Motor shifting smoothness control method and system

Abstract

The embodiment of the present invention relates to the field of motor technology, and discloses a control method and system for the smoothness of motor gear shifting, the method comprising: collecting the initial pedaling torque value and wheel speed, predicting the gear shifting moment according to the initial pedaling torque value and wheel speed; calculating the gear shifting pedaling torque value after the gear shifting according to the predicted gear shifting moment, and fitting a torque smooth change curve related to time according to the initial pedaling torque value and the gear shifting pedaling torque value, and obtaining the target pedaling torque value at the current moment; adjusting the power assist ratio of the motor according to the target pedaling torque value so that the pedaling torque value is equal to the target pedaling torque value; adjusting the power assist ratio of the motor within the first preset time before the predicted gear shifting moment so that the pedaling torque value within the first preset time is equal to the first preset pedaling torque value until the gear shifting is completed. The application of the technical solution of the present invention can solve the problem of obviously feeling the increase or decrease of riding resistance during sudden gear shifting, thereby affecting the riding experience.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of motors, and in particular to a method and system for controlling the smoothness of motor gear shifting. Background Art

[0002] Electric power-assisted bicycles can effectively save the rider's physical energy and also have the effect of exercise and fitness. They are currently favored by more and more riders.

[0003] Due to the effect of electric power, the force required to pedal will change during riding. Usually, as the power ratio increases or the speed increases, the rider will often feel like they are stepping on empty pedals. At this time, the only way to restore the normal riding feeling is to slow down or increase the pedaling frequency.

[0004] In order to avoid this situation, the prior art has adopted a motor internal speed change mechanism to improve the riding experience, specifically using centrifugal force to achieve automatic speed change, including a clutch inner ring, a drive ring plate sleeved on the clutch inner ring, a fixed plate integrally formed on the outer wall of the clutch inner ring, a centrifugal block used to drive the drive ring plate to rotate is provided on the fixed plate; an axial limit structure is provided between the drive ring plate and the clutch inner ring, the axial limit structure includes a limit plate integrally formed on the drive ring plate, and a limit groove matched with the limit plate; the limit groove includes an axial opening matched with the limit plate. When this speed change mechanism reaches a certain speed, the centrifugal block is thrown away to achieve automatic upshifting, and when the speed drops below the speed change point, the centrifugal block will shrink to achieve automatic downshifting, thereby achieving a riding feeling of having a certain resistance at a low pedaling frequency when riding at high speed.

[0005] However, since the above-mentioned speed change adopts a purely mechanical structure, there is often a sudden increase in torque, which causes the rider to clearly feel the increase or decrease in riding resistance at the moment of gear shifting, thus affecting the riding experience. In related technologies, the control method is mostly passive response, that is, after the torque change is detected after the gear shift, compensation adjustment is made. This method cannot effectively avoid the abrupt feeling at the moment of gear shifting. Summary of the invention

[0006] In view of the above problems, an embodiment of the present invention provides a method for controlling the smoothness of motor gear shifting, which is used to solve the problem that the riding resistance is obviously increased or decreased during sudden gear shifting, thereby affecting the riding experience.

[0007] According to a first aspect of the present invention, a method for controlling motor shifting smoothness is provided, the method comprising:

[0008] Collecting initial pedal torque value and wheel speed, and predicting shifting time according to the initial pedal torque value and wheel speed;

[0009] According to the predicted shifting moment, the shifting pedal torque value after the shifting is calculated, and the time-related torque smooth change curve is fitted according to the initial pedal torque value and the shifting pedal torque value, and the target pedal torque value at the current moment is obtained;

[0010] adjusting the assist ratio of the motor according to the target pedaling torque value so that the pedaling torque value is equal to the target pedaling torque value;

[0011] Adjusting the power assist ratio of the motor within a first preset time before the predicted gear shifting moment so that the pedal force torque value within the first preset time is equal to the first preset pedal force torque value until the gear shifting is completed;

[0012] Wherein, the initial pedaling torque value and the target pedaling torque value are both greater than the first preset pedaling torque value.

[0013] In an optional manner, predicting the shifting time according to the initial pedal torque value and the wheel speed comprises the following sub-steps:

[0014] Construct a neural network model with multi-layer perception mechanism;

[0015] Obtaining the power assist ratio of the motor, and using the power assist ratio, initial pedal torque value and wheel speed as input parameters for prediction;

[0016] Among them, the neural network model uses the Relu function as the activation function, Adam as the optimizer, and the mean square error function as the loss function.

