspect of the present invention, it is possible to provide a motor output control method that makes it easy for a passenger to recognize the shift timing for high-efficiency motor operation.

Brief Description of the Drawings

[0007]

Figure 1

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Figure 7

Embodiments for Carrying Out the Invention

[0008] [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, directions such as front, rear, left, and right are the same as those in the vehicle described below unless otherwise specified. Also, arrows FR indicating the front of the vehicle and arrow UP indicating the upper part of the vehicle are shown at appropriate positions in the drawings used in the following description. In this specification, an electric motor is referred to as a motor.

[0009] FIG. 1 is a left side view of a saddle-riding type vehicle (electric two-wheeler) 1. The electric two-wheeler 1 of the present embodiment is an electric two-wheeler equipped with a motor instead of an internal combustion engine such as a gasoline engine as a power unit. Similar to a motorcycle driven by an internal combustion engine, the electric two-wheeler 1 includes an operation system 2 for the occupant to control the electric two-wheeler 1, such as an accelerator grip, a clutch lever, and a shift pedal. The electric two-wheeler 1 includes a front wheel 3 as a steering wheel and a rear wheel 4 as a drive wheel. The rear wheel 4 is supported at the rear part of a swing arm (not shown) swingably supported by a vehicle body frame (not shown).

[0010] The electric two-wheeler 1 includes an ECU (Electronic Control Unit) 5 which is a control device for performing various controls, a motor 10 for generating driving force, and a battery 15 for storing electric power. The electric two-wheeler 1 includes a clutch 25 and a stepped transmission 20 in order to transmit the driving force P of the motor 10 to the rear wheel 4. The motor 10 and the stepped transmission 20 are controlled by an ECU 5 that performs control according to instructions to the operation system 2 by the occupant.

[0011] Specifically, the ECU 5 is a computer having a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory) in which a program is written, a RAM (Random Access Memory) for temporarily storing data, and the like. By the ECU 5, which is a computer, executing the program, various control means are executed. Instead of or in addition to the above ECU 5, all or part of the above ECU 5 can also be configured by hardware including one or more electronic circuit components.

[0012] 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 fixed to the vehicle body frame. The stepped transmission 20 is a power transmission mechanism that combines a plurality of gears to change the rotational speed. The clutch 25 is a device that is attached between the motor 10 and the stepped transmission 20 and transmits or cuts off the driving force P to the stepped transmission 20. The clutch 25 operates when the occupant operates a clutch lever (not shown).

[0013] FIG. 2 is a block diagram showing the configuration of the ECU 5 that realizes the motor output control method according to the present embodiment. The ECU 5 is connected to an accelerator operation amount detection means 50 that detects the accelerator operation amount. The ECU 5 is connected to a motor rotation speed detection means for detecting the motor rotation speed of the motor 10 step and and a shift position detection means 60 that detects the shift position of the stepped transmission 20.

[0014] The ECU 5 includes a detection information acquisition means 23 that acquires information detected by various detection means. The ECU 5 also includes an arithmetic means 26 that performs an operation for output control based on the acquired information. The ECU 5 includes a determination means 27 that determines whether the output is within a specified area that is an output area with good motor efficiency, as will be described later. The operation of the determination means 27 will be described later. The ECU 5 includes an output control means for performing output control 29 . Each operation will be described later. The ECU 5 also includes a storage means 31 that stores programs and data for realizing various means, as well as a specified area, a shift-up threshold value, and a shift-down threshold value, which will be described later. The storage means 31 is realized by a storage device such as an SSD (Solid State Drive). The detection information acquisition means 23 is realized by an interface circuit or the like. The arithmetic means 26, the determination means 27, and the output control means 29 are realized by the ECU 5 executing the programs stored in the storage means 31 .

[0015] FIG. 3 is a flowchart of general output control in the electric two-wheeler 1. First, the accelerator operation amount detection means 50 detects the accelerator operation amount by the occupant (step TA1). Specifically, the throttle opening degree equivalent to that of an internal combustion engine is detected from the rotation angle of the accelerator grip or the like. Next, the ECU 5 causes the detection information acquisition means 23 to acquire the accelerator operation amount from the accelerator operation amount detection means 50. The calculation means 26 converts the accelerator operation amount into a required output (step TA2). Next, the calculation means calculates the motor output actually output from the required output (step TA3). The motor is driven with the motor output as a corresponding current value (step TA4). As a result, an output based on the required output is made from the motor 10 (step TA5).

