A control method, device and equipment for a mid-mounted motor

Abstract

The present invention discloses a control method, device and equipment for a mid-mounted motor. The control method includes: obtaining a first temperature influencing factor, motor output torque, motor speed, chainring output torque, control board temperature signal and sampling period; determining the gear prediction temperature according to the first temperature influencing factor, motor output torque, motor speed, chainring output torque, control board temperature signal and sampling period; when the gear prediction temperature is greater than the critical temperature threshold, determining the motor allowable torque according to the gear prediction temperature; outputting a torque control signal to the motor according to the motor allowable torque to control the motor to adjust the torque. The technical solution of the present invention ensures that the operation of the gear is maintained within a safe range, avoids noise caused by excessively high gear temperature, and avoids mid-mounted motor operation problems caused by high temperature, thereby extending the life of the mid-mounted motor and improving the reliability of the mid-mounted motor.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a control method, device and equipment for a mid-mounted motor. Background Art

[0002] The mid-mounted motor is the drive system of the electric-assisted bicycle. In order to improve the market competitiveness of the motor, some gears in the transmission system of the mid-mounted motor are made of plastic. This is because compared with metal materials, engineering plastics have comparable mechanical properties, better self-lubrication, lighter weight and lower cost.

[0003] Currently, mainstream mid-mounted motors on the market lack integrated thermal management systems or have incomplete ones. When motors operate at high temperatures for extended periods, the plastic gears, due to their inherent heat resistance, expand due to their inherent material properties. This can cause meshing noise during transmission. This noise significantly impacts the user's riding experience. Furthermore, this noise is caused by vibration, and prolonged vibration can cause wear on the gear teeth of the transmission system, reducing meshing accuracy and further increasing wear, shortening the lifespan of the gears and creating safety hazards during riding.

[0004] Existing control methods tend to focus on temperature prediction and control of the motor in the mid-mounted motor, without considering the management and protection of the key components, the plastic gears. Summary of the Invention

[0005] The present invention provides a control method, device and equipment for a mid-mounted motor to solve the problem in the prior art that the gearless thermal management system causes abnormal operation of gears at high temperatures and even affects the life of the mid-mounted motor.

[0006] According to a first aspect of the present invention, a control method for a mid-mounted motor is provided, wherein the mid-mounted motor includes a motor, a gear, and a control board;

[0007] Control methods include:

[0008] Obtaining a first temperature influencing factor, a motor output torque, a motor speed, a sprocket output torque, a control board temperature signal, and a sampling period;

[0009] Determine the predicted gear temperature based on the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal, and the sampling period;

[0010] When the gear predicted temperature is greater than the critical temperature threshold, the motor allowable torque is determined according to the gear predicted temperature;

[0011] Output a torque control signal to the motor according to the motor's allowable torque to control the motor to adjust the torque.

[0012] Optionally, determining the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal, and the sampling period includes:

[0013] Determine the gear loss power based on the motor output torque, motor speed and sprocket output torque;

[0014] Determine the gear heat dissipation power and the control board heat conduction power according to the first temperature influencing factor and the control board temperature signal;

[0015] Determine the instantaneous internal energy of the gear based on the gear loss power, gear heat dissipation power, control panel heat conduction power and sampling period;

[0016] The predicted gear temperature is determined based on the gear instantaneous internal energy and the first temperature influencing factor.

[0017] Optionally, the gear power loss is determined based on the motor output torque, the motor speed, and the sprocket output torque, including:

[0018] Determine the motor output power based on the motor output torque and the motor speed;

[0019] Determine the real-time transmission efficiency of the gear according to the motor speed, the output torque of the sprocket and the preset efficiency transmission function;

[0020] Determine the total gear power loss based on the gear's real-time transmission efficiency and the motor's output power;

[0021] The gear loss power is determined based on the total gear loss power and the gear loss coefficient.

[0022] Optionally, determining the gear heat dissipation power according to the first temperature influencing factor and the control board temperature signal includes:

[0023] Determine the inner cavity ambient temperature based on the control board temperature signal and the inner cavity temperature conversion coefficient;

[0024] Determining a second temperature influence factor according to the first temperature influence factor and the inner cavity ambient temperature;

[0025] The gear heat dissipation power is determined according to the second temperature influence factor and the heat dissipation coefficient.

[0026] Optionally, determining the thermal conductivity of the control panel according to the first temperature influencing factor and the control panel temperature signal includes:

[0027] determining a third temperature impact factor according to the first temperature impact factor and a control board temperature signal;

[0028] The heat conduction power of the control panel is determined according to the third temperature influencing factor and the electrically controlled thermal conductivity coefficient.

[0029] Optionally, determining the predicted gear temperature according to the instantaneous internal energy of the gear and the first temperature influencing factor includes:

[0030] Determine the gear temperature rise per unit time based on the gear instantaneous internal energy and gear heat capacity;

[0031] The predicted gear temperature is determined based on the gear temperature rise per unit time and the first temperature influencing factor.

[0032] Optionally, obtaining a first temperature influencing factor includes:

[0033] When the mid-mounted motor is started for the first time, the inner cavity temperature signal is obtained;

[0034] determining a first temperature influence factor according to the inner cavity temperature signal and the temperature influence function;

[0035] Alternatively, obtaining the first temperature influencing factor includes:

[0036] When the mid-mounted motor is not started for the first time, a predicted gear temperature is obtained and a first temperature influencing factor is determined according to the predicted gear temperature.

[0037] Optionally, the allowable torque of the motor is determined based on the predicted gear temperature, including:

[0038] Determine the allowable bending stress of the gear based on the predicted gear temperature;

[0039] Determine the allowable torque of the gear based on the allowable bending stress of the gear;

[0040] The motor allowable torque is determined based on the gear allowable torque and the preset reduction ratio.