[0017] In an optional manner, the input parameter further includes a riding intention prediction parameter, and the riding intention prediction parameter is obtained by the following steps:

[0018] Based on pedal torque value and wheel speed;

[0019] When the pedal force torque value is greater than the first preset torque, and the wheel speed is less than the first preset wheel speed, the riding intention prediction parameter is acceleration intention;

[0020] When the pedaling torque value is equal to the first preset torque, or when the pedaling torque value is greater than the first preset torque and the wheel speed is greater than or equal to the first preset wheel speed, the riding intention prediction parameter is a uniform speed intention;

[0021] When the pedaling torque value is less than the first preset torque, the riding intention prediction parameter is a deceleration intention.

[0022] In an optional manner, the calculating the shift pedal torque value after the gear shift according to the predicted gear shift moment includes:

[0023] Obtain the shift torque difference of the motor;

[0024] The initial pedal torque value and the shift torque difference value are summed to obtain the shift pedal torque value after the gear shift.

[0025] In another optional manner, the step of calculating the shift pedal torque value after the gear shift according to the predicted gear shift moment may further include:

[0026] Obtain the shift torque difference of the motor;

[0027] The initial pedal torque value and the shift torque difference value are summed, and when the sum result is greater than a first threshold value, the shift torque difference is corrected, and the sum of the corrected shift torque difference value and the initial pedal torque value is used as the shift pedal torque value after the gear shift.

[0028] In an optional manner, after the gear shift is completed, the following steps are also included:

[0029] Setting a second preset time;

[0030] The motor assist ratio is gradually adjusted within the second preset time so that the pedaling torque value approaches the initial pedaling torque value.

[0031] In an optional manner, fitting a time-dependent torque smooth change curve according to the initial pedal torque value and the gear shift pedal torque value includes:

[0032] The duration from the current moment to the moment of the first preset time before the predicted gear shifting moment;

[0033] The value of the initial pedal torque value and the value of the gear-shift pedal torque value are taken as two extreme values ​​of the function;

[0034] A smooth transition function is constructed with time as the horizontal coordinate and the pedal torque value as the vertical coordinate, in which the torque value corresponding to each moment is the target torque value at that moment.

[0035] In an optional manner, the smooth transition function includes:

[0036] Acceleration shifting: ;

[0037] Slow down and shift gears: ;

[0038] in, is the initial pedal torque value; Shift pedal torque value; k is the compensation constant, and t is the current moment.

[0039] In an optional manner, the step of adjusting the assist ratio of the motor within a first preset time before the predicted gear shifting moment so that the pedaling torque value within the first preset time is equal to the first preset pedaling torque value until the gear shifting is completed comprises the following sub-steps:

[0040] Get the current time and calculate the duration from the current time to the gear shifting time;

[0041] When the time duration is less than or equal to the first preset time, the target pedaling torque is set to a first preset pedaling torque value;

[0042] The assist ratio of the motor is adjusted so that the pedal force torque value at the current moment tends to the first preset pedal force torque value until the gear shift is completed.

[0043] According to a second aspect of the present invention, a control system for motor shifting smoothness is provided, the system comprising:

[0044] The acquisition module is used to detect and obtain the rider's initial pedal torque value and wheel speed in real time;

[0045] a processing module, configured to receive the data transmitted by the acquisition module, predict the gear shifting moment according to the initial pedaling torque value and the wheel speed, calculate the gear shifting pedaling torque value after the gear shifting, and fit a torque smoothing change curve related to time according to the initial pedaling torque value and the gear shifting pedaling torque value, and obtain a target pedaling torque value at a current moment, and adjust the target pedaling torque value to a first preset pedaling torque value within a first preset time before the predicted gear shifting moment, until the gear shifting is completed; and

[0046] The driving module is used to receive the target pedal torque value sent by the processing module, and adjust the power assistance ratio of the motor according to the target pedal torque value so that the pedal torque value is equal to the target pedal torque value.

[0047] According to a third aspect of the present invention, there is provided a control device for smoothness of motor gear shifting, the device comprising:

[0048] A processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus;

[0049] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute the operation of the motor shifting smoothness control method.

[0050] The beneficial effects of the present invention are:

[0051] The control method of the smoothness of motor shifting of the present invention predicts the shifting time according to the initial pedaling torque value and the wheel speed, calculates the shifting pedaling torque value after the shifting, fits the torque smooth change curve related to time, and obtains the target pedaling torque value at the current moment, and adjusts the power assist ratio of the motor according to the target pedaling torque value so that the pedaling torque value is equal to the target pedaling torque value, and adjusts the power assist ratio of the motor before predicting the shifting time so that the pedaling torque value is equal to the initial pedaling torque value. In this way, the pedaling torque value before the motor shifts is equal to the target pedaling torque value, and there is only a short sense of pedaling power loss during the shifting, avoiding the obvious increase or decrease of riding resistance during sudden shifting, further ensuring the smoothness of the motor shifting, and at the same time reminding the rider that the gear has been shifted, thereby improving the riding experience.

