Control method, device and equipment for mid-motor

Abstract

The invention discloses a control method, device and equipment for a mid-motor. The control method comprises the following steps: acquiring a first temperature influence factor, a motor output torque, a motor rotating speed, a crankset output torque, a control panel temperature signal and a sampling period; determining a gear prediction temperature according to the first temperature influence factor, the motor output torque, the motor rotating speed, the crankset output torque, the control panel temperature signal and the sampling period; when the gear prediction temperature is larger than the critical temperature threshold value, the allowable torque of the motor is determined according to the gear prediction temperature; and outputting a torque control signal to the motor according to the motor allowable torque to control the motor to adjust the torque. According to the technical scheme, it is guaranteed that operation of the gear is maintained within a safe range, noise caused by too high temperature of the gear is avoided, the operation problem of the middle motor caused by high temperature is avoided, the service life of the middle motor is prolonged, and the reliability of the middle motor is improved.

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 driving 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] The mainstream mid-mounted motors on the market currently do not have an integrated thermal management system or the corresponding thermal management system is imperfect. When the motor runs at high temperatures for a long time, the plastic gears have poor heat resistance due to their own material properties. Running at high temperatures for a long time will cause thermal expansion of the plastic gears, which will cause meshing noise when the plastic gears are driven. On the one hand, the noise will greatly affect the user's riding experience; on the other hand, the noise is generated by vibration. Long-term vibration will cause wear on the gear tooth surface of the transmission system, reduce meshing accuracy, and further aggravate wear, shortening the service life of each gear and causing safety hazards during riding.

[0004] Existing control methods tend to focus on temperature prediction and control of the motor in the mid-mounted motor, and do not consider the management and protection of the key component 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 gears may not operate normally at high temperatures due to a gearless thermal management system, and even the service life of the mid-mounted motor may be affected.

[0006] According to a first aspect of the present invention, a control method for a mid-mounted motor is provided, the mid-mounted motor comprising 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 according to the first temperature influencing factor, the motor output torque, the motor speed, the crankshaft output torque, the control board temperature signal and the sampling period;

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

[0011] A torque control signal is output to the motor according to the allowable torque of the motor 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 crankshaft output torque, the control board temperature signal and the sampling period includes:

[0013] Determine the gear power loss 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 according to 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 according to 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 toothed disc and the preset efficiency transmission function;

[0020] Determine the total gear power loss based on the gear real-time transmission efficiency and motor 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 according to the control board temperature signal and the inner cavity temperature conversion coefficient;

[0024] Determine a second temperature influence factor according to the first temperature influence factor and the inner cavity environment 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] Determine a third temperature influence factor according to the first temperature influence factor and the control board temperature signal;

[0028] The thermal conductivity of the control board is determined according to the third temperature influencing factor and the electrically controlled thermal conductivity.

[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 influence factor includes:

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

[0034] Determine 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, the predicted gear temperature is obtained and the 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 according to 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 comprises:

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

[0043] A predicted temperature determination module, used to determine the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the crank output torque, the control board temperature signal and the sampling period;

[0044] A motor torque determination module, used 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 allowable torque of the motor, so as 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, sprocket 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, 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 limitation 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 contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily 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 is a schematic diagram of a connection between a mid-mounted motor and a crankset provided according to an embodiment of the present invention;

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

[0053] Figure 4 is a flow chart of a first method for controlling a mid-mounted motor provided according to 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] Fig. 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] Fig.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] Fig.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] Fig.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] Fig.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] Fig.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] Fig.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] Fig.16 is a flow chart of a ninth method for controlling a mid-mounted motor provided according to an embodiment of the present invention;

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

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

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

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

[0070] Fig.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 scheme of the present invention, the technical scheme 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 described embodiments 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 creative work should fall within the scope of protection of the present invention.