[0041] According to a second aspect of the present invention, a control device for a mid-mounted motor is provided, which is used to execute a control method for a mid-mounted motor. The control device for a mid-mounted motor includes:

[0042] A signal acquisition module, configured to acquire a first temperature influencing factor, motor output torque, motor speed, crankset output torque, control board temperature signal, and a sampling period;

[0043] a predicted temperature determination module, configured to determine a predicted gear temperature based on a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period;

[0044] a motor torque determination module, configured to determine the motor allowable torque according to the gear predicted temperature when the gear predicted temperature is greater than a critical temperature threshold;

[0045] The motor torque adjustment module is used to output a torque control signal to the motor according to the motor allowable torque to control the motor to adjust the torque.

[0046] According to a third aspect of the present invention, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements a method for controlling a mid-mounted motor when executing the program.

[0047] The technical solution of the present invention determines the predicted gear temperature by utilizing the first temperature influencing factor, motor output torque, motor speed, chainring output torque, control board temperature signal and sampling period, and limits the motor torque when the predicted gear temperature exceeds the critical temperature threshold, thereby limiting the assist power of the mid-mounted motor, thereby ensuring that the operation of the gear is maintained within a safe range, avoiding noise due to excessively high gear temperature, and avoiding mid-mounted motor operation problems caused by high temperature, thereby extending the life of the mid-mounted motor and improving the reliability of the mid-mounted motor. Compared with other control methods, the method in the embodiment of the present invention does not add any hardware settings, reducing the cost of gear temperature prediction. In addition, the power limiting strategy takes into account both the user's riding experience and the thermal management of the gear, balancing the user experience and the limit requirements.

[0048] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 This is a schematic diagram of a connection between a mid-mounted motor and a crankset according to an embodiment of the present invention;

[0051] Figure 2 2. This is a schematic diagram of the internal connection of a mid-mounted motor from a first perspective according to an embodiment of the present invention;

[0052] Figure 3 2 is a schematic diagram of the internal connection of a mid-mounted motor according to a second perspective of an embodiment of the present invention;

[0053] Figure 4 is a flow chart of a first mid-mounted motor control method provided by an embodiment of the present invention;

[0054] Figure 5 is a graph showing the relationship between the maximum output torque of a motor and time according to an embodiment of the present invention;

[0055] Figure 6 is a graph showing the relationship between the real-time temperature of a gear and time according to an embodiment of the present invention;

[0056] Figure 7 is a graph showing the relationship between steady-state assist torque and time according to an embodiment of the present invention;

[0057] Figure 8 is a graph showing the relationship between controller temperature and time according to an embodiment of the present invention;

[0058] Figure 9 is a flow chart of a second method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

[0059] Figure 10 is a flow chart of a third method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

[0060] Figure 11 is a flow chart of a fourth method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

[0061] Figure 12 is a flow chart of a fifth method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

[0062] Figure 13 is a flow chart of a sixth method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

[0063] Figure 14 is a flow chart of a seventh method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

[0064] Figure 15 is a flow chart of an eighth method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

[0065] Figure 16 is a flow chart of a ninth method for controlling a mid-mounted motor according to an embodiment of the present invention;

[0066] Figure 17 is a graph showing the relationship between temperature and gear stress and strain according to an embodiment of the present invention;

[0067] Figure 18 is a relationship diagram between temperature and gear elastic modulus provided according to an embodiment of the present invention;

[0068] Figure 19 is a graph showing the relationship between the predicted gear temperature and the crankset output torque according to an embodiment of the present invention;

[0069] Figure 20 2 is a connection diagram of a control device for a mid-mounted motor according to an embodiment of the present invention;

[0070] Figure 21 1 is a schematic diagram of the structure of an electronic device for a control method for a mid-mounted motor provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0071] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0072] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0073] Figure 1 This is a schematic diagram of the connection between a mid-mounted motor and a crankset according to an embodiment of the present invention. Figure 2 1 is a schematic diagram of the internal connection of a mid-mounted motor from a first perspective according to an embodiment of the present invention. Figure 3 1 is a schematic diagram of the internal connection of a mid-mounted motor according to a second perspective. Figure 1 、 Figure 2 and Figure 3 As shown, the central motor 1 includes: a motor 11, a gear 12 and a control board 13;

[0074] The mid-mounted motor 1 can be used to provide power for an electric-assisted bicycle. The mid-mounted motor 1 includes a motor 11, a gear 12, and a control board 13. The control board 13 is electrically connected to the motor 11, which is in a transmission connection with the gear 12. The control board 13 controls the rotation of the motor 11, which in turn drives the gear 12. In some embodiments, the gear 12 includes a primary driven wheel 121, a secondary driving wheel 122, a secondary driven wheel 123, a tertiary driving wheel 124, and a tertiary driven wheel 125. Among them, the first-stage driven wheel 121 is transmission-connected to the motor 11 via the motor shaft 111, the second-stage driving wheel 122 is coaxially connected to the first-stage driven wheel 121, and the rotation of the first-stage driven wheel 121 drives the rotation of the second-stage driving wheel 122. The second-stage driven wheel 123 is transmission-connected to the second-stage driving wheel 122, and the second-stage driving wheel 122 drives the second-stage driven wheel 123 to rotate. The third-stage driving wheel 124 is coaxially connected to the second-stage driven wheel 123, and the second-stage driven wheel 123 drives the third-stage driving wheel 124 to rotate. The third-stage driving wheel 124 is transmission-connected to the third-stage driven wheel 125, and the third-stage driving wheel 124 drives the third-stage driven wheel 125 to rotate. The chainring 2 of the electric power-assisted bicycle is coaxially connected to the third-stage driven wheel 125 via the central shaft 14. The third-stage driven wheel 125 drives the chainring 2 to rotate, thereby achieving power assistance for the electric power-assisted bicycle. In actual application, considering the mechanical properties, lubricity, weight and cost of the gears 12 inside the mid-mounted motor 1, some gears 12 in the mid-mounted motor 1 are often made of plastic, such as the primary driven wheel 121. However, the plastic gears 12 have poor heat resistance, which leads to thermal expansion of the plastic gears 12 in a high temperature environment. When the thermally expanded gears 12 are engaged, noise and tooth surface wear will occur, which will reduce the life of the mid-mounted motor 1 and pose a safety hazard to riding. Therefore, a control method for the mid-mounted motor 1 is provided in an embodiment of the present invention, which limits the power assist of the mid-mounted motor 1 based on the temperature of the gears 12 in the mid-mounted motor 1. Figure 4 This is a flow chart of a first mid-mounted motor control method according to an embodiment of the present invention, Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, the control method includes:

[0075] S10, obtaining a first temperature influencing factor, a motor output torque, a motor speed, a sprocket output torque, a control board temperature signal, and a sampling period.