[0052] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0054] Figure 1 A schematic flow chart showing a first embodiment of a method for controlling motor shifting smoothness provided by the present invention;

[0055] Figure 2 A schematic flow chart showing the sub-steps of step 110 of the first embodiment of the method for controlling the smoothness of motor gear shifting provided by the present invention;

[0056] Figure 3 A schematic flow chart showing the sub-steps of step 112 of the first embodiment of the method for controlling the smoothness of motor gear shifting provided by the present invention;

[0057] Figure 4 A schematic flow chart showing the sub-steps of step 120 of the first embodiment of the method for controlling the smoothness of motor gear shifting provided by the present invention;

[0058] Figure 5 A schematic flow chart showing the steps after step 140 of the first embodiment of the method for controlling the smoothness of motor gear shifting provided by the present invention;

[0059] Figure 6 A schematic diagram showing the structure of a control system for smooth motor gear shifting provided by the present invention;

[0060] Figure 7A schematic diagram of the structure of a control device for smooth motor gear shifting provided by the present invention is shown. DETAILED DESCRIPTION

[0061] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0062] Embodiment 1:

[0063] Figure 1 The flow chart of a method for controlling the smoothness of motor gear shifting according to the present invention is shown, and the method is executed based on the acquisition module. Figure 1 As shown, the method comprises the following steps:

[0064] S110, collecting initial pedal torque value and wheel speed, and predicting the gear shifting time according to the initial pedal torque value and wheel speed.

[0065] Among them, the rider's initial pedal torque value is collected by the torque sensor, and the speed sensor collects the wheel's travel speed. According to the initial pedal torque value and the wheel's travel speed, the rider's shifting moment is predicted, that is, the timing when the rider wants to speed up and / or slow down the riding speed is predicted, that is, the motor's shifting timing. It should be noted that the pedal torque value refers to the parameter formed by the force applied by the rider on the pedal to rotate the minimum motion unit of the pedal obtained by the torque sensor. When the rider steps on the pedal, the torque analysis system converts these actions into specific torque values, that is, the pedal torque value. Further, in the field of power-assisted bicycles, due to the effect of the power-assisted motor, the rider's pedal torque value will change according to the output power of the power-assisted motor. For example, when the output power of the power-assisted motor is large, in this riding state, the rider uses less force, so the pedal torque value is small; when the output power of the power-assisted motor is small, in this riding state, the pedal torque value is larger.

[0066] S120, calculating the gear shift pedal torque value after the gear shift according to the predicted gear shifting moment, fitting a time-related torque smoothing curve according to the initial pedal torque value and the gear shift pedal torque value, and obtaining the target pedal torque value at the current moment.

[0067] Among them, according to the predicted gear shifting moment, the pedal torque value expected to be achieved after the gear shifting is calculated, and the torque smooth change curve is fitted according to the initial pedal torque value and the predicted gear shifting pedal torque value, and the target pedal torque value of the rider at the current moment is obtained according to the torque smooth change curve. It should be noted that the torque smooth change curve refers to the target pedal torque value that the rider needs to apply to the pedals at each moment when maintaining the current riding state.

[0068] S130, adjusting the assist ratio of the motor according to the target pedaling torque value so that the pedaling torque value is equal to the target pedaling torque value.

[0069] Among them, the power assist ratio of the motor is adjusted according to the target pedal torque value. The motor power assist output required to achieve the target pedal torque value under acceleration and / or deceleration can be quickly obtained by looking up a table, etc., thereby forming a power assist ratio; the power assist ratio of the motor is adjusted to make the pedal torque value equal to the target pedal torque value, that is, as time changes, the pedal torque value gradually tends to and equals the target torque value, so that the power-assisted bicycle can be maintained in a certain riding state, and the rider's pedal torque can change according to the target pedal torque. A smoother torque change is achieved when shifting gears, avoiding sudden changes in resistance caused by sudden shifting gears, thereby ensuring the riding smoothness of the rider when shifting gears.

[0070] S140. Adjust the power assistance ratio of the motor within a first preset time before the predicted gear shifting moment, so that the pedaling torque value within the first preset time is equal to the first preset pedaling torque value, until the gear shifting is completed.