[0016] FIG. 4 is a schematic diagram of motor output characteristics showing a specified region 82 with high motor efficiency. The horizontal axis represents the motor speed, and the vertical axis represents the motor output. As the motor output characteristics 85 at no load, an example is given in which the torque amount is constant regardless of the motor speed from 0 rpm to about 6500 rpm. The specified region 82, which is the region where the motor operates with high efficiency, is indicated by hatching. If the output of the electric two-wheeler 1 is within this specified region 82, it is possible to travel with high efficiency, that is, with good "fuel efficiency". FIG. 4 also shows a downshift threshold 90 and an upshift threshold 100. The explanations of the downshift threshold 90 and the upshift threshold 100 will be described later.

[0017] FIG. 5 is a flowchart of the motor output control method according to the present embodiment. First, the arithmetic means 26 of the ECU 5 estimates the motor speed and torque from the accelerator operation amount acquired from the accelerator operation amount detection means 50 and the shift of the stepped transmission 20 detected by the shift position detection means 60, and calculates the required output required by the occupant (step SA1: required output calculation step). Next, the determination means 27 of the ECU 5 determines whether or not the required output is included in the specified region 82 where the motor efficiency is good (step SA2: determination step). If the required output is not included in the specified region 82 (step SA2: NO), the ECU 5 does not output the value of the required output as it is as the motor output, but performs a process of changing the motor output for change control from the required output (step SA3: output control step). Then, according to the changed motor output, the ECU 5 controls the motor 10 to perform the motor output (step SA4). If the determination means 27 determines that the required output is included in the specified region 82 where the motor efficiency is good, the ECU 5 controls the motor 10 to output the value of the required output as it is as the motor output, and performs the motor output (step SA2: YES).

[0018] In other words, the motor output control method according to the present embodiment includes a required output calculation step (SA1) for calculating a required output, a determination step (SA2) for determining whether or not the required output is included in a specified region 82 where the motor efficiency is good, and an output control step (SA3) for controlling the motor 10 to output a motor output changed from the required output when the required output is not included in the specified region 82.

[0019] FIG. 6 is a flowchart of the motor output change process. First, the determination means 27 determines whether the required output is included in the upshift recommended area (step SB1). Here, the upshift recommended area is an output area where it is appropriate to perform an upshift in the stepped transmission 20 for efficient operation. In FIG. 4, it is the area on the higher motor rotation speed side from the line of the upshift threshold value 100 and not included in the designated area 82. When the required output is included in the upshift recommended area (step SB1: YES), the output control means 29 performs control to reduce the motor output every time a predetermined time elapses (step SB2). By performing such control, the occupant can recognize the timing of the upshift. Next, the determination means 27 determines whether the required output is included in the downshift recommended area (step SB3). Here, the downshift recommended area is an output area where it is appropriate to perform a downshift in the stepped transmission 20 for efficient operation. In FIG. 4, it is the area on the lower motor rotation speed side from the line of the downshift threshold value 90 and not included in the designated area 82. When the required output is included in the downshift recommended area (step SB3: YES), the output control means 29 performs control to increase the motor output within a predetermined range (step SB4). By performing such control, the occupant can recognize the timing of the downshift. When the required output is not included in the upshift recommended area (step SB1: NO), the process proceeds to step SB3. When the required output is not included in the downshift recommended area (step SB3: NO), the motor output change process is exited.

[0020] FIG. 7 is an explanatory diagram showing the relationship between the change in output characteristics due to a shift change and a specified region with high motor efficiency. For example, when the required output is in state A at the 2nd gear shift position, it is outside the specified region 82 with good motor efficiency, and a shift up is desirable. In other words, in FIG. 7, state A is included in the region on the higher motor rotation speed side than the line of the shift up threshold 100 and not included in the specified region 82. In this case, according to the motor output control method of the present embodiment, by the output control means 29 performing control to reduce the motor output, it is possible to make the occupant aware that an inefficient operation is being performed and to prompt a shift up. Also, when the required output is in state B at the 5th gear shift position, it is outside the specified region 82 with good motor efficiency, and a shift down is desirable. In other words, in FIG. 7, state B is included in the region on the lower motor rotation speed side than the line of the shift down threshold 90 and not included in the specified region 82. In this case, according to the motor output control method of the present embodiment, by the output control means 29 performing control to increase the motor output, it is possible to make the occupant aware that an inefficient operation is being performed and to prompt a shift down.