[0072] It should be noted that the terms "first", "second", etc. in the specification 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 data 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 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 is a schematic diagram of a connection between a mid-mounted motor and a crankset according to an embodiment of the present invention. Figure 2 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 from a second perspective according to an embodiment of the present invention. 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 power-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, and the motor 11 is transmission-connected to the gear 12. The control board 13 can control the motor 11 to rotate, and then the motor 11 drives the gear 12 to rotate. 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 primary driven wheel 121 is connected to the motor 11 through the motor shaft 111, the secondary driving wheel 122 is coaxially connected to the primary driven wheel 121, the primary driven wheel 121 rotates to drive the secondary driving wheel 122, the secondary driven wheel 123 is connected to the secondary driving wheel 122, the secondary driving wheel 122 drives the secondary driven wheel 123 to rotate, the tertiary driving wheel 124 is coaxially connected to the secondary driven wheel 123, the secondary driven wheel 123 drives the tertiary driving wheel 124 to rotate, the tertiary driving wheel 124 is connected to the tertiary driven wheel 125, the tertiary driving wheel 124 drives the tertiary driven wheel 125 to rotate. The chainring 2 of the electric power-assisted bicycle is coaxially connected to the tertiary driven wheel 125 through the middle shaft 14, the tertiary driven wheel 125 drives the chainring 2 to rotate, thereby realizing the power assistance of 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 will cause the plastic gears 12 to expand thermally 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, in an embodiment of the present invention, a control method for the mid-mounted motor 1 is provided to limit the power assistance of the mid-mounted motor 1 based on the temperature of the gears 12 in the mid-mounted motor 1. Figure 4 is a flow chart of a first mid-mounted motor control method provided according to an embodiment of the present invention, combined with 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] Among them, the first temperature influencing factor may be the initial predicted temperature of the gear 12. Since the gear 12 is arranged in the inner cavity of the mid-mounted motor 1, when the mid-mounted motor 1 is started for the first time, the initial predicted temperature of the gear 12 may be the ambient temperature of the gear 12, that is, the temperature of the inner cavity of the mid-mounted motor 1. The temperature may be obtained using a temperature sensor arranged on the central axis 14. When the mid-mounted motor 1 is not started for the first time, the initial predicted temperature of the gear 12 may be the predicted temperature of the gear in the previous acquisition cycle. It is understandable that the gear 12 in the embodiment of the present invention may be any gear 12 in the mid-mounted 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 crank 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 disposed 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 tooth plate output torque, and the control board temperature signal. In order to ensure the accuracy of the calculation, the sampling periods of the first temperature influence factor, the motor output torque, the motor speed, the tooth plate output torque, and the control board temperature signal can be set to the same sampling period.

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

[0080] Among them, the gear power loss can be determined by the motor output torque, motor speed and tooth plate output torque; since the first temperature influence factor is the initial predicted temperature of the gear 12, and the control board temperature signal is the temperature of the control board 13, the influence of the control board temperature on the gear 12 and the influence of the temperature of the gear 12 on the heat dissipation of the inner cavity can be determined by the first temperature influence factor and the control board temperature signal, and the gear predicted temperature is determined according to the gear power loss, the influence of the temperature of the control board 13 on the gear 12 and the influence of the temperature of the gear 12 on the heat dissipation of the inner cavity. The gear predicted temperature is the gear predicted temperature in the current acquisition cycle.

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

[0082] Among them, the critical temperature threshold can be a temperature value that affects the normal operation of the gear 12 and the life of the mid-mounted motor 1. When the gear predicted temperature is greater than the critical temperature threshold, it means that the temperature of the gear 12 is too high and will affect the normal operation of the mid-mounted motor 1. The motor torque needs to be intervened to prevent the temperature of the gear 12 from continuing to rise. Therefore, the gear predicted temperature is used to determine the motor allowable torque. The motor allowable torque is the maximum torque that the motor 11 can output at the current gear predicted temperature.

[0083] S13, outputting a torque control signal to the motor according to the allowable torque of the motor 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, firstly, the first temperature influence factor, motor output torque, motor speed, tooth plate output torque and control board temperature signal under the sampling period are obtained, and the gear prediction temperature A℃ is determined according to the first temperature influence factor, motor output torque, motor speed, tooth plate output torque, control board temperature signal and sampling period, and it is judged whether the gear prediction temperature A℃ is greater than the critical temperature threshold value A0℃. When A℃>A0℃, the maximum output torque of the motor 11 allowed at this temperature is determined according to the gear prediction temperature A℃, and the current motor output torque is adjusted according to the motor allowable torque, so that the temperature of the gear 12 is reduced, the normal operation of the gear 12 is ensured, and the service life of the mid-mounted motor 1 is extended. It can be understood that the gear prediction temperature in the technical solution of the embodiment of the present invention is a real-time prediction. When A℃≤A0℃, the first temperature influence factor, motor output torque, motor speed, tooth plate output torque and control board temperature signal are continuously collected, and the torque of the motor 11 is not controlled.

