TWI766369B - Gear shifting system and method for electric locomotive - Google Patents

Abstract

The present invention is a gear shifting system and method for an electric locomotive. The gear shifting system for an electric locomotive includes a throttle position sensor (TPS), a motor controller and a vehicle controller. The throttle position sensing The device senses a throttle opening to generate a throttle opening signal, the motor controller receives a motor speed signal representing the actual speed of a motor of the motor, wherein the vehicle controller receives the accelerator opening signal and the motor the speed signal and calculates an average accelerator change rate according to the accelerator opening signal. When the electric locomotive is in the second gear and the average accelerator change rate meets a preset threshold value in an acceleration correction condition, the vehicle controller outputs a change The gear command is used to control the electric scooter from the second gear to the first gear, so that the electric scooter has better acceleration performance.

Description

Gear shifting system and method for electric locomotive

A gear shifting technology for an electric scooter, especially a system and method that can automatically switch the electric scooter to the first gear or the second gear according to the current operating state of the electric scooter.

The power source of the electric locomotive comes from the battery loaded in the locomotive, and the electric motor of the battery is used to drive the motor to rotate to drive the wheels to rotate, so that the locomotive moves forward. Generally, the electric locomotive is powered by a fixed gear ratio. In other words, the running speed of the electric locomotive is completely determined by the rotational speed of the motor. When the rotational speed of the motor is higher, the driving speed is faster, and conversely, the driving speed is slower when the rotational speed of the motor is lower.

When encountering different driving conditions such as driving on flat ground, climbing sections or starting after parking, due to the lack of shifting mechanism of electric scooters, it is difficult to adjust the power output corresponding to the torque required for special driving conditions. For the electric locomotive with the gear shifting function, under the condition of not changing the maximum output power of the motor, due to the limitation of the fixed gear ratio, when the electric locomotive pursues the acceleration performance, the upper limit of the maximum speed will be lower; When the maximum speed limit is reached, it will lead to poor acceleration performance. If the rider's experience is to be considered again, the shifting mechanism of the electric scooter will be more complicated.

[Technical problem to be solved by the invention]

In order to overcome the difficulty of considering the rider's experience in the existing electric scooter and provide an appropriate automatic shifting mechanism, the present invention provides a gear shifting system for an electric scooter, so as to provide an appropriate gear changing function for the electric scooter.

[Technical means to solve problems]

According to the preferred technical means of the present invention, the present invention provides a gear shifting system for an electric locomotive. The electric locomotive includes a motor, a shifting motor and a gearbox, and the electric locomotive can alternate between the first gear and the second gear. To switch gears, the gear shifting system of this electric scooter includes:

The throttle valve position sensor senses a throttle opening to generate a throttle opening signal;

a motor controller, receiving a motor speed signal, the motor speed signal representing an actual speed of a motor of the motor;

a vehicle controller, electrically connected to the throttle position sensor and the motor controller, for receiving the accelerator opening signal and the motor speed signal, the vehicle controller calculates an average value according to the accelerator opening signal Throttle change rate;

Wherein, the vehicle controller is preset with an acceleration correction condition, and the acceleration correction condition includes judging whether the average throttle change rate is greater than or equal to a preset threshold value, when the electric locomotive is in the second gear, if the vehicle controller It is judged that the average throttle change rate is greater than or equal to the preset threshold value, and a shift command is output to the shift motor to control the gear of the electric scooter to switch to the first gear.

According to the preferred technical means of the present invention, the present invention provides a gear shifting method of an electric scooter, the electric locomotive includes a motor and can alternately switch gears between the first gear and the second gear, and the automatic shifting method of the electric locomotive Contains:

Sensing a throttle opening and a motor actual speed of the electric locomotive to generate a throttle opening signal and a motor speed signal respectively;

Calculate an average throttle change rate according to the throttle opening;

Presetting an acceleration correction condition, wherein the acceleration correction condition includes determining whether the average throttle change rate is greater than or equal to a predetermined threshold value;

When the electric scooter is in the second gear, determine whether the average throttle change rate is greater than or equal to the preset threshold value, and if so, output a shift command to control the electric scooter to switch the gear to the first gear.