[0076] The first temperature influencing factor may be the initial predicted temperature of the gear 12. Since the gear 12 is disposed within the inner cavity of the center motor 1, when the center motor 1 is first started, the initial predicted temperature of the gear 12 may be the ambient temperature of the gear 12, i.e., the temperature within the inner cavity of the center motor 1. This temperature may be acquired using a temperature sensor disposed on the center shaft 14. When the center motor 1 is not first started, the initial predicted temperature of the gear 12 may be the predicted gear temperature during the previous acquisition cycle. It is understood that the gear 12 in this embodiment of the present invention may be any gear 12 within the center motor 1, and the position of the gear 12 is not specifically limited.

[0077] The control board 13 is electrically connected to the motor 11 , and the motor output torque, motor speed, and crankset output torque can be obtained through the control current of the control board 13 .

[0078] The control board temperature signal can be obtained by a temperature sensor provided on the control board 13. The sampling period can be the sampling period of the first temperature influence factor, the motor output torque, the motor speed, the chainring output torque, and the control board temperature signal. To ensure the accuracy of the calculation, the sampling periods of the first temperature influence factor, the motor output torque, the motor speed, the chainring output torque, and the control board temperature signal can be set to the same sampling period.

[0079] S11 , determining a predicted gear temperature according to a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0080] The gear power loss can be determined using the motor output torque, motor speed, and crankset output torque. Since the first temperature influencing factor represents the initial predicted temperature of gear 12 and the control board temperature signal represents the temperature of control board 13, the first temperature influencing factor and the control board temperature signal can be used to determine the effect of the control board temperature on gear 12 and the effect of the gear 12 temperature on the heat dissipation of the internal cavity. Based on the gear power loss, the effect of the control board 13 temperature on gear 12, and the effect of the gear 12 temperature on the heat dissipation of the internal cavity, the predicted gear temperature is determined. This predicted gear temperature represents the predicted gear temperature during the current acquisition cycle.

[0081] S12. When the predicted gear temperature is greater than a critical temperature threshold, determine the allowable motor torque according to the predicted gear temperature.

[0082] The critical temperature threshold can be a temperature value that affects the normal operation of gear 12 and the life of mid-mounted motor 1. When the predicted gear temperature exceeds the critical temperature threshold, it indicates that the temperature of gear 12 is too high, affecting the normal operation of mid-mounted motor 1. Motor torque intervention is required to prevent the temperature of gear 12 from continuing to rise. Therefore, the predicted gear temperature is used to determine the allowable motor torque. The allowable motor torque is the maximum torque that motor 11 can output at the current predicted gear temperature.

[0083] S13: Output a torque control signal to the motor according to the motor's allowable torque to control the motor to adjust the torque.

[0084] Among them, since the motor allowable torque is the maximum torque of the motor 11 at the predicted temperature of the gear, the torque control signal is output to the motor 11 according to the motor allowable torque, controlling the motor 11 to reduce the torque, thereby reducing the torque of the gear 12, thereby reducing the speed of the gear 12 and the temperature of the gear 12.

[0085] Specifically, the first temperature influencing factor, motor output torque, motor speed, chainring output torque, and control board temperature signal within the sampling period are first acquired. A predicted gear temperature A°C is determined based on the first temperature influencing factor, motor output torque, motor speed, chainring output torque, control board temperature signal, and sampling period. A determination is made as to whether the predicted gear temperature A°C is greater than a critical temperature threshold value A0°C. When A°C>A0°C, the maximum output torque of the motor 11 allowed at that temperature is determined based on the predicted gear temperature A°C. The current motor output torque is adjusted based on the motor's allowable torque to reduce the temperature of the gear 12, ensure normal operation of the gear 12, and extend the service life of the mid-mounted motor 1. It will be understood that the predicted gear temperature in the technical solution of the embodiment of the present invention is a real-time prediction. When A°C≤A0°C, the first temperature influencing factor, motor output torque, motor speed, chainring output torque, and control board temperature signal are continuously acquired, and the torque of the motor 11 is not controlled.

[0086] For example, since motor 11 is in transmission connection with gear 12, which is in transmission connection with chainring 2, the adjustment result of motor 11 is ultimately directly reflected in the chainring output torque. Under the chainring operating conditions of 80 rpm and 100 Nm, two cases were tested with and without the control method of the embodiment of the present invention, and the data was compared. The results and analysis are as follows:

[0087] (1) Comparison of the duration of the motor's maximum allowable torque:

[0088] in, Figure 5 is a graph showing the relationship between the maximum output torque of the motor and time according to an embodiment of the present invention. Figure 5 As shown, the greater the maximum allowable torque of the motor, the faster the gear will heat up. When the engine is started at the working condition of 80rpm and 100Nm of the chainring, the maximum allowable torque of the motor is 2.6Nm at the initial moment. After introducing the control method of the embodiment of the present invention, the duration of the maximum allowable torque of the motor is reduced from 11.85min to 5.3min. This is because the predicted temperature of the gear reaches the critical temperature threshold, and the power of the entire machine is reduced by reducing the motor torque, thereby protecting the gear.

[0089] (2) Real-time temperature comparison of gears:

[0090] Figure 6 is a graph showing the relationship between the real-time temperature of the gear and time according to an embodiment of the present invention, such as Figure 6 As shown, after the control method of the embodiment of the present invention is introduced, the real-time temperature of the gear is reduced from 108.8°C to 96.7°C, a decrease of 12.1°C, thereby achieving the purpose of cooling the gear and protecting the normal operation of the gear.

