Power assisting system and power assisting method of electric bicycle

Abstract

The invention provides a power assisting system of an electric bicycle. The power assisting system comprises a torque sensor, a power assisting motor and a controller. The torque sensor is arranged at the power input end of the bicycle and used for dynamically detecting the torque value of the power input end. The power-assisted motor is used for assisting power; the controller is used for receiving the torque value of the torque sensor, calculating the output power value of a person, obtaining the power value needing to be output by the motor after calculation and outputting corresponding current to the power-assisted motor, and the motor outputs corresponding power and torque. And the power is transmitted to the power-assisted motor for power assistance. According to the power assisting system of the electric bicycle, invalid power assisting can be achieved, and the problem that a traditional power assisting bicycle is missed in stepping or suddenly heavy is solved; corresponding torque is compensated when needed, and invalid energy consumption is reduced; the electric bicycle is suitable for complex road conditions, the riding efficiency under the scenes of climbing, upwind and the like is improved, a rider can keep basically the same power output, the requirement for treading force can be met, and the riding experience is good.

Description

Technical Field

[0001] The invention relates to an electric bicycle, and in particular to a power-assisting system and a power-assisting method for an electric bicycle. Background Art

[0002] In traditional cycling, whether it is a road bike or a city bike, the comfortable cadence is usually between 80 and 92 revolutions per minute. For European customers, this cadence range may be slightly lower; however, during cycling, whether on a flat road, uphill or downhill, cadence fluctuations are often difficult to avoid. Traditional bicycles adjust the cadence by manual speed change, but this method has many inconveniences:

[0003] 1. Complex operation: Road bikes are usually equipped with 24 gears (2 front gears × 12 rear gears). Manually switching gears is not only troublesome, but may also affect the riding experience due to unfamiliarity with the operation.

[0004] 2. Slow response: Most people have slow feedback when judging the riding status and are unable to adjust the gear in time, resulting in a sense of frustration during riding.

[0005] In order to solve the above problems, an electric power-assisting device has appeared in the prior art, which sets a transmission in the power-assisting motor, that is, adopts the form of a dual-speed power-assisting motor or a three-speed. The dual-speed power-assisting motors currently on the market (such as the products of 8fang Electric and Anida) increase the torque by built-in two-speed or three-speed transmissions. However, this design has obvious defects: there is an obvious sense of frustration during the speed change process, which affects the riding experience; the complexity of the mechanical structure is increased, resulting in higher costs, larger size, heavier weight, 250W difference is about 1 kilogram and it is easier to increase the probability of after-sales service.

[0006] Therefore, it is necessary to develop a power assist system that can effectively solve the above problems. Our company originally envisioned three solutions:

[0007] 1. Use pedal frequency or speed sensing, and the four-variable linear equation form can be found in our digital torque patent;

[0008] 2. With torque sensing, the pedaling frequency is not correct, there is a sense of frustration, and manual shifting is required;

[0009] 3. Built-in gyroscope in the motor;

[0010] Later, we found that the speed sensor was not accurate enough and the built-in gyroscope was expensive. After comprehensive comparison, we chose the torque solution. Compared with traditional speed sensors, torque sensors are more sensitive. They can accurately sense the change in the force of your foot on the crank. Even if the pedaling frequency only drops by 5 revolutions, the system can immediately feedback and adjust the motor output to ensure that there is no frustration during riding.

[0011] Meanwhile, current electric assist bicycles include speed assist and torque assist:

[0012] The so-called speed assist adjusts the current input to the motor and the output torque according to the pedaling speed to provide assistance. The so-called torque assist adjusts the current input to the motor and the output torque according to the torque value when stepping on the pedal.

[0013] The disadvantage of speed assist is that the faster you pedal, the higher the current output, and the faster the motor rotates. So when the speed is high, it will cause a feeling of pedaling into thin air, that is, when you step on the pedal, there is nothing, and the rotation frequency of the motor is faster than the pedaling frequency.

[0014] For the torque sensor, there is a phenomenon that the greater the foot force, the greater the auxiliary current, and the faster the motor rotates. There is also a relationship between the rotation speed and the pedaling frequency.