[Effect of invention]

With the gear shifting system and method of the present invention, when the electric scooter is in the second gear, as the rider urgently pushes the throttle handle to make the average throttle change rate meet the acceleration correction condition, the vehicle controller can issue a shift command , so that the electric locomotive is converted from the second gear to the first gear, so that the electric locomotive has a high acceleration performance.

Please refer to FIG. 1, which is a first embodiment of a gear shifting system for an electric locomotive, including: a throttle valve position sensor 10, a motor controller 20, and a vehicle controller 30; the electric locomotive may include a Shift motor 50, a gearbox 60, a throttle handle 70 and a motor 80, wherein, the electric scooter has a first gear and a second gear, when the electric scooter runs in the first gear, it has better acceleration performance, riding Passengers can experience a more obvious sense of acceleration; when the electric scooter is driving in the second gear, there will be a higher maximum speed limit.

The throttle position sensor 10 (Throttle Position Sensor, TPS, or throttle opening sensor) senses a throttle opening of the electric scooter, and outputs a throttle opening signal T according to the throttle opening, wherein, The throttle opening of the electric locomotive can be controlled by the throttle handle 70 electrically connected to the throttle position sensor 10 , and the rotation amplitude of the throttle handle 70 is positively correlated with the throttle opening, which is a percentage (%) means that when the driver turns the accelerator handle 70 to a greater extent, the percentage of the accelerator opening degree is higher.

The motor controller 20 is electrically connected to the motor 80 of the electric locomotive to receive a motor speed signal M. The motor 80 is used to provide the power source of the whole vehicle, and a Hall sensor 81 is arranged on the motor 80 . The Hall sensor 81 is used to sense an actual rotational speed (rpm) of the motor 80 , and then according to the The actual speed of the motor generates the motor speed signal M.

The vehicle controller 30 (VCU) is electrically connected to the throttle position sensor 10 and the motor controller 20 to receive the accelerator opening signal T and the motor rotational speed signal M, and transmit the accelerator opening signal T to the motor controller 20 . The motor speed signal M is transmitted to the rear end. The vehicle controller 30 may be further connected to a battery management system (BMS) 100 of the electric scooter, and obtain data such as battery temperature and battery residual power of the electric scooter from the battery management system 100 .

The vehicle controller 30 compares the received electric vehicle information with preset shifting conditions in real time to determine whether to automatically shift the current gear of the electric vehicle, and if it is determined that shifting is required, it outputs a shifting instruction, The shift determination process of the vehicle controller 30 will be further described in detail below. The electric vehicle information may include the accelerator opening signal T and the motor rotational speed signal M, and the accelerator opening and the motor actual rotational speed of the electric scooter are obtained according to the accelerator opening signal T and the motor rotational speed signal M, or further Contains the battery temperature of the electric scooter, the remaining battery power, and the like.

The shift motor 50 is electrically connected to the vehicle controller 30 to receive the shift command and control the gearbox 60 to shift according to the shift command, so that the electric scooter can alternate between the first gear and the second gear Switch gears.

The gearbox 60 may include a lever 61 , a clutch 62 and a gear set 63 . When the shift motor 50 receives the shift command, the shift motor 50 drives a cable to pull the actuating rod 61 , and controls the clutch 62 through the actuating rod 61 , and then the clutch 62 drives the gear set 63 to switch For different gear ratios, the electric scooter is in the first gear state when the clutch 62 is opened, and the electric scooter is in the second gear state when the clutch 62 is clamped.

Referring to FIG. 2 , the gear shifting method of the present invention is executed through the electric vehicle gear shifting system of FIG. 1 , and the steps include:

S101: The vehicle controller 30 obtains the electric vehicle information, the electric vehicle information includes the accelerator opening signal T, the motor speed signal M, and further includes the battery temperature and the battery residual power of the electric vehicle.