[0071] Among them, the first preset time is any value between 0.2s and 0.5s, and the power assistance ratio of the motor is adjusted during this period so that the pedal torque value within the first preset time is equal to the first preset pedal torque value until the gear shift is completed.

[0072] In addition, it should be noted that the initial pedaling torque value and the target pedaling torque value are both greater than the first preset pedaling torque value, so that the pedaling torque becomes smaller in the short time before the gear shift, so as to reduce the discomfort of the rider.

[0073] At this time, the rider only feels a very brief feeling of stepping on the pedals, and the pedal force quickly returns to the original value after the gear shift is completed. In this process, the force used by the rider is relatively avoided. The pedal torque value suddenly changes and cannot be quickly restored due to the motor shift, and the rider feels a strong sense of stepping on the pedals for a long time or suddenly feels a strong riding resistance, thereby ensuring the riding smoothness when the motor shifts; at the same time, the gear shifting method in this embodiment also serves to remind the rider that the motor has shifted gears.

[0074] Please combine Figure 2 , Figure 2 A flow chart of the sub-steps in step 110 of the method for controlling the smoothness of motor gear shifting provided by the present invention is shown.

[0075] In step S110, predicting the shifting time according to the initial pedal torque value and the wheel speed includes the following sub-steps:

[0076] S111. Construct a neural network model with multi-layer perception mechanism;

[0077] S112, obtaining the power assist ratio of the motor, and using the power assist ratio, the initial pedal torque value and the wheel speed as input parameters for prediction;

[0078] The neural network model uses Relu function (Linear rectification function) as the activation function, Adam as the optimizer, and mean square error function as the loss function.

[0079] In some embodiments, the power assist ratio of the motor is obtained according to the initial pedaling torque value, and the power assist ratio, the initial pedaling torque value and the driving speed of the wheel are used as input parameters, and a neural network model is used for prediction to predict the gear shifting timing of the rider.

[0080] It should be noted that the Relu function is a ramp function. In a neural network, the Relu function serves as the activation function of a neuron and defines the nonlinear output of the neuron after linear transformation.

[0081] Please combine Figure 3 , Figure 3 A flow chart of the sub-steps in step 112 of the method for controlling the smoothness of motor gear shifting provided by the present invention is shown.

[0082] In step S112, the input parameters also include a riding intention prediction parameter, and the riding intention prediction parameter is obtained by the following steps:

[0083] S1121, based on the pedal torque value and the wheel speed.

[0084] S1122: when the pedal force torque value is greater than the first preset force torque and the wheel speed is less than the first preset wheel speed, the riding intention prediction parameter is acceleration intention;

[0085] S1123: when the pedaling torque value is equal to the first preset torque, or when the pedaling torque value is greater than the first preset torque and the wheel speed is greater than or equal to the first preset wheel speed, the riding intention prediction parameter is a uniform speed intention;

[0086] S1124: When the pedaling torque value is less than the first preset torque, the riding intention prediction parameter is a deceleration intention.

[0087] In some embodiments, based on the collected pedal torque value and wheel speed, by comparing the pedal torque value and the first preset torque, and comparing the wheel speed and the first preset wheel speed, when the pedal torque value is greater than the first preset torque, and the wheel speed is less than the first preset wheel speed, the riding intention prediction parameter is the acceleration intention; it can be understood that when accelerating uphill or decelerating downhill, the wheel speed of the power-assisted bicycle will slow down due to uphill resistance or downhill braking, and when acceleration is required, the pedal torque value will be greater than the pedal torque value in the normal riding state, thereby judging the rider's acceleration intention. The gear shifting moment is predicted according to the acceleration intention, and the motor power output is adjusted in advance to ensure the riding smoothness when the motor shifts gears, and at the same time make the rider more labor-saving when riding on special sections, such as uphill.

[0088] Furthermore, when the pedal force torque value is equal to the first preset torque, or the pedal force torque value is greater than the first preset torque and the wheel speed is equal to the first preset wheel speed, the rider's uniform speed intention is determined. At this time, the power output of the motor is not adjusted, thereby ensuring the stability of the rider's uniform speed riding.

[0089] Furthermore, when the pedal force torque value is less than the first preset torque, the rider's deceleration intention can be determined. The gear shifting time is predicted according to the deceleration intention, and the motor power output is adjusted in advance to ensure the smoothness of the motor gear shifting, while making the rider ride more smoothly on special roads, such as downhill, and improving riding safety.