[0091] (3) Steady-state assist torque comparison:

[0092] in, Figure 7 is a diagram showing the relationship between the steady-state assist torque and time according to an embodiment of the present invention, such as Figure 7 As shown, the steady-state assist torque can be the assist torque of the mid-mounted motor. After introducing the control method of the embodiment of the invention, the steady-state torque drops from 60 Nm to 55 Nm, reducing the power consumption in the steady state and protecting the gears.

[0093] (4) Comparison of controller temperature in steady state:

[0094] in, Figure 8 is a diagram showing the relationship between controller temperature and time according to an embodiment of the present invention. Figure 8 As shown, the controller may be a control system for a mid-mounted motor, including a control board. By introducing the control method of an embodiment of the present invention, the steady-state temperature of the controller drops from 90.8°C to 83.3°C, a decrease of 7.5°C. At the same time, the controller is also protected to avoid the risk of failure.

[0095] The technical solution of the embodiment of the present invention determines the predicted gear temperature by utilizing the first temperature influencing factor, motor output torque, motor speed, chainring output torque, control board temperature signal and sampling period, and limits the motor torque when the predicted gear temperature exceeds the critical temperature threshold, thereby limiting the assist power of the mid-mounted motor, thereby ensuring that the operation of the gear is maintained within a safe range, avoiding noise due to excessive gear temperature, and avoiding mid-mounted motor operation problems caused by high temperature, extending the life of the mid-mounted motor, and improving the reliability of the mid-mounted motor. Compared with other control methods, the method in the embodiment of the present invention does not add any hardware settings, reducing the cost of gear temperature prediction. In addition, the power limiting strategy takes into account both the user's riding experience and the thermal management of the gear, balancing the user experience and the limit requirements.

[0096] Based on the above embodiments, Figure 9 is a flow chart of a second method for controlling a mid-mounted motor according to an embodiment of the present invention, Figure 1 、 Figure 2 、 Figure 3 and Figure 9 As shown, the control method includes:

[0097] S20: Obtain a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0098] S21. Determine the gear loss power according to the motor output torque, the motor speed, and the sprocket output torque.

[0099] The motor output power can be determined based on the motor output torque and motor speed. Theoretically, all of the motor output power should be transmitted to gear 12. Some of this gear power is transmitted to chainring 2, while some is lost. This lost power is converted into internal energy and dissipated as heat. Therefore, the gear power loss can be determined based on the motor output torque, motor speed, and chainring output torque. This gear power loss is related to the gear's internal energy, that is, the temperature of gear 12.

[0100] S22. Determine the gear heat dissipation power and the control board heat conduction power according to the first temperature influencing factor and the control board temperature signal.

[0101] The first temperature influencing factor represents the initial predicted gear temperature, which is affected by gear 12 itself. Gear 12 also dissipates heat during operation, transferring it to the inner cavity. Control board 13 also dissipates heat during operation, and this heat also affects the temperature of gear 12. Therefore, the first temperature influencing factor and the control board temperature signal are used to determine the gear heat dissipation power and the control board thermal conductivity power.

[0102] S23. Determine the instantaneous internal energy of the gear according to the gear loss power, the gear heat dissipation power, the control panel heat conduction power and the sampling period.

[0103] Among them, since the temperature of the gear 12 is affected by the gear loss power, gear heat dissipation power, and control board thermal power, the gear instantaneous internal energy can be determined by the gear loss power, gear heat dissipation power, control board thermal power and sampling period. The gear loss power P loss , gear heat dissipation power P dispat , control board thermal power P conduct , sampling period x and gear instantaneous internal energy Q instant Q instant =(P loss -P dispat +P conduct )*x.

[0104] S24. Determine the predicted gear temperature according to the instantaneous internal energy of the gear and the first temperature influencing factor.

[0105] Among them, since the gear instantaneous internal energy affects the temperature rise of the gear 12 during the sampling period, and the first temperature influence factor is the initial predicted temperature of the gear, the gear predicted temperature can be determined based on the gear instantaneous internal energy and the first temperature influence factor.

[0106] S25. When the predicted gear temperature is greater than a critical temperature threshold, determine the motor allowable torque according to the predicted gear temperature.

[0107] S26 , outputting a torque control signal to the motor according to the allowable torque of the motor to control the motor to adjust the torque.

[0108] The technical solution of the embodiment of the present invention determines the gear loss power based on the motor output torque, motor speed and chainring output torque, determines the gear heat dissipation power and control board thermal conductivity power based on the first temperature influencing factor and the control board temperature signal, and determines the gear instantaneous internal energy based on the gear loss power, gear heat dissipation power, control board thermal conductivity power and sampling period, that is, the temperature rise of the gear within the sampling period, and determines the gear predicted temperature based on the gear instantaneous internal energy and the first temperature influencing factor, thereby realizing the prediction of gear temperature.

[0109] Based on the above embodiments, Figure 10 FIG. 1 is a flow chart of a third method for controlling a mid-mounted motor according to an embodiment of the present invention. Figure 10 As shown, the control method includes:

[0110] S30: Obtain a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0111] S31 . Determine the motor output power according to the motor output torque and the motor speed.

[0112] The motor output torque T, the motor speed n, and the motor output power P satisfy P=n*T / 9.55.

[0113] S32: Determine the real-time transmission efficiency of the gear according to the motor speed, the output torque of the sprocket and a preset efficiency transmission function.

[0114] The preset efficiency transmission function can be a relationship between the crankset output torque, motor speed, and the real-time gear transmission efficiency, determined based on the current motor-gear-crankset transmission ratio. The real-time gear transmission efficiency η = f(n, Tz) can be determined using the real-time motor speed n and crankset output torque Tz.

[0115] S33. Determine the total gear power loss according to the real-time transmission efficiency of the gear and the motor output power.

[0116] Among them, since part of the motor output power is converted into gear transmission power and part is converted into the internal energy of the gear, the total gear loss power can be determined according to the gear real-time transmission efficiency and motor output power. The gear real-time transmission efficiency η, motor output power P and gear total loss power P are totaloss Between satisfying P totaloss =P*(1-η).