[0015] Later, an evolution occurred where both a speed sensor and a torque sensor were equipped with a gear shift. Different gears are used to determine different current ratios to the input of the pedal. To a certain extent, it solves the problem of pedaling into thin air.

[0016] However, there is still a problem of pedaling into thin air. In addition, after adding a gear shift, manual operation and control are required, so manual gear shifting is needed when traveling to a certain extent, which reduces the riding experience.

[0017] Both without a gear shift and with a gear shift have a common problem, that is, in the same gear, the current ratio is fixed. It cannot instantaneously or immediately match the torque of the pedal, which will increase power consumption. That is, the ratio of the pedal to the torque output of the motor does not form a relatively fixed ratio. When the speed is faster and the torque is greater, the motor quickly catching up will cause a sense of jerk and increased power consumption. The increase in motor torque is greater than the increase in motor torque required by the rider, that is, it increases power consumption.

[0018] In addition, a speed or torque sensor cannot recognize the requirements for flat road starts and starts on a slope, that is, the requirements for starting on a sloped road surface.

[0019] Because the torque required for a flat road start is much lower than the torque required for starting on a slope. Summary of the Invention

[0020] The technical problem to be solved by the present invention is to provide an electric bicycle assist system and an assist method that can adjust the assistance in real time through dynamic torque sensing technology, so that the riding torque is always stable at the initial force value set by the user, to maintain the expected pedaling feel of the rider, and thus improve the riding experience.

[0021] The present invention provides an electric bicycle assist system, which includes:

[0022] A torque sensor is arranged at the power input end of the bicycle and is used for dynamically detecting the torque value at the power input end;

[0023] An assisting motor is connected to the driving wheel of the bicycle and is used for assisting the driving wheel;

[0024] A controller is electrically connected to the torque sensor and the assisting motor respectively, and is used for calculating the assisting value after receiving the torque value of the torque sensor and transmitting it to the assisting motor for assistance.

[0025] It further includes a gyroscope for detecting the riding gradient and then determining the starting torque of the assisting motor by the controller itself.

[0026] Furthermore, the power input end is the bottom bracket.

[0027] Furthermore, the assisting motor is a hub motor or a mid-drive motor.

[0028] Furthermore, the output torque of the assisting motor is 0 - 55 N·m.

[0029] Furthermore, the assisting motor includes:

[0030] A main shaft for connecting to the vehicle frame;

[0031] A hub housing, serving as the output end and used for connecting to the wheel, and the hub housing is rotatably mounted on the main shaft;

[0032] A stator, located inside the hub housing and fixed on the main shaft;

[0033] A rotor, located inside the hub housing and capable of rotating around the stator;

[0034] A planetary reduction assembly is arranged between the rotor and the hub housing and is used for transmitting the power of the rotor to the hub housing and driving the hub housing to rotate;

[0035] The iron core of the stator and / or the rotor is made of amorphous material.

[0036] Furthermore, the proportion of the 80% efficiency platform of the hub motor is greater than 20%.

[0037] Furthermore, the operating frequencies of the torque sensor and the assisting motor are 50 - 500 Hz.

[0038] Furthermore, it further includes a manual control end, and the manual control end is used for controlling the opening, closing of the assisting system, and the selection or setting of the ideal torque threshold.

[0039] Meanwhile, the present invention also provides an assisting method for an electric bicycle assisting system, which includes the following steps:

[0040] S1. Select or set an ideal torque threshold T1, where the ideal torque threshold T1 is the torque value under the desired pedaling feel.

[0041] S2. The torque sensor detects the torque value T2 at the power input end and compares it with the ideal torque value T1 through the controller.

[0042] When T2 ≤ T1, it is determined that no assistance is required, and the assistance motor does not provide assistance.

[0043] When T2 > T1, it is determined that assistance is required, calculate the difference between the two and obtain the required assistance torque T3:

[0044] T3 = T2 - T1;

[0045] S3. The controller calculates the current of the assistance motor at the assistance value T3 and transmits it to the assistance motor, so that the output torque of the assistance motor is T3, realizing the compensation of the torque difference at the power input end, and further keeping the torque value at the power input end at the ideal torque threshold T1.