S102: Determine the acceleration correction condition, wherein the acceleration correction condition includes: (a) whether the average throttle change rate is greater than or equal to a preset threshold value, and if it is greater than or equal to the preset threshold value, then determine that the acceleration correction condition is established. Please refer to FIG. 3 , the calculation method of the average throttle change rate is to capture the unit time change of the throttle opening of a plurality of strokes, and then calculate the average value of the change of the plurality of strokes, for example, at time points t1, t2, The throttle opening degrees captured by t3 are 10%, 20%, and 30%, respectively, and the unit time changes Δ0, Δ1, and Δ2 of the three accelerator opening degrees are: Δ0=10-0=10; Δ1=20 -10=10; Δ2=30-20=10, so the average throttle change rate is the average of the three changes (10+10+10)/3=10%. If the preset threshold value is set to 10%, in this example, the calculated average throttle change rate is 10%, that is, it is determined that the acceleration correction condition is satisfied.

In another embodiment, the acceleration correction condition may be a composite condition, that is, in addition to the above condition (a), add: (b) whether the battery temperature is lower than a temperature threshold, such as 55°C; (c) Whether the remaining battery power is greater than or equal to a power threshold, such as 10%; (d) whether the actual speed of the motor is less than or equal to a speed threshold, such as 5000rpm. When the acceleration correction condition is a compound condition, when all conditions (a), (b), (c), and (d) are satisfied, it is judged that the acceleration correction condition is established; on the contrary, as long as there is any one of the conditions If not, for example, the battery temperature is higher than the temperature threshold, or the battery residual power is lower than the power threshold, or the actual speed of the motor is greater than the speed threshold, then it will be judged that the acceleration correction condition does not hold. Because a higher power needs to be drawn from the battery in the first gear, judging the battery temperature and the remaining battery power can improve the riding safety of the electric scooter and avoid accidents caused by excessive battery temperature or insufficient power. The purpose of additionally judging the actual speed of the motor is to avoid returning to the second gear due to the actual speed of the motor reaching the second gear switching condition after returning to the first gear due to the acceleration correction mechanism, resulting in frequent gear switching.

S103: Determine the state of an acceleration correction flag register according to the judgment result of the acceleration correction condition. In this embodiment, after the acceleration correction condition is determined to be established, the state of the acceleration correction flag register is set to a first state, for example, set to "1" to represent the first state; When it is judged that the correction condition is not established, the state of the acceleration correction flag register is set to a second state. For example, clearing the acceleration correction flag register to "0" represents the second state. The acceleration correction flag register may be a flag register in the vehicle controller 30 .

S104: It is judged that the current gear state of the electric scooter is in the first gear or the second gear, if it is in the second gear, execute a downshift determination process 200; if it is in the first gear, execute an upshift determination process 300. The downshift determination process 200 includes the following steps:

S201: Determine whether the state of the acceleration correction flag is the first state or the second state.

S202: When the state of the acceleration correction flag is the first state (for example, set to "1"), the vehicle controller 30 outputs a shift command to the shift motor 50 to lower the gear from the second gear to First gear; this acceleration and downshift operation can occur when the electric motorcycle is already in second gear, and the rider quickly turns the accelerator handle to satisfy the acceleration compensation condition in order to enjoy a more pronounced acceleration feeling, so that the electric motorcycle can be quickly shifted to the first gear .

S203: When the state of the acceleration correction flag is the second state (for example, cleared to "0"), the vehicle controller 30 according to the accelerator opening of the electric locomotive and the actual speed of the motor, as shown in FIG. 4 Compared with a downshift critical curve 41 of , it is judged whether the downshift condition is met.

S204: If it is determined that the downshift condition is met, the vehicle controller 30 outputs a shift command to the shift motor 50 to downshift the gear from the second gear to the first gear. This general downshift operation can occur when the electric scooter is already in second gear, and the rider gradually loosens the accelerator handle or brakes, causing the actual speed of the motor to decrease, causing the electric scooter to shift to first gear.

In the upshift determination process 300, the first embodiment of the method shown in FIG. 2 includes the following steps:

S301 : The vehicle controller 30 compares with a normal upshift threshold curve 42 shown in FIG. 4 according to the accelerator opening of the electric locomotive and the actual speed of the motor, and determines whether the upshift condition is met.

S302 : If it is determined that the upshift condition is met, the vehicle controller 30 outputs a shift command to the shift motor 50 to upgrade the gear position from the first gear to the second gear.