[0117] S34. Determine the gear loss power according to the total gear loss power and the gear loss coefficient.

[0118] Among them, the total gear loss power is the loss power of all gears. When the control method only predicts a certain gear of the central motor, the gear loss power of the corresponding gear needs to be determined based on the total gear loss power. At this time, the gear loss coefficient of the corresponding gear can be obtained according to the calibration method. The gear loss coefficient represents the proportion of the gear in the total gear loss. Therefore, the total gear loss power P totaloss , gear loss coefficient and gear power loss P loss Satisfaction between

[0119] S35. Determine the gear heat dissipation power and the control board heat conduction power according to the first temperature influencing factor and the control board temperature signal.

[0120] S36. Determine the instantaneous internal energy of the gear according to the gear loss power, the gear heat dissipation power, the control panel heat conduction power, and the sampling period.

[0121] S37. Determine the predicted gear temperature according to the instantaneous internal energy of the gear and the first temperature influencing factor.

[0122] S38. When the predicted gear temperature is greater than a critical temperature threshold, determine the motor allowable torque according to the predicted gear temperature.

[0123] S39: Output a torque control signal to the motor according to the allowable torque of the motor to control the motor to adjust the torque.

[0124] The technical solution of the embodiment of the present invention determines the corresponding gear loss power, that is, the power converted into heat energy by the gear according to the motor output torque, motor speed, and chainring output torque, so as to subsequently accurately predict the temperature of the corresponding gear.

[0125] Based on the above embodiments, Figure 11 : is a flow chart of a fourth method for controlling a mid-mounted motor according to an embodiment of the present invention. Figure 11 As shown, the control method includes:

[0126] S40: Obtain a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0127] S41. Determine the gear loss power according to the motor output torque, the motor speed, and the sprocket output torque.

[0128] S42. Determine the inner cavity ambient temperature according to the control board temperature signal and the inner cavity temperature conversion coefficient.

[0129] Among them, the inner cavity ambient temperature can be determined based on the control board temperature signal and the inner cavity temperature conversion coefficient. Since the temperature sensor corresponding to the control board temperature signal is set on the control board, the temperature on the control board can be collected. The control board is directly connected to the inner cavity. The control board temperature signal and the inner cavity temperature conversion coefficient can be used to determine the impact of the control board temperature on the inner cavity temperature. NTC , the inner cavity temperature conversion coefficient a and the inner cavity ambient temperature T inner Between T inner =a*Temp NTC .

[0130] S43: Determine a second temperature impact factor according to the first temperature impact factor and the inner cavity ambient temperature.

[0131] Among them, the second temperature influence factor can be the difference between the first temperature influence factor and the inner cavity ambient temperature, that is, the difference between the initial predicted temperature of the gear and the inner cavity ambient temperature. The larger the second temperature influence factor, the greater the influence of the gear temperature on the inner cavity ambient temperature. The first temperature influence factor K1, the inner cavity ambient temperature T nner The second temperature influence factor K2 satisfies K2=K1-T nner .

[0132] S44. Determine the gear heat dissipation power according to the second temperature influence factor and the heat dissipation coefficient.

[0133] Among them, the heat dissipation coefficient is the heat transfer coefficient from the corresponding gear to the inner cavity. The second temperature influence factor K2, the heat dissipation coefficient and gear cooling power P dispat Satisfaction between Wherein, e is a constant, and in some embodiments, 0.5≤e≤1.5, thereby determining the heat transfer power of the gear to the inner cavity.

[0134] S45. Determine the thermal conductivity of the control panel according to the first temperature influencing factor and the control panel temperature signal.

[0135] S46. Determine the instantaneous internal energy of the gear according to the gear loss power, the gear heat dissipation power, the control panel heat conduction power, and the sampling period.

[0136] S47. Determine the predicted gear temperature according to the instantaneous internal energy of the gear and the first temperature influencing factor.

[0137] S48. When the predicted gear temperature is greater than a critical temperature threshold, determine the motor allowable torque according to the predicted gear temperature.

[0138] S49: Output a torque control signal to the motor according to the motor's allowable torque to control the motor to adjust the torque.

[0139] The technical solution of the embodiment of the present invention determines the gear heat dissipation power by controlling the board temperature signal, the inner cavity temperature conversion coefficient, the first temperature influence factor and the heat dissipation coefficient, and determines that the gear heating temperature is affected by the combined effects of the gear loss power and the gear heat dissipation power, so as to accurately predict the temperature of the corresponding gear in the subsequent process.

[0140] Based on the above embodiments, Figure 12 : is a flow chart of a fifth method for controlling a mid-mounted motor according to an embodiment of the present invention. Figure 12 As shown, the control method includes:

[0141] S50: Obtain a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0142] S51 : Determine the gear loss power according to the motor output torque, the motor speed, and the sprocket output torque.

[0143] S52. Determine the gear heat dissipation power according to the first temperature influencing factor and the control board temperature signal.

[0144] S53, determine the third temperature influence factor based on the first temperature influence factor and the control board temperature signal. The third temperature influence factor can be the difference between the first temperature influence factor and the control board temperature signal, that is, the difference between the initial predicted temperature of the gear and the control board temperature. Since the control board also dissipates heat during the operation of the central motor, the temperature of the control board will also affect the temperature rise of the gear. Therefore, the first temperature influence factor and the control board temperature signal are used to determine the third temperature influence factor. The first temperature influence factor K1, the control board temperature signal Temp NTC And the third temperature influence factor K3 satisfies K3=Temp NTC -K1.

[0145] S54. Determine the thermal conductivity power of the control panel according to the third temperature influencing factor and the electrically controlled thermal conductivity coefficient.

[0146] The heat conduction power of the control board can be the heat conduction power of the control board to the gear. And the control board thermal power P conduct Satisfaction between Wherein, m is a constant. In some embodiments, 0.5≤m≤1.5.

[0147] S55. Determine the instantaneous internal energy of the gear according to the gear loss power, the gear heat dissipation power, the control panel heat conduction power, and the sampling period.