[0046] Further, there is a step S12 between steps S1 and S2, and this step S12 includes the following steps:

[0047] Detect the current riding angle through the gyroscope and automatically select or match the preset starting gear according to the detected angle to achieve starting on different slopes.

[0048] Further, the starting gear is used to achieve starting on different slopes, and it has 1 - N gears. The starting torque corresponding to each gear is:

[0049]

[0050] where T 启 is the starting torque range of the assistance motor, n is the currently selected gear of the assistance motor, T max is the maximum output torque of the assistance motor, and N is the number of gears;

[0051] After adapting the starting gear, use the maximum torque within this gear as the starting torque.

[0052] Further, steps S2 - S3 constitute an assistance cycle, and the frequency of the assistance cycle is 50 - 500 Hz.

[0053] The electric bicycle assistance system of the present invention adopts a continuously variable transmission system and has the following advantages:

[0054] There is no sense of jerk. Through the precise feedback of the torque sensor, the system can adjust the power output in real time to ensure a smooth and silky riding process.

[0055] It has a simple structure without a complex mechanical variable speed structure, reducing weight, cost and failure rate.

[0056] Efficiently cover various road conditions. The efficient power output of the motor can adapt to various urban road conditions. No matter how the slope changes, a stable riding experience can be maintained.

[0057] Improve riding efficiency. By maintaining a comfortable pedaling frequency range, the system can significantly improve riding efficiency, making the rider's ride more relaxed.

[0058] Enhance comfort. The continuously variable transmission system can adjust the power output in real time according to road conditions, ensuring no jerks during the riding process and bringing an ultimate comfortable experience.

[0059] Adapt to various scenarios. Whether on flat roads, uphill or downhill, the system can maintain stable performance and adapt to various riding scenarios.

[0060] Reduce the learning cost. There is no need to manually switch gears. Even novice riders can easily get started and enjoy a professional-level riding experience.

[0061] At the same time, a self-developed amorphous motor is adopted, which can provide a torque of more than 52 N·m when going uphill, and the highest efficiency reaches 86%. Its efficiency platform is broadened by 120%. In most usage scenarios, the motor can maintain efficient operation. This efficient power output not only improves the riding comfort but also achieves a true continuously variable transmission effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic structural diagram of the electric bicycle assistance system of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0064] Refer to Figure 1 , the present invention provides an electric bicycle assistance system, which includes a torque sensor, an assistance motor and a controller.

[0065] Among them, the torque sensor is set at the power input end of the bicycle and is used to dynamically (in real time) detect the torque value at the power input end. In this application, the power input end is the bottom bracket, that is, the main shaft connected to the pedal; the bottom bracket is the core hub for the transmission of the rider's pedaling force, directly bearing the torque of the crank and the chain. Installing the torque sensor here can directly measure the torsional deformation of the crankshaft, avoiding measurement errors caused by mechanical transmission losses (such as chain friction and gear clearance) at positions such as the pedal or the rear fork. It can ensure that the detected torque value truly reflects the force actually applied by the rider and provides a high-precision input for subsequent motor compensation. At the same time, the bottom bracket usually adopts a sealed bearing structure and is rigidly connected to the frame, being less affected by external vibrations (such as road bumps) or temperature changes, with low sensor signal noise, reducing the controller's dependence on filtering algorithms; it is not easily subject to measurement drift due to mechanical wear during long-term use, and the system has higher reliability.

[0066] The assist motor is connected to the drive wheel of the bicycle and is used to assist the drive wheel. The drive wheel is the rear wheel of the bicycle; the assist motor is a mid-drive motor or a hub motor. Preferably, a hub motor is used and is directly set on the rear wheel of the bicycle.

[0067] In this application, a gyroscope is also included, which is used to detect the riding angle and then determine the starting torque of the assist motor by itself through the controller.

[0068] The above gyroscope is used to detect the current slope of the bicycle. At the same time, a combination of a gyroscope and an accelerometer can also be used for angle measurement, or angle (slope) detection can be performed through other angle sensors.