Referring to FIG. 4 , the downshift critical curve 41 used in the above step S203 includes a plurality of downshift critical points jointly defined by the motor speed and the accelerator opening, and the downshift critical curve 41 is composed of adjacent groups of The two downshift critical points are obtained by arithmetic difference method. Similarly, the normal upshift threshold curve 42 in the above step S301 includes a plurality of upshift threshold points jointly defined by the motor speed and the accelerator opening, and the normal upshift threshold curve 42 is composed of two adjacent groups of each other. This upshift critical point is obtained by arithmetic difference method. In the figure, the throttle opening is defined as 100%, 70%, 30% and 0% as the dividing points, and the motor speed is 500 rpm, 2000 rpm, 3000 rpm and 4000 rpm as the dividing points. The demarcation point of the point and the motor speed combine to four such downshift critical points, namely (500rpm, 0%), (500rpm, 30%), (3000rpm, 70%) and (3000rpm, 100%), the normal upshift The threshold curve 42 also has four such upshift thresholds, namely (2000rpm, 0%), (2000rpm, 30%), (4000rpm, 70%) and (4000rpm, 100%). The two curves in FIG. 4 are only examples, the vehicle controller 30 can set and update the parameter values of the plurality of downshift thresholds and the plurality of upshift thresholds, for example, according to the model/performance of different electric scooters to formulate the Downshift threshold curve 41 and the normal upshift threshold curve 42 . Under the condition of the same throttle opening value, the motor speed corresponding to the normal upshift critical curve 42 is greater than the motor speed corresponding to the downshift critical curve 41, for example, the accelerator opening is 30%, the normal upshift The motor speed corresponding to the critical curve 42 is 2000 rpm, which is greater than the motor speed 500 rpm corresponding to the downshift critical curve 41 .

When the throttle opening of the electric locomotive and the actual rotational speed of the motor enter the right region of the normal upshifting critical curve 42, it means that the electric locomotive enters the second gear state; when the throttle opening of the electric locomotive and the motor When the actual speed value decreases to the left region of the downshift critical curve 41 , it represents that the electric locomotive enters the first gear state. The area between the normal upshifting critical curve 42 and the downshifting critical curve 41 is a buffer zone A. When the value of the accelerator opening of the electric locomotive and the actual speed of the motor enter the buffer zone A, the The electric scooter remains in its original gear state.

Therefore, in the above-mentioned step S203, if the electric vehicle information obtained by the vehicle controller 30 indicates that the current accelerator opening is 80%, and the actual speed of the motor is 4050 rpm (ie, the second state S ₂ ), and with the use of The operator operates the electric locomotive so that the accelerator opening is reduced to 40% and the actual speed of the motor is reduced to 500 rpm (ie, the second state S ₂ is changed to the first state S ₁ ). When the opening degree is 40%, the corresponding motor speed demarcation point on the downshift critical curve 41 is 1125rpm, and it is judged that the actual motor speed of 500rpm is less than the motor speed demarcation point of 1125rpm (500rpm<1125rpm), that is, the downshift condition is met, so it is issued A shift command is sent to the shift motor 50 to control the electric scooter to shift from the second gear to the first gear. In another case, if the state of the electric locomotive is only transitioned from the second state S ₂ to the buffer zone A, for example, to the third state S ₃ (ie, 2500rpm, 60%), the vehicle controller 30 does not A shift command is output.

In the above-mentioned step S301, if the electric locomotive information obtained by the vehicle controller 30 indicates that the current values of the accelerator opening and the actual speed of the motor are 40% and 500 rpm respectively (ie, the first state S ₁ ), with the use of The operator operates the electric scooter to increase the accelerator opening and the actual speed of the motor to 80% and 4050 rpm respectively (ie, the first state S ₁ is changed to the second state S ₂ ). The vehicle controller 30 according to the current accelerator The opening degree is 80%, and the corresponding motor speed demarcation point on the normal upshift critical curve 42 is 4000rpm, and it is judged that the actual motor speed of 4050rpm is greater than the motor speed demarcation point of 4000rpm (4050rpm>4000rpm), which meets the upshift condition, Therefore, a shift command is issued to the shift motor 50 to control the electric scooter to shift from the first gear to the second gear.