[0148] S56. Determine the predicted gear temperature according to the instantaneous internal energy of the gear and the first temperature influencing factor.

[0149] S57: When the predicted gear temperature is greater than a critical temperature threshold, determine the motor allowable torque according to the predicted gear temperature.

[0150] S58 : Output a torque control signal to the motor according to the allowable torque of the motor to control the motor to adjust the torque.

[0151] The technical solution of the embodiment of the present invention determines the thermal conductivity power of the control board through the first temperature influencing factor, the control board temperature signal, and the electrically controlled thermal conductivity coefficient, and determines that the heating temperature of the gear is affected by the combined effects of the gear loss power, the gear heat dissipation power, and the thermal conductivity power of the control board, so as to subsequently accurately predict the temperature of the corresponding gear.

[0152] Based on the above embodiments, Figure 13 : is a flow chart of a sixth method for controlling a mid-mounted motor according to an embodiment of the present invention. Figure 13 As shown, the control method includes:

[0153] S60: Obtain a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0154] S61 : Determine the gear power loss according to the motor output torque, the motor speed, and the sprocket output torque.

[0155] S62. Determine the gear heat dissipation power and the control board heat conduction power according to the first temperature influencing factor and the control board temperature signal.

[0156] S63. Determine the instantaneous internal energy of the gear according to the gear loss power, the gear heat dissipation power, the control panel heat conduction power, and the sampling period.

[0157] S64. Determine the gear temperature rise per unit time based on the gear instantaneous internal energy and the gear heat capacity.

[0158] Among them, the gear temperature rise per unit time can be the gear temperature rise value within the sampling period. Since the gear instantaneous internal energy can be the internal energy of the gear converted into temperature, the gear temperature rise per unit time can be determined based on the gear instantaneous internal energy and gear heat capacity. The gear instantaneous internal energy Q instant , the gear heat capacity s and the gear unit time temperature rise Δt satisfy Δt=Q instant / s.

[0159] S65. Determine the predicted gear temperature according to the gear temperature rise per unit time and the first temperature influencing factor.

[0160] Among them, since the gear unit time temperature rise is the temperature rise of the gear in the acquisition period, and the first temperature influence factor is the initial predicted temperature of the gear, the gear predicted temperature can be determined according to the gear unit time temperature rise and the first temperature influence factor. The gear unit time temperature rise Δt, the first temperature influence factor K1 and the gear predicted temperature T pred Between T pred =K1+Δt.

[0161] S66. When the predicted gear temperature is greater than a critical temperature threshold, determine the motor allowable torque according to the predicted gear temperature.

[0162] S67: Output a torque control signal to the motor according to the motor's allowable torque to control the motor to adjust the torque.

[0163] The technical solution of the embodiment of the present invention determines the predicted gear temperature through the gear instantaneous internal energy, gear heat capacity and the first temperature influencing factor, so that the predicted gear temperature is the real-time temperature under the acquisition cycle, thereby achieving the purpose of real-time temperature prediction of the corresponding gear.

[0164] Based on the above embodiments, Figure 14 : is a flow chart of a seventh method for controlling a mid-mounted motor according to an embodiment of the present invention. Figure 14 As shown, the control method includes:

[0165] S70: When the mid-mounted motor is started for the first time, obtain an inner cavity temperature signal.

[0166] When the central motor is first started, the thermal impact on the gears is mainly due to the internal cavity temperature, so an internal cavity temperature signal is obtained at this time. The temperature sensor corresponding to the internal cavity temperature signal can be installed on the central shaft.

[0167] S71. Determine a first temperature influence factor according to the inner cavity temperature signal and the temperature influence function.

[0168] Among them, since the temperature sensor directly obtains the temperature of the inner cavity, the temperature influence function is a function of the influence of the inner cavity temperature on the gear temperature. Therefore, the initial predicted temperature of the gear, that is, the first temperature influence factor, can be determined by the inner cavity temperature signal and the temperature influence function.

[0169] S72: Obtain the motor output torque, motor speed, sprocket output torque, control board temperature signal, and sampling period.

[0170] S73. Determine the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal, and the sampling period.

[0171] S74. When the predicted gear temperature is greater than a critical temperature threshold, determine the motor allowable torque according to the predicted gear temperature.

[0172] S75 , outputting a torque control signal to the motor according to the allowable torque of the motor to control the motor to adjust the torque.

[0173] or, Figure 15 : is a flow chart of an eighth method for controlling a mid-mounted motor according to an embodiment of the present invention. Figure 15 As shown, the control method includes:

[0174] S80: When the mid-mounted motor is not started for the first time, obtain a predicted gear temperature and determine a first temperature influencing factor according to the predicted gear temperature.

[0175] Among them, when the intermediate motor is not started for the first time, it means that the gear and the control board have changed due to the previous working temperature. At this time, the initial predicted temperature of the gear is affected not only by the inner cavity temperature, but also by the control board temperature and the gear temperature itself. Therefore, the initial predicted temperature of the gear can be the gear predicted temperature of the previous acquisition cycle, and the gear predicted temperature is used as the first temperature influencing factor.

[0176] S81. Obtain the motor output torque, motor speed, sprocket output torque, control board temperature signal, and sampling period.

[0177] S82: Determine the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal, and the sampling period.

[0178] S83. When the predicted gear temperature is greater than a critical temperature threshold, determine the motor allowable torque according to the predicted gear temperature.

[0179] S84: Output a torque control signal to the motor according to the motor's allowable torque to control the motor to adjust the torque.

[0180] It is understood that the first temperature impact factor in the embodiments of the present invention is derived from two sources: the first, when the center motor is first started. In this case, the first temperature impact factor is solely related to the internal cavity temperature signal and is therefore determined based on the internal cavity temperature signal and the temperature impact function. The second, when the center motor is not first started, the first temperature impact factor is the predicted gear temperature from the previous acquisition cycle. The technical solution of the embodiments of the present invention fully considers the thermal effects within the center motor, improving the accuracy of the predicted gear temperature.