[0086] For example, since the motor 11 is in transmission connection with the gear 12, and the gear 12 is in transmission connection with the chainring 2, the adjustment result of the motor 11 is finally directly reflected in the output torque of the chainring. Under the operating condition of the chainring at 80rpm and 100Nm, two cases with and without the control method of the embodiment of the present invention were tested and data were 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 motor is started at the working condition of 80rpm and 100Nm of the chainring, the initial maximum allowable torque of the motor is 2.6Nm. 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 whole 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 a 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 the control method of the embodiment of the invention is introduced, the steady-state torque drops from 60 Nm to 55 Nm, thereby 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, sprocket 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, 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 limit requirements.

[0096] Based on the above embodiments, Fig. 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 Fig. 9 As shown, the control method includes:

[0097] S20, 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.

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

[0099] Among them, the motor output power can be determined according to the motor output torque and the motor speed. Theoretically, the motor output power needs to be fully transmitted to the gear 12. Part of the gear power is transmitted to the toothed disc 2, and part of it is lost. The lost part is converted into internal energy and dissipated. Therefore, the gear loss power can be determined according to the motor output torque, the motor speed and the toothed disc output torque. The gear loss power is related to the gear internal energy, that is, it is related to the temperature of the 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] Among them, since the first temperature influencing factor is the initial predicted temperature of the gear, the initial predicted temperature of the gear is affected by the gear 12 itself. Since the gear 12 also dissipates heat during operation and transfers the heat to the inner cavity; the control board 13 also dissipates heat during operation, and the heat dissipation of the control board 13 also affects the temperature of the gear 12, 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 board heat conduction power and the sampling period.

[0103] Among them, since the temperature of the gear 12 is jointly 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. loss , Gear heat dissipation power P dispat , control board thermal power P conduct , sampling period x and instantaneous internal energy of the gear 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 instantaneous internal energy of the gear affects the heating temperature of the gear 12 in the sampling period, and the first temperature influence factor is the initial predicted temperature of the gear, the predicted temperature of the gear can be determined according to the instantaneous internal energy of the gear and the first temperature influence factor.

[0106] S25. When the predicted gear temperature is greater than a critical temperature threshold, determine the allowable torque of the motor 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 according to the motor output torque, motor speed and chainring output torque, determines the gear heat dissipation power and the control board thermal conductivity power according to the first temperature influencing factor and the control board temperature signal, determines the gear instantaneous internal energy according to the gear loss power, gear heat dissipation power, control board thermal conductivity power and sampling period, that is, the heating temperature of the gear within the sampling period, and determines the gear predicted temperature according to the gear instantaneous internal energy and the first temperature influencing factor, thereby realizing the prediction of the gear temperature.

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

[0110] S30, 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.

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

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

[0113] S32, determining 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 may be a relationship between the output torque of the toothed disc, the motor speed and the real-time transmission efficiency of the gear, determined based on the current transmission ratio of the motor-gear-toothed disc. The real-time transmission efficiency of the gear η=f(n,Tz) can be determined by the real-time collected motor speed n and toothed disc 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 totaloss Between 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 thermal conductivity 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 board 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 allowable torque of the motor according to the predicted gear temperature.

[0123] S39, outputting 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 accurately predict the temperature of the corresponding gear subsequently.

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

[0126] S40, 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.

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

[0128] S42, determining 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 according to 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 influence of the control board temperature on the inner cavity temperature. Control board temperature signal Temp NTC , the inner cavity temperature conversion coefficient a and the inner cavity ambient temperature T inner Between inner =a*Temp NTC .

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

[0131] 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 and the second temperature influence factor K2 satisfy 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, 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. In this way, the heat transfer power of the gear to the inner cavity is determined.

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

[0135] S46. 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.

[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 allowable torque of the motor according to the predicted gear temperature.

[0138] S49, outputting a torque control signal to the motor according to the allowable torque of the motor 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 heating temperature of the gear 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, Fig.12 is a flow chart of a fifth method for controlling a mid-mounted motor according to an embodiment of the present invention. Fig.12 As shown, the control method includes:

[0141] S50, 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.