[0090] It should be noted that the first preset torque is the cruising torque, that is, the pedal torque value of the power-assisted bicycle under normal riding conditions. The torque can be any value between 0.1Nm and 15Nm, and the value will be adjusted according to the weight of the rider and the change of riding strategy. In some embodiments, the value can be a value set by the user, and can be obtained after adjustment after a certain period of machine learning based on the neural network model, so that the cruising torque can be personalized with the user. In addition, the first preset wheel speed is the maximum speed of riding, and the speed can be between 25km / h and 35km / h. In some embodiments, the first preset wheel speed can be set to be adjustable, which can be specifically matched according to different riders. For example, for the elderly, children, etc., the first preset wheel speed can be appropriately reduced to ensure riding safety.

[0091] Please combine Figure 4 , Figure 4 A flowchart of the sub-steps in step 120 of a method for controlling motor gear shifting smoothness in one embodiment of the present invention is shown.

[0092] In step S120, according to the predicted shifting time, calculating the shifting pedal torque value after the shifting includes the following sub-steps:

[0093] S121. Obtain the shift torque difference of the motor.

[0094] Among them, according to the difference in motor models and parameters, the torque difference before and after the gear shift of different motors is different, but for the same motor, the torque before and after the gear shift is the same. Therefore, the gear shift torque difference of the motor can be given by the manufacturer, or calculated before and after the motor shifts multiple times. In a better case, a more accurate and real-time gear shift torque difference can be obtained by the system's own calculation before and after the motor shifts.

[0095] For example, a scene dedicated to identifying the shift torque difference can be configured to make the power-assisted bicycle complete a gear shift under the premise of uniform acceleration and identify the gear shift node. The system obtains the current pedal torque and the pedal torque after the gear shift through the sensor. The difference between the two pedal torques can be calculated to calculate the shift torque difference. At the same time, different accelerations can be set and multiple measurements can be made to obtain a more accurate shift torque difference.

[0096] S122: sum the initial pedal torque value and the shift torque difference value to obtain the shift pedal torque value after the gear shift.

[0097] In the calculation process, the initial pedal torque value and the shift torque difference value are summed to obtain the shift pedal torque value after the gear shift. In the acceleration scenario, the shift torque difference is a positive value, and in the deceleration scenario, the shift torque difference is a negative value. Finally, the shift pedal torque value after the gear shift can be obtained by summing them.

[0098] The shift pedal torque value calculated by the above method will be very close to the actual pedal torque value after the shift, so that the constructed torque smooth change curve is more accurate.

[0099] In addition, in another embodiment of the present invention, in order to avoid the pedal torque being too large or too small, according to the predicted shifting time, calculating the shifting pedal torque value after the shifting may further include the following steps:

[0100] S121', obtaining the shift torque difference of the motor. This step is similar to step S121, so it will not be repeated here.

[0101] S122', summing the initial pedal torque value and the shift torque difference value, and when the sum result is greater than the first threshold, correcting the shift torque difference, and taking the sum of the corrected shift torque difference value and the initial pedal torque value as the shift pedal torque value after the gear shift.

[0102] Specifically, the first threshold value is used to define whether the pedal torque value is too large. When the pedal torque value is too large, it will make it difficult for the user to continue riding. The value after the sum of the initial pedal torque value and the shift torque difference value is generally the shift pedal torque value after the gear shift. This value can improve the user's comfort within a certain reasonable range, but when the value is greater than the first threshold value, the shift torque difference will need to be corrected, so as to correct the shift pedal torque after the gear shift. The correction is usually to reduce the value of the shift torque difference so that the pedal torque value is always kept within the comfortable range of the other rider. It should be noted that the correction of the shift torque difference is not a correction of the shift torque difference in the physical sense, but is based on parameterizing the shift torque difference, and applying the parameter to control the shift pedal torque value after the gear shift. In addition, in terms of the motor, its specific control of the pedal torque can be reflected in the adjustment of the power ratio. That is, by adjusting the power ratio, the adjustment of the pedal torque can be achieved under the current riding state. Therefore, after obtaining the gear shift pedal torque in the above manner, the present invention can control the pedal torque value before and after the gear shift by increasing the motor output power to ensure the user's comfort. Preferably, the above first threshold value can be a value greater than 50Nm.

[0103] It is understandable that in more extreme scenarios, more active power output can be used to keep the pedal torque value curve before and after the gear shift as a gentle or even straight curve. For example, the calculated gear shift pedal torque value after the gear shift is compensated and corrected to make it close to the initial pedal torque value, and active power output is used to prevent the pedal torque curves before the gear shift and after the gear shift from fluctuating significantly.