[0021] [Configuration Supported by the Above Embodiment] The above embodiment supports the following configuration.

[0022] (Configuration 1) A method for controlling the motor output of an electric two-wheeler equipped with a stepped transmission, comprising a required output calculation step for calculating a required output, a determination step for determining whether the required output is included in a specified region with good motor efficiency, and an output control step for controlling the motor to output a motor output changed from the required output when the required output is not included in the specified region. According to such a configuration, when the required output is outside the region with good motor efficiency, it is possible to make the occupant recognize that the output is not appropriate and to prompt the occupant to perform a shift operation. Therefore, it has an excellent effect of enabling operation within a region with high motor efficiency.

[0023] (Configuration 2) It has a shift-up determination step of determining whether or not the required output is included in a shift-up recommended area where a shift-up should be promoted. In the shift-up determination step, when it is determined that the required output is included in the shift-up recommended area, the output control step has an output reduction step of reducing the motor output every time a predetermined time elapses. The motor output control method according to Configuration 1, characterized in that. According to such a configuration, when it is determined that a shift-up is necessary to operate with high motor efficiency, the motor output is gradually suppressed, so that the shift-up can be promoted without the driver feeling excessive discomfort, and the driver can be made to drive in an efficient area, which has an excellent effect.

[0024] (Configuration 3) It has a shift-down determination step of determining whether or not the output is included in a shift-down recommended area where a shift-down should be promoted. In the shift-down determination step, when it is determined that the required output is included in the shift-down recommended area, the output control step has a motor output increase step of increasing the motor output within a predetermined range. The motor output control method according to Configuration 1 or Configuration 2, characterized in that. requirement According to such a configuration, when it is determined that a shift-down is necessary to operate with high motor efficiency, it is easy for the driver to recognize that the motor output does not catch up with the required output, so that the driver can be prompted to shift down, and the driver can be made to drive in an efficient area, which has an excellent effect. It should be noted that the above embodiment shows one aspect to which the present invention is applied, and the present invention is not limited to the above embodiment.

[0025] The above embodiment shows one aspect to which the present invention is applied, and the present invention is not limited to the above embodiment.

[0026] For example, the step units of the operations shown in FIGS. 3, 5, and 6 are divided according to the main processing content in order to facilitate the understanding of the control method of the electric two-wheeler, and the present invention is not limited by the way of dividing the processing units or the names. According to the processing content, it may be further divided into more step units. Also, one step unit may be divided to include more processes. Further, the order of the steps may be appropriately changed within a range not hindering the gist of the present invention.

Explanation of Signs

[0027] 1 Saddle-riding type vehicle (electric two-wheeler) 10 Motor 20 Step transmission 82 Designated area

Claims

1. A method for controlling the motor output of an electric two-wheeler (1) equipped with a stepped transmission (20), comprising: a required output calculation step (SA1) for calculating a required output; a determination step (SA2) for determining whether the required output is included in a designated area (82) previously defined as an area with high motor efficiency; an output control step (SA3) for controlling the motor (10) to output a motor output changed from the required output when the required output is not included in the designated area (82); and the output control step (SA2) includes: a downshift determination step (SB1) for determining whether the required output is included in a downshift recommended area where upshifting should be promoted; an output reduction step (SB2) for reducing the motor output every time a predetermined time elapses when it is determined in the downshift determination step (SB1) that the required output is included in the downshift recommended area; A motor output control method, characterized by including the above.

2. A method for controlling the motor output of an electric two-wheeler (1) equipped with a stepped transmission (20), comprising: a required output calculation step (SA1) for calculating a required output; a determination step (SA2) for determining whether the required output is included in a designated area (82) previously defined as an area with high motor efficiency; an output control step (SA3) for controlling the motor (10) to output a motor output changed from the required output when the required output is not included in the designated area (82); and the output control step (SA2) includes: a downshift determination step (SB3) for determining whether the required output is included in a downshift recommended area where downshifting should be promoted; a motor output increase step (SB4) for increasing the motor output within a predetermined range when it is determined in the downshift determination step (SB3) that the required output is included in the downshift recommended area; A motor output control method, characterized by including the above.

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