[0142] S51, determining 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 according to 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 satisfy K3=Temp NTC -K1.

[0145] S54. Determine the thermal conductivity power of the control board 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. The third temperature influence factor K3, the electric control thermal conductivity 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 board 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 allowable torque of the motor 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 accurately predict the temperature of the corresponding gear in the subsequent process.

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

[0153] S60, 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.

[0154] S61, determining the gear loss power 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 board 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 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 cycle, 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 pred =K1+Δt.

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

[0162] S67: Output a torque control signal to the motor according to the allowable torque of the motor 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 instantaneous internal energy of the gear, the 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, Fig.14 is a flow chart of a seventh method for controlling a mid-mounted motor according to an embodiment of the present invention. Fig.14 As shown, the control method includes:

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

[0166] Among them, since the thermal influence of the gear mainly comes from the inner cavity temperature when the central motor is started for the first time, the inner cavity temperature signal is obtained at this time. The temperature sensor corresponding to the inner cavity temperature signal can be set 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, obtaining the motor output torque, motor speed, sprocket output torque, control board temperature signal and sampling period.

[0170] S73, determining the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the sprocket 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 allowable torque of the motor 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, Fig.15 is a flow chart of an eighth method for controlling a mid-mounted motor according to an embodiment of the present invention. Fig.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 not only affected 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 predicted temperature of the gear in the previous acquisition cycle, and the predicted gear temperature is used as the first temperature influencing factor.

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

[0177] S82, determining the predicted gear temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the sprocket 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 allowable torque of the motor according to the predicted gear temperature.

[0179] S84, outputting a torque control signal to the motor according to the allowable torque of the motor to control the motor to adjust the torque.

[0180] It can be understood that the sources of the first temperature influence factor of the embodiment of the present invention are divided into two situations. The first is when the central motor is started for the first time. At this time, the first temperature influence factor is only related to the inner cavity temperature signal, so the first temperature influence factor is determined according to the inner cavity temperature signal and the temperature influence function; the second is when the central motor is not started for the first time. At this time, the first temperature influence factor is the gear predicted temperature of the previous acquisition cycle. The technical solution of the embodiment of the present invention fully considers the thermal influence inside the central motor and improves the accuracy of the gear predicted temperature.

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

[0182] S90, 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.

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

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

[0185] S93. Determine the allowable bending stress of the gear according to the predicted temperature of the gear.

[0186] in, Fig.17 is a graph showing the relationship between temperature and gear stress and strain according to an embodiment of the present invention. Fig.17 As shown in Figure 2, the stress and strain of gears at different temperatures are different. Especially when the gear is made of plastic, the stress and strain at different temperatures can be expressed as Fig.17 As shown. Similarly, Fig.18 is a relationship diagram between temperature and gear elastic modulus provided according to an embodiment of the present invention, such as Fig.18 As shown in the figure, the elastic modulus of the gear is different at different temperatures. The allowable bending stress of the gear is determined by combining the gear stress change and the elastic modulus, which characterizes the limit bending stress of the gear. If it is greater than the allowable bending stress of the gear, the gear reliability will decrease and there will be safety hazards. Therefore, by determining the allowable bending stress of the gear according to the predicted temperature of the gear, the maximum bending stress that the gear can withstand at this temperature can be determined.

[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 according to 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 the temperature, and then 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 can be Tz = -1.1129*T pred +154.77. Fig.19is a relationship diagram between the predicted gear temperature and the crankshaft output torque provided according to an embodiment of the present invention, such as Fig.19 As shown, based on this relationship, a relationship diagram between the gear predicted temperature and the sprocket output torque 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 the 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 excessive gear temperature, and avoiding operation problems of the mid-mounted motor 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, Fig. 20 is a connection diagram of a control device for a mid-mounted motor provided according to an embodiment of the present invention, such as Fig. 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 acquire the first temperature influencing factor, the motor output torque, the motor speed, the crank 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 crankshaft output torque, the control board temperature signal and the sampling period.

[0195] The motor torque determination module 300 is used 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 used to output a torque control signal to the motor according to the allowable torque of the motor, so as to control the motor to adjust the torque.