[0104] Please combine Figure 5 , Figure 5 A flow chart showing the steps after step 140 of the method for controlling the smoothness of motor gear shifting provided by the present invention is shown.

[0105] In step S140, after the gear shift is completed, the following steps are also included:

[0106] S150, setting a second preset time;

[0107] S160, gradually adjusting the motor assist ratio within a second preset time so that the pedaling torque value approaches the initial pedaling torque value.

[0108] In some embodiments, the second preset time is any period between 3s and 5s, and the power assist ratio of the motor is gradually adjusted during this period so that the pedal torque value gradually approaches the initial pedal torque value within the second preset time. It can be understood that after the motor shifts gears, the power assist ratio of the motor is adjusted, so that the power assist output of the motor gradually decreases, thereby gradually reducing the wheel speed, and the power-assisted bicycle returns to the power assist output before the shift between 3s and 5s after the shift, so that the pedal torque value approaches the initial pedal torque value, thereby ensuring riding smoothness after the shift.

[0109] In some preferred embodiments, in order to better fit the torque smooth change curve, in step S120, a time-dependent torque smooth change curve is fitted according to the initial pedal torque value and the gear shift pedal torque value, including:

[0110] The duration from the current moment to the moment of the first preset time before the predicted gear shifting moment;

[0111] The value of the initial pedal torque value and the value of the gear-shift pedal torque value are taken as two extreme values ​​of the function;

[0112] A smooth transition function is constructed with time as the horizontal coordinate and the pedal torque value as the vertical coordinate, in which the torque value corresponding to each moment is the target torque value at that moment.

[0113] In some embodiments, a smooth transition function, i.e., a torque smooth change curve, is constructed by taking time as the horizontal coordinate and the pedal torque value as the vertical coordinate, and the pedal torque values ​​corresponding to before, during, and after the gear shift are predicted as the target torque value at that moment. By constructing a smooth transition function, the smoothness of the motor gear shift is ensured, and the riding experience of the rider is further improved.

[0114] Furthermore, the smooth transition function includes:

[0115] Acceleration shifting: ;

[0116] Slow down and shift gears: ;

[0117] in, is the initial pedal torque value; Shift pedal torque value; t is the current moment, k is the compensation constant, which is related to the total torque adjustment duration. The longer the torque adjustment time, the smaller the k value.

[0118] The construction of the above function can be that the torque change will have a relatively gentle slope in the initial and final stages of the torque adjustment period before the gear shift, and a relatively uniform change in the middle stage of the change, thereby ensuring the comfort and smoothness of the rider's riding.

[0119] In step S140, within a first preset time before the predicted gear shifting moment, the assist ratio of the motor is adjusted so that the pedaling torque value within the first preset time is equal to the first preset pedaling torque value until the gear shifting is completed; the step includes the following sub-steps:

[0120] Get the current time and calculate the duration from the current time to the gear shifting time;

[0121] When the time duration is less than or equal to the first preset time, the target pedaling torque is set to the first preset pedaling torque value;

[0122] The assist ratio of the motor is adjusted so that the pedal force torque value at the current moment tends to the first preset pedal force torque value until the gear shift is completed.

[0123] In some embodiments, by obtaining the current moment, the duration from the current moment to the gear shifting moment is calculated. When the duration is less than the first preset time, i.e., less than 0.5s, the target pedal torque is set to the first preset pedal torque value, and the power assist ratio of the motor is adjusted. By adjusting the power assist output of the motor, the wheel speed is accelerated or slowed down, and the pedal torque value at the current moment is made to approach the first preset pedal torque value. The stability of the power-assisted bicycle after gear shifting is ensured, and the reliability of the smooth gear shifting of the motor is further improved.

[0124] The above method predicts the gear shifting moment according to the initial pedaling torque value and the wheel speed, calculates the gear shifting pedaling torque value after the gear shifting, fits the torque smooth change curve related to time, and obtains the target pedaling torque value at the current moment, and adjusts the power assist ratio of the motor according to the target pedaling torque value so that the pedaling torque value is equal to the target pedaling torque value, and adjusts the power assist ratio of the motor before predicting the gear shifting moment so that the pedaling torque value is equal to the initial pedaling torque value. In this way, the pedaling torque value before the motor shifts gears is equal to the target pedaling torque value, and there is only a short sense of pedaling power loss when shifting gears, avoiding the obvious increase or decrease in riding resistance when shifting gears suddenly, further ensuring the smoothness of the motor shifting, and at the same time reminding the rider that the gear has been shifted, thereby improving the riding experience.