Referring to FIG. 5 , in the second embodiment of the gear shifting method of the present invention, the aforementioned steps S101 to S104 and the downshift determination process 200 are the same as the first embodiment of FIG. 2 , the difference lies in the In the second embodiment, the upshift conversion process 300 includes the following steps:

S301a: judging that the state of the acceleration correction flag is the first state or the second state;

S302a: when the state of the acceleration correction flag is the first state (for example, set to "1"), the vehicle controller 30 selects a correction upshift threshold curve 43 as the judgment criterion;

S303a: when the state of the acceleration correction flag is the first state (for example, cleared to "0"), the vehicle controller 30 selects the normal upshifting critical curve 42 as the judgment criterion;

S304a: The vehicle controller 30 compares the selected modified upshift critical curve 43 or the selected normal upshift critical curve 42 according to the accelerator opening of the electric locomotive and the actual rotational speed of the motor, and determines whether it conforms to the file condition;

S305a: If it is determined that the upshift condition is met, the vehicle controller 30 outputs a shift command to the shift motor 50 to shift the gear position from the first gear to the second gear.

Please refer to FIG. 6 , the corrected upshift critical curve 43 described in the above step S303 is different from the normal upshift critical curve 42 , and the four corrected upshift critical points of the corrected upshift critical curve 43 are respectively (3000rpm, 0 %), (3000rpm, 30%), (5000rpm, 70%) and (5000rpm, 100%), under the condition that the accelerator opening value is the same, the motor speed corresponding to the corrected upshift critical curve 43 is greater than the The normal upshift critical curve 42 corresponds to the motor speed, so the corrected upshift critical curve 43 and the normal upshift critical curve 42 do not overlap at all; however, in other embodiments, the corrected upshift critical curve 43 may be the same as the The normal upshift threshold curve 42 partially overlaps. When the vehicle controller 30 determines that the correction upshift critical curve 43 is selected as the determination criterion, it means that the electric locomotive has previously been rapidly downgraded from the second gear to the first gear because the acceleration correction condition is met. It lasts for a long time to avoid the gear shifting from the first gear to the second gear quickly again. Therefore, the corrected upshifting critical curve 43 is used as the judgment criterion, and the motor speed is required to be increased to a higher speed before changing to the second gear. Riders can enjoy better acceleration feeling in first gear.

In general, the gear shifting system and method of the present invention can provide the following gear shifting operations for electric locomotives:

1. Acceleration correction and downshift: when the electric scooter is in the second gear, when the rider urgently presses the accelerator handle and meets the acceleration correction conditions, the vehicle controller 30 issues a shift command to make the electric scooter switch from the second gear to the first gear. gear, so that the electric locomotive has higher acceleration performance.

2. Normal upshift/downshift: In the state where the electric scooter does not meet the acceleration correction conditions, the actual motor speed of the electric scooter can still be compared with the downshift critical curve 41 and the normal upshift critical curve 42. If In accordance with upshift/downshift conditions, control the electric scooter to shift to second or first gear.

3. Compensation upshift: When the electric locomotive is rapidly downgraded from the second gear to the first gear because it meets the acceleration compensation conditions, the vehicle controller 30 can refer to the preset correction and upshift critical curve 43 as a judgment basis to make the electric locomotive Upshifting conditions are met only when the motor speed is increased to a higher speed, which prevents a rapid shift from first to second gear.

To sum up, the present invention merely describes the implementation manner or example of the technical means adopted by the present invention to solve the problem, and is not intended to limit the scope of the patent implementation of the present invention. That is, all the equivalent changes and modifications that are consistent with the context of the scope of the patent application of the present invention, or made in accordance with the scope of the patent of the present invention, are all covered by the scope of the patent of the present invention.