[0197] Specifically, the signal acquisition module 100 is first used to acquire the first temperature influencing factor, the motor output torque, the motor speed, the toothed disc output torque, the control board temperature signal and the sampling period. The predicted temperature determination module 200 is then used to determine the gear predicted temperature according to the first temperature influencing factor, the motor output torque, the motor speed, the toothed disc output torque, the control board temperature signal and the sampling period. When the gear predicted temperature is greater than the critical temperature threshold, the motor torque determination module 300 is then used to determine the motor allowable torque according to the gear predicted temperature. The motor torque adjustment module 400 is then used to output a torque control signal to the motor according to the motor allowable torque to control the motor to adjust the 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 excessive 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, Fig.21 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, such as Fig.21 As shown, it includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, a control method for the central motor is implemented.

[0200] Among them, electronic devices are 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 devices can also represent various forms of mobile devices, such as personal digital processing, 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 merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0201] like Fig.21 As shown, the electronic device 50 includes at least one processor 51, and a memory connected to the at least one processor 51 in communication, such as a read-only memory (ROM) 52, a random access memory (RAM) 53, etc., wherein the memory stores a computer program that can be executed by at least one processor, and 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 to the random access memory (RAM) 53. In the RAM 53, various programs and data required for the operation of the electronic device 50 can also be stored. The processor 51, the ROM 52, and the 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] A number of 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 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 through a computer network such as the Internet and / or various telecommunication networks.

[0203] The processor 51 may be a variety of general and / or dedicated processing components 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 dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 51 executes the various methods and processes described above, such as a control method applied to a mid-mounted motor.

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

[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 execute 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 Fig.21 As shown, it is tangibly contained in a computer-readable storage medium, such as a storage unit 58. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 50 via the ROM 52 and / or the communication unit 59. When the computer program is loaded into the RAM 53 and executed by the processor 51, one or more steps of the control method applied to the mid-mounted motor described above can be performed. Alternatively, in other embodiments, the processor 51 can be configured to execute the control method applied to the mid-mounted motor in any other appropriate manner (for example, by means of firmware).

[0206] Various implementations of the systems and techniques described above 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), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including 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, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0208] In the context of an embodiment of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, device, or equipment. A computer-readable storage medium may 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 may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may 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 may 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 a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0210] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0211] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling a mid-mounted motor, characterized in that: The central motor includes a motor, a gear and a control board; The control method comprises: 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; 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; When the gear predicted temperature is greater than a critical temperature threshold, determining the motor allowable torque according to the gear predicted temperature; A torque control signal is output to the motor according to the motor allowable torque, so as to control the motor to adjust the torque.

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: Determine the gear loss power according to the motor output torque, the motor speed and the crank output torque; 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; 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 crankshaft output torque includes: Determining the motor output power according to the motor output torque and the motor speed; Determining the real-time transmission efficiency of the gear according to the motor speed, the output torque of the crankset and a preset efficiency transmission function; 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 according to the total gear loss power and the gear loss coefficient.

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: Determine the inner cavity ambient temperature according to the control board temperature signal and the inner cavity temperature conversion coefficient; Determine 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.

5. The control method according to claim 2, characterized in that: Determining the thermal power of the control panel according to the first temperature influencing factor and the control panel temperature signal includes: Determine a third temperature influence factor according to the first temperature influence factor and the control board temperature signal; The thermal conductivity 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: Determine the gear temperature rise per unit time according to 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: Get the first temperature impact factor, including: When the mid-mounted motor is started for the first time, obtaining an inner cavity temperature signal; Determine a first temperature influence factor according to the inner cavity temperature signal and the temperature influence function; Alternatively, obtaining the first temperature influencing factor includes: When the mid-mounted motor is not started for the first time, the predicted gear temperature is obtained and a first temperature influencing factor is determined according to the predicted gear temperature.

8. 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 temperature of the gear; 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.

9. A control device for a mid-mounted motor, characterized in that: Used to execute the control method of the mid-mounted motor according to any one of claims 1 to 8, the control device of the mid-mounted motor comprises: A signal acquisition module, used to acquire a first temperature influencing factor, a motor output torque, a motor speed, a crank output torque, a control board temperature signal and a sampling period; A predicted temperature determination module, used for 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; 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; 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.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the control method as described in any one of claims 1 to 8 is implemented.

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