[0125] Embodiment 2:

[0126] Figure 6 FIG. 2 is a schematic diagram showing a structure of an embodiment of a control system for smooth motor shifting according to the present invention. Figure 6 As shown, the system 60 includes: a collection module 61, a processing module 62 and a driving module 63.

[0127] The acquisition module 61 is used to detect and obtain the rider's initial pedal torque value and wheel speed in real time;

[0128] The processing module 62 is used to receive the data transmitted by the acquisition module 61, predict the gear shifting moment according to the initial pedaling torque value and the wheel speed, calculate the gear shifting pedaling torque value after the gear shifting, and fit the time-related torque smooth change curve according to the initial pedaling torque value and the gear shifting pedaling torque value, and obtain the target pedaling torque value at the current moment, and adjust the target pedaling torque value to the first preset pedaling torque value within a first preset time before the predicted gear shifting moment, until the gear shifting is completed;

[0129] The driving module 63 is used to receive the target pedaling torque value sent by the processing module 62, and adjust the assist ratio of the motor according to the target pedaling torque value so that the pedaling torque value is equal to the target pedaling torque value.

[0130] The above system realizes the control method of smooth motor gear shifting, which can solve the problem of obviously feeling the increase or decrease of riding resistance during sudden gear shifting, thereby affecting the riding experience.

[0131] Embodiment 3:

[0132] Figure 7 FIG. 1 shows a schematic diagram of the structure of an embodiment of an electronic device of the present invention. Figure 7 As shown, the electronic device is specifically a control device for motor gear shifting smoothness, and may include: a processor (processor) 701, a communication interface (Communications Interface) 702, a memory (memory) 703, and a communication bus 704.

[0133] The processor 701, the communication interface 702, and the memory 703 communicate with each other through the communication bus 704. The communication interface 702 is used to communicate with other devices such as a client or other server network elements. The processor 701 is used to execute the program 710, which can specifically execute the relevant steps in the above-mentioned motor shifting smoothness control method embodiment.

[0134] Specifically, the program 710 may include program code including computer executable instructions.

[0135] The processor 701 may be a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiment of the present invention. The one or more processors included in the motor shifting smoothness control device may be processors of the same type, such as one or more CPUs; or may be processors of different types, such as one or more CPUs and one or more ASICs.

[0136] The memory 703 is used to store the program 710. The memory 703 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0137] Program 710 can be specifically called by processor 701 to enable the control device for smooth motor shifting to perform the following operations:

[0138] Collecting initial pedal torque value and wheel speed, and predicting shifting time according to the initial pedal torque value and wheel speed;

[0139] According to the predicted shifting moment, the shifting pedal torque value after the shifting is calculated, and the time-related torque smooth change curve is fitted according to the initial pedal torque value and the shifting pedal torque value, and the target pedal torque value at the current moment is obtained;

[0140] The assist ratio of the motor is adjusted according to the target pedal torque value so that the pedal torque value is equal to the target pedal torque value;

[0141] Within a first preset time before the predicted gear shifting moment, the assist ratio of the motor is adjusted so that the pedal force torque value within the first preset time is equal to the first preset pedal force torque value until the gear shifting is completed.

[0142] Furthermore, the program 710 can also be called by the processor 701 to enable the control device for smooth motor gear shifting to perform other operations in Embodiment 1 of the present invention, which will not be described in detail.

[0143] The control method for achieving smooth motor gear shifting by the above devices can solve the problem of obviously feeling an increase or decrease in riding resistance during sudden gear shifting, which in turn affects the riding experience.

[0144] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system or other device. In addition, the embodiments of the present invention are not directed to any particular programming language.

[0145] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0146] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0147] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A method for controlling the smoothness of motor gear shifting, characterized in that: The steps include: Collecting initial pedal torque value and wheel speed, and predicting shifting time according to the initial pedal torque value and wheel speed; According to the predicted shifting moment, the shifting pedal torque value after the shifting is calculated, and the time-related torque smooth change curve is fitted according to the initial pedal torque value and the shifting pedal torque value, and the target pedal torque value at the current moment is obtained; adjusting the assist ratio of the motor according to the target pedaling torque value so that the pedaling torque value is equal to the target pedaling torque value; Adjusting the power assist ratio of the motor within a first preset time before the predicted gear shifting moment so that the pedal force torque value within the first preset time is equal to the first preset pedal force torque value until the gear shifting is completed; Wherein, the initial pedaling torque value and the target pedaling torque value are both greater than the first preset pedaling torque value; Calculating the shift pedal torque value after the shift according to the predicted shift time includes: Obtain the shift torque difference of the motor; The initial pedal torque value and the shift torque difference value are summed, and when the sum result is greater than a first threshold value, the shift torque difference is corrected, and the sum of the corrected shift torque difference value and the initial pedal torque value is used as the shift pedal torque value after the gear shift.