10: Throttle valve position sensor 20: Motor controller 30: Vehicle controller 41: Downshift critical curve 42: Normal upshift critical curve 43: Corrected upshift critical curve 50: Shift motor 60: Gearbox 61: Actuating lever 62: Clutch 63: Gear set 70: Throttle handle 80: Motor 81: Hall sensor 100: Battery management system 200: Downshift judgment process 300: Upshift judgment process A: Buffer T: Throttle opening signal M : Motor speed signal S ₁ : First state S ₂ : Second state S ₃ : Third state

Fig. 1: The system block diagram of the gear shifting system of the electric locomotive of the present invention. Fig. 2 is a flow chart of the first embodiment of the gear shifting method of the electric locomotive of the present invention. FIG. 3 is a sampling diagram of the average throttle change rate in the present invention. FIG. 4 is a schematic diagram of a downshift boundary curve and a normal upshift boundary curve in the present invention. Fig. 5 is a flow chart of the second embodiment of the gear shifting method of the electric locomotive of the present invention. FIG. 6 is a schematic diagram of a downshift boundary curve and an acceleration upshift boundary curve in the present invention.

10: Throttle position sensor 20: Motor Controller 30: Vehicle Controller 50: Shift motor 60: Gearbox 61: Actuator 62: Clutch 63: Gear Set 70: Throttle handle 80: Motor 81: Hall sensor 100: Battery Management System T: accelerator opening signal M: Motor speed signal

Claims (12)