[0181] Based on the above embodiments, Figure 16 : is a flow chart of a ninth method for controlling a mid-mounted motor according to an embodiment of the present invention. Figure 16 As shown, the control method includes:

[0182] S90: Obtain a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0183] S91. Determine a predicted gear temperature according to a first temperature influencing factor, a motor output torque, a motor speed, a crankset output torque, a control board temperature signal, and a sampling period.

[0184] S92. When the predicted gear temperature is greater than a critical temperature threshold, determine the allowable motor torque according to the predicted gear temperature.

[0185] S93. Determine the allowable bending stress of the gear based on the predicted gear temperature.

[0186] in, Figure 17 is a graph showing the relationship between temperature and gear stress and strain according to an embodiment of the present invention. Figure 17 As shown in the figure, the stress and strain of the gear at different temperatures are different. Especially when the gear is made of plastic, the stress and strain at different temperatures can be shown as Figure 17 As shown. Similarly, Figure 18 is a relationship diagram between temperature and gear elastic modulus provided according to an embodiment of the present invention, such as Figure 18 As shown in the figure, the elastic modulus of a gear varies at different temperatures. The allowable bending stress of a gear is determined by combining the gear stress change and the elastic modulus. This represents the ultimate bending stress of the gear during operation. If the stress exceeds this limit, the gear reliability decreases, posing a safety hazard. Therefore, by determining the allowable bending stress of a gear based on its predicted temperature, we can determine the maximum bending stress the gear can withstand at that temperature.

[0187] S94. Determine the allowable torque of the gear based on the allowable bending stress of the gear.

[0188] Among them, the allowable bending stress of the gear can be converted into the allowable torque of the gear, that is, the maximum torque at which the gear can operate at this temperature.

[0189] S95: Determine the motor allowable torque according to the gear allowable torque and the preset reduction ratio.

[0190] The preset reduction ratio is determined by the transmission ratio of the motor and the gear. The motor allowable torque is determined based on the gear allowable torque and the preset reduction ratio, so that by limiting the motor torque, the gear torque can be limited, thereby changing the torque of the gear at that temperature, and thus changing the toothed disc torque. In some embodiments, since the preset reduction ratio is fixed, the toothed disc output torque only changes with the change of the gear predicted temperature, so the toothed disc output torque Tz is related to the gear predicted temperature T pred The relationship between them can be Tz = -1.1129*T pred +154.77. Figure 19is a relationship diagram between the gear predicted temperature and the crankset output torque provided by an embodiment of the present invention, such as Figure 19 As shown, based on this relationship, a relationship diagram between the gear predicted temperature and the output torque of the sprocket can be generated.

[0191] The technical solution of the present invention calculates the allowable bending stress of the gear when the predicted temperature of the gear exceeds a critical temperature threshold, calculates the allowable torque of the motor based on the allowable bending stress of the gear, limits the motor torque based on the allowable torque of the motor, and further limits the assist power of the mid-mounted motor, thereby ensuring that the operation of the gear is maintained within a safe range, avoiding noise caused by excessively high gear temperature, and avoiding mid-mounted motor operation problems caused by high temperature, thereby extending the life of the mid-mounted motor and improving the reliability of the mid-mounted motor.

[0192] Based on the same inventive concept, Figure 20 : is a connection diagram of a control device for a mid-mounted motor according to an embodiment of the present invention. Figure 20 As shown, an embodiment of the present invention further provides a control device for a mid-mounted motor, which is used to execute a control method for a mid-mounted motor. The control device for a mid-mounted motor includes:

[0193] The signal acquisition module 100 is used to obtain the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal and the sampling period.

[0194] The predicted temperature determination module 200 is used to determine the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal and the sampling period.

[0195] The motor torque determination module 300 is configured to determine the motor allowable torque according to the gear predicted temperature when the gear predicted temperature is greater than a critical temperature threshold.

[0196] The motor torque adjustment module 400 is configured to output a torque control signal to the motor according to the motor's allowable torque, so as to control the motor to adjust the torque.

[0197] Specifically, the signal acquisition module 100 first acquires a first temperature influencing factor, motor output torque, motor speed, crankset output torque, control board temperature signal, and sampling period. The predicted temperature determination module 200 then determines the predicted gear temperature based on the first temperature influencing factor, motor output torque, motor speed, crankset output torque, control board temperature signal, and sampling period. When the predicted gear temperature is greater than a critical temperature threshold, the motor torque determination module 300 then determines the motor allowable torque based on the predicted gear temperature. The motor torque adjustment module 400 then outputs a torque control signal to the motor based on the motor allowable torque to control the motor's adjusted torque.

[0198] The technical solution of the embodiment of the present invention limits the assist power of the mid-mounted motor when the predicted gear temperature is too high by setting a signal acquisition module, a predicted temperature determination module, a motor torque determination module and a motor torque adjustment module, thereby ensuring that the operation of the gear is maintained within a safe range, avoiding noise caused by excessively high gear temperature, and avoiding mid-mounted motor operation problems caused by high temperature, thereby extending the life of the mid-mounted motor and improving the reliability of the mid-mounted motor.

[0199] Based on the same inventive concept, an embodiment of the present invention further provides a computer device, Figure 21 FIG. 1 is a schematic diagram of an electronic device structure for a control method for a mid-mounted motor according to an embodiment of the present invention. Figure 21 As shown, it includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the program, a control method for the mid-mounted motor is implemented.

[0200] Among them, electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only for example and are not intended to limit the implementation of the invention described and / or claimed herein.

[0201] like Figure 21 As shown, the electronic device 50 includes at least one processor 51 and a memory, such as a read-only memory (ROM) 52, a random access memory (RAM) 53, etc., which is communicatively connected to the at least one processor 51. The memory stores a computer program that can be executed by the at least one processor. The processor 51 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 52 or the computer program loaded from the storage unit 58 into the random access memory (RAM) 53. Various programs and data required for the operation of the electronic device 50 can also be stored in the RAM 53. The processor 51, ROM 52, and RAM 53 are connected to each other via a bus 54. An input / output (I / O) interface 55 is also connected to the bus 54.