2. The method for controlling the smoothness of motor gear shifting according to claim 1, characterized in that: The method of predicting the shifting time according to the initial pedal torque value and the wheel speed comprises the following sub-steps: Construct a neural network model with multi-layer perception mechanism; Obtaining the power assist ratio of the motor, and using the power assist ratio, initial pedal torque value and wheel speed as input parameters for prediction; Among them, the neural network model uses the Relu function as the activation function, Adam as the optimizer, and the mean square error function as the loss function.

3. The method for controlling the smoothness of motor gear shifting according to claim 2, characterized in that: The input parameters also include a riding intention prediction parameter, and the riding intention prediction parameter is obtained by the following steps: Based on pedal torque value and wheel speed; When the pedal force torque value is greater than the first preset torque, and the wheel speed is less than the first preset wheel speed, the riding intention prediction parameter is acceleration intention; When the pedaling torque value is equal to the first preset torque, or when the pedaling torque value is greater than the first preset torque and the wheel speed is greater than or equal to the first preset wheel speed, the riding intention prediction parameter is a uniform speed intention; When the pedaling torque value is less than the first preset torque, the riding intention prediction parameter is a deceleration intention.

4. The method for controlling the smoothness of motor gear shifting according to claim 1, characterized in that: Calculating the shift pedal torque value after the shift according to the predicted shift time includes: Obtain the shift torque difference of the motor; The initial pedal torque value and the shift torque difference value are summed to obtain the shift pedal torque value after the gear shift.

5. The method for controlling the smoothness of motor gear shifting according to any one of claims 1 to 4, characterized in that: After completing the gear shift, the following steps are also included: Setting a second preset time; The motor assist ratio is gradually adjusted within the second preset time so that the pedaling torque value approaches the initial pedaling torque value.

6. The method for controlling the smoothness of motor gear shifting according to claim 2, characterized in that: The step of fitting a time-dependent torque smooth change curve according to the initial pedal torque value and the gear shift pedal torque value includes: The duration from the current moment to the moment of the first preset time before the predicted gear shifting moment; The value of the initial pedal torque value and the value of the gear-shift pedal torque value are taken as two extreme values ​​of the function; A smooth transition function is constructed with time as the horizontal coordinate and the pedal torque value as the vertical coordinate, in which the torque value corresponding to each moment is the target torque value at that moment.

7. The method for controlling the smoothness of motor gear shifting according to claim 6, characterized in that: The smooth transition function includes: Acceleration shifting: ; Slow down and shift gears: ; in, is the initial pedal torque value; Shift pedal torque value; k is the compensation constant, and t is the current moment.

8. The method for controlling the smoothness of motor gear shifting according to claim 1, characterized in that: The method of adjusting the power assist ratio of the motor within a first preset time before the predicted gear shifting moment so that the pedaling torque value within the first preset time is equal to the first preset pedaling torque value until the gear shifting is completed comprises the following sub-steps: Get the current time and calculate the duration from the current time to the gear shifting time; When the time duration is less than or equal to the first preset time, the target pedaling torque is set to a first preset pedaling torque value; The assist ratio of the motor is adjusted so that the pedal force torque value at the current moment tends to the first preset pedal force torque value until the gear shift is completed.

9. A control system for smooth motor shifting, characterized in that: include: The acquisition module is used to detect and obtain the rider's initial pedal torque value and wheel speed in real time; a processing module, configured to receive the data transmitted by the acquisition module, predict the gear shifting moment according to the initial pedaling torque value and the wheel speed, calculate the gear shifting pedaling torque value after the gear shifting, and fit a time-related torque smoothing change curve according to the initial pedaling torque value and the gear shifting pedaling torque value, and obtain a target pedaling torque value at the current moment, and adjust the target pedaling torque value to a first preset pedaling torque value within a first preset time before the predicted gear shifting moment, until the gear shifting is completed; as well as The driving module is used to receive the target pedal torque value sent by the processing module, and adjust the power assistance ratio of the motor according to the target pedal torque value so that the pedal torque value is equal to the target pedal torque value.

10. A control device for smooth motor shifting, characterized in that: The device comprises: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform the operation of the motor shifting smoothness control method according to any one of claims 1 to 8.

Images