A gear shifting system of an electric locomotive, the electric locomotive comprises a motor, a shifting motor and a gearbox, the electric locomotive can alternately switch gears between the first gear and the second gear, the gear shifting system of the electric locomotive Include: The throttle valve position sensor senses a throttle opening to generate a throttle opening signal; a motor controller, receiving a motor speed signal, the motor speed signal representing an actual speed of a motor of the motor; a vehicle controller, electrically connected to the throttle position sensor and the motor controller, for receiving the accelerator opening signal and the motor speed signal, the vehicle controller calculates an average value according to the accelerator opening signal Throttle change rate; Wherein, the vehicle controller is preset with an acceleration correction condition, and the acceleration correction condition includes judging whether the average throttle change rate is greater than or equal to a preset threshold value, when the electric locomotive is in the second gear, if the vehicle controller It is judged that the average throttle change rate is greater than or equal to the preset threshold value, and a shift command is output to the shift motor to control the gear of the electric scooter to switch to the first gear. The gear shifting system for an electric scooter according to claim 1, wherein the acceleration correction condition further comprises: judging whether the battery temperature is lower than a temperature threshold, whether the battery residual power is greater than or equal to a power threshold, and the actual speed of the motor Whether it is less than or equal to a speed threshold; When the vehicle controller determines that all the acceleration correction conditions are satisfied, it outputs the shift command to the shift motor to control the gear position of the electric scooter to switch to the first gear. The gear shifting system for an electric locomotive as claimed in claim 1, wherein the vehicle controller presets a downshift critical curve and a normal upshift critical curve, and the downshift critical curve includes a range determined by the motor speed and the accelerator opening. The defined complex downshift critical point, the normal upshift critical curve includes the complex upshift critical point defined by the motor speed and the throttle opening, under the condition that the accelerator opening value is the same, the normal upshift critical curve corresponds to The motor speed is greater than the motor speed corresponding to the downshift critical curve; Wherein, when the electric scooter is in the second gear, the vehicle controller compares with the downshift threshold curve according to the accelerator opening signal and the motor speed signal to determine whether to output a shift command to control the electric scooter to downshift. files; When the electric scooter is in the first gear, the vehicle controller compares with the downshift threshold curve according to the accelerator opening signal and the motor speed signal to determine whether to output a shift command to control the electric scooter to upshift. The gear shifting system of the electric locomotive as claimed in claim 3, wherein when the electric locomotive is in the second gear, the vehicle controller uses the current accelerator opening of the electric locomotive as a reference, on the downshifting critical curve The motor speed corresponding to the throttle opening is compared with the current actual speed of the motor. If the actual speed of the motor is less than the motor speed corresponding to the downshift critical curve, the vehicle controller outputs the shift command to control the motor car downshift; When the electric locomotive is in the first gear, the vehicle controller uses the current accelerator opening of the electric locomotive as a reference, and compares the motor speed corresponding to the accelerator opening on the upshift critical curve with the current actual speed of the motor , if the actual rotational speed of the motor is greater than the rotational speed of the motor corresponding to the upshift critical curve, the vehicle controller outputs the shift command to control the electric scooter to upshift. The gear shifting system of an electric locomotive as claimed in claim 1 or 2, wherein the vehicle controller presets a revising upshift threshold curve, and the revising upshift threshold curve includes a complex number defined by the motor speed and the accelerator opening degree Upshift critical point; Wherein, after the electric scooter is switched to the first gear due to the acceleration correction condition, the vehicle controller compares the threshold curve with the correction upshift threshold according to the accelerator opening signal and the motor speed signal to determine whether to output A shift command is used to control the shift motor to switch the gear position of the electric scooter to the second gear. According to the gear shifting system of the electric locomotive as claimed in claim 1, the shifting motor controls the gearbox to shift gears according to the shifting command, wherein the gearbox includes at least one clutch and at least one gear set. According to the gear shifting system of the electric scooter according to claim 1, the motor is provided with a Hall sensor, and the Hall sensor senses the actual speed of the motor to output a signal of the motor speed. A gear shifting method of an electric locomotive, the electric locomotive includes a motor and can alternately switch gears between the first gear and the second gear, and the automatic shifting method of the electric locomotive comprises: Sensing a throttle opening and a motor actual speed of the electric locomotive to generate a throttle opening signal and a motor speed signal respectively; Calculate an average throttle change rate according to the throttle opening; Presetting an acceleration correction condition, wherein the acceleration correction condition includes determining whether the average throttle change rate is greater than or equal to a predetermined threshold value; When the electric scooter is in the second gear, determine whether the average throttle change rate is greater than or equal to the preset threshold value, and if so, output a shift command to control the electric scooter to switch the gear to the first gear. According to the gear shifting method for an electric scooter according to claim 8, the acceleration correction condition further comprises: judging whether the battery temperature is lower than a temperature threshold, whether the battery residual power is greater than or equal to a power threshold, and whether the actual speed of the motor is less than or equal to a speed threshold; When it is determined that all the acceleration correction conditions are established, the shift command is output to control the gear position of the electric scooter to switch to the first gear. The gear shifting method for an electric locomotive according to claim 8, further comprising: A downshift critical curve and a normal upshift critical curve are preset, wherein the downshift critical curve includes a downshift critical point defined by the motor speed and the accelerator opening, and the normal upshift critical curve includes a motor The upshift critical point defined by the rotational speed and the accelerator opening, under the same accelerator opening, the motor speed on the normal upshift critical curve is greater than the motor speed on the downshift critical curve; Wherein, when the electric scooter is in the second gear, according to the accelerator opening signal and the motor speed signal, and the downshift critical curve is compared with each other to determine whether to output a shift command to control the electric scooter to downshift; When the electric scooter is in the first gear, according to the accelerator opening signal and the motor speed signal, the downshift threshold curve is compared with each other to determine whether to output a shift command to control the electric scooter to shift up. The gear shifting method for an electric locomotive as claimed in claim 10, wherein: When the electric locomotive is in the second gear, the current throttle opening of the electric locomotive is used as a benchmark, and the motor speed corresponding to the throttle opening on the downshift critical curve is compared with the current actual speed of the motor. The rotational speed is lower than the rotational speed of the motor corresponding to the downshifting critical curve, and the shifting command is output to control downshifting of the electric locomotive; When the electric locomotive is in the first gear, the current throttle opening of the electric locomotive is used as a benchmark, and the motor speed corresponding to the throttle opening on the upshift critical curve is compared with the current actual speed of the motor. When the rotational speed is greater than the corresponding motor rotational speed on the upshift critical curve, the shift command is output to control the electric locomotive to upshift. The gear shifting method for an electric locomotive according to claim 8 or 9, further comprising: Presetting a modified upshift critical curve, the modified upshift critical curve includes a plurality of upshift critical points defined by the motor speed and the accelerator opening; Wherein, after the electric scooter is switched to the first gear due to meeting the acceleration correction condition, according to the accelerator opening signal and the motor speed signal, it is compared with the corrected upshift threshold curve to determine whether to output a shift command to Controls the upshift of an electric locomotive.

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