[0202] Multiple components in the electronic device 50 are connected to the I / O interface 55, including an input unit 56, such as a keyboard, a mouse, etc.; an output unit 57, such as various types of displays, speakers, etc.; a storage unit 58, such as a magnetic disk, an optical disk, etc.; and a communication unit 59, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 59 allows the electronic device 50 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0203] The processor 51 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the processor 51 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any other suitable processor, controller, microcontroller, etc. The processor 51 executes the various methods and processes described above, such as the control method applied to the mid-mounted motor.

[0204] Based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which implements a method for controlling a mid-mounted motor when the program is executed by a processor.

[0205] Of course, the computer-readable storage medium provided in the embodiment of the present invention, whose computer-executable instructions are not limited to the method operations described above, can also perform the relevant operations in the control method of the mid-mounted motor provided in any embodiment of the present invention, and continue to refer to Figure 21 As shown, it is tangibly contained in a computer-readable storage medium, such as storage unit 58. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 50 via ROM 52 and / or communication unit 59. When the computer program is loaded into RAM 53 and executed by processor 51, one or more steps of the control method for mid-mounted motors described above can be performed. Alternatively, in other embodiments, processor 51 can be configured to execute the control method for mid-mounted motors in any other suitable manner (e.g., via firmware).

[0206] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0207] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0208] In the context of an embodiment of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. A computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. A more specific example of a machine-readable storage medium can include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0209] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0210] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0211] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for controlling a mid-mounted motor, characterized in that: The mid-mounted motor includes a motor, a gear and a control board; The control method includes: Obtaining a first temperature influencing factor, a motor output torque, a motor speed, a sprocket output torque, a control board temperature signal, and a sampling period; determining a predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal, and the sampling period; When the gear predicted temperature is greater than a critical temperature threshold, determining the motor allowable torque according to the gear predicted temperature; Outputting a torque control signal to the motor according to the motor allowable torque to control the motor to adjust the torque; Obtain the first temperature impact factor, including: When the mid-mounted motor is started for the first time, obtaining an inner cavity temperature signal; Determining a first temperature influence factor according to the inner cavity temperature signal and a temperature influence function; wherein the temperature influence function is a function of the influence of the inner cavity temperature on the gear temperature; Alternatively, obtaining the first temperature influencing factor includes: When the central motor is not started for the first time, the gear predicted temperature of the last sampling period is obtained and the first temperature influencing factor is determined according to the gear predicted temperature of the last sampling period.

2. The control method according to claim 1, characterized in that: Determining the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal, and the sampling period includes: determining gear loss power according to the motor output torque, the motor speed, and the crankset output torque; Determining the gear heat dissipation power and the control board heat conduction power according to the first temperature influencing factor and the control board temperature signal; Determine the instantaneous internal energy of the gear according to the gear loss power, the gear heat dissipation power, the control board heat conduction power and the sampling period; The predicted gear temperature is determined according to the instantaneous internal energy of the gear and the first temperature influencing factor.

3. The control method according to claim 2, characterized in that: Determining the gear loss power according to the motor output torque, the motor speed, and the crankset output torque includes: determining a motor output power according to the motor output torque and the motor speed; determining a real-time gear transmission efficiency based on the motor speed, the crankset output torque, and a preset efficiency transmission function; wherein the preset efficiency transmission function is a relationship between the crankset output torque, the motor speed, and the real-time gear transmission efficiency, determined based on a current motor-gear-crankset transmission ratio; Determine the total gear power loss according to the real-time transmission efficiency of the gear and the output power of the motor; The gear loss power is determined based on the total gear loss power and the gear loss coefficient; wherein the gear loss coefficient represents the proportion of the gear loss to the total gear loss.

4. The control method according to claim 2, characterized in that: Determining the gear heat dissipation power according to the first temperature influencing factor and the control board temperature signal includes: Determining the inner cavity ambient temperature according to the control board temperature signal and the inner cavity temperature conversion coefficient; Determining a second temperature influence factor according to the first temperature influence factor and the inner cavity environment temperature; The gear heat dissipation power is determined according to the second temperature influencing factor and the heat dissipation coefficient; wherein the heat dissipation coefficient is the heat transfer coefficient from the corresponding gear to the inner cavity.

5. The control method according to claim 2, characterized in that: Determining the thermal conductivity of the control panel according to the first temperature influencing factor and the control panel temperature signal includes: Determining a third temperature influence factor according to the first temperature influence factor and the control board temperature signal; The heat conduction power of the control board is determined according to the third temperature influencing factor and the electrically controlled thermal conductivity coefficient.

6. The control method according to claim 2, characterized in that: Determining the predicted gear temperature according to the instantaneous internal energy of the gear and the first temperature influencing factor includes: Determining the gear temperature rise per unit time based on the instantaneous internal energy of the gear and the gear heat capacity; The predicted gear temperature is determined according to the gear temperature rise per unit time and the first temperature influencing factor.

7. The control method according to claim 1, characterized in that: Determining the allowable torque of the motor according to the predicted gear temperature includes: determining the allowable bending stress of the gear according to the predicted gear temperature; Determining the allowable torque of the gear according to the allowable bending stress of the gear; The motor allowable torque is determined according to the gear allowable torque and a preset reduction ratio.

8. A control device for a mid-mounted motor, characterized in that: A method for controlling a mid-mounted motor according to any one of claims 1 to 7, wherein the control device comprises: A signal acquisition module, configured to acquire a first temperature influencing factor, motor output torque, motor speed, crankset output torque, control board temperature signal, and a sampling period; a predicted temperature determination module, configured to determine a predicted gear temperature based on the first temperature influencing factor, the motor output torque, the motor speed, the crankset output torque, the control board temperature signal, and the sampling period; a motor torque determination module, configured to determine an allowable motor torque according to the gear predicted temperature when the gear predicted temperature is greater than a critical temperature threshold; The motor torque adjustment module is used to output a torque control signal to the motor according to the motor allowable torque, so as to control the motor to adjust the torque.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the control method according to any one of claims 1 to 7 is implemented.

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