[0069] In this application, installing a gyroscope on the bicycle enables the whole vehicle to have the ability to recognize the slope. Therefore, when starting on a corresponding flat road or different slope roads, the gyroscope will perform slope detection, that is, form a slope parameter. This parameter will correspondingly call the maximum torque required when starting at different angle slopes, and this torque is the best matching parameter equal to the torque output by the person and the motor.

[0070] Therefore, when starting at different slopes, the controller outputs different signals to make the motor provide different torques at different slopes, so that the rider's pedaling force always remains within a self-set pedaling range. The riding start is relatively easy, and all supplementary torques reach the use target value instantly by the motor. It avoids the phenomenon of power lag or sudden forward rush during the starting process at different slopes and greatly improves the use experience.

[0071] Specifically, multiple gears are prefabricated in the control system, and each gear has its own torque range. In this application, it has N gears, and the starting torque corresponding to each gear is:

[0072]

[0073] Among them, T 启 is the starting torque range of the assist motor, n is the selected gear of the current slope of the assist motor, and T max is the maximum output torque of the assist motor, and N is the number of gears; after adapting the corresponding starting gear according to the angle, the maximum torque within that gear is used as the starting torque to reduce the calculation time and improve the response speed.

[0074] The following gives a distance description of the starting gears:

[0075] Taking the maximum torque of the assist motor as 55 N·m as an example, assuming N is 10, that is, there are gears 1 - 10, and taking the inclination angle of 1° as the division boundary, the corresponding torque ranges of each gear are:

[0076] Gear 1: (0 - 5.5], that is, greater than 0 and less than or equal to 5.5 N·m; its adapted slope has an angle greater than or equal to 0 degrees and less than 1 degree.

[0077] Gear 2: (5.5 - 11], that is, greater than 5.5 and less than or equal to 11 N·m; its adapted slope has an angle greater than or equal to 1 degree and less than 2 degrees.

[0078] Gear 3: (11 - 16.5], that is, greater than 11 and less than or equal to 16.5 N·m; its adapted slope has an angle greater than or equal to 2 degrees and less than 3 degrees.

[0079] Gear 4: (16.5 - 22], that is, greater than 16.5 and less than or equal to 22 N·m; its adapted slope has an angle greater than or equal to 3 degrees and less than 4 degrees.

[0080] Gear 5: (22 - 27.5], that is, greater than 22 and less than or equal to 27.5 N·m; its adapted slope has an angle greater than or equal to 4 degrees and less than 5 degrees.

[0081] Gear 6: (27.5 - 33], that is, greater than 27.5 and less than or equal to 33 N·m; its adapted slope has an angle greater than or equal to 5 degrees and less than 6 degrees.

[0082] Gear 7: (33 - 38.5], that is, greater than 33 and less than or equal to 38.5 N·m; its adapted slope has an angle greater than or equal to 6 degrees and less than 7 degrees.

[0083] Gear 8: (38.5 - 44], that is, greater than 38.5 and less than or equal to 44 N·m; its adapted slope has an angle greater than or equal to 7 degrees and less than 8 degrees.

[0084] Gear 9: (44 - 49.5], that is, greater than 44 and less than or equal to 49.5 N·m; its adapted slope has an angle greater than or equal to 8 degrees and less than 9 degrees.

[0085] 10th gear: (49.5 - 55], that is, greater than 49.5 and less than or equal to 55 N·m; its adapted angle is greater than or equal to 9 degrees and less than 10 degrees, preferably, all slopes greater than or equal to 9 degrees.

[0086] In this application, according to different riding purposes and scenarios, different assist motors (powers) can be set. The assist motors can include the following types:

[0087] 1. Power 250w, output torque is 0 - 55 N·m, which is applicable to light bicycles and is suitable for usage scenarios with relatively low riding slopes and load, such as road bikes and city commuter bikes, mainly used for city riding, commuting, and leisure riding.

[0088] 2. Power 350w, output torque 0 - 75 N·m, which is applicable to light mountain bikes and is suitable for usage scenarios with a certain riding slope or a certain load requirement, such as all - terrain vehicles and touring bikes.

[0089] 3. Power 500w, output torque 100 N·m, applicable to usage scenarios with a relatively large riding slope or a relatively large load requirement, such as all - terrain vehicles, touring bikes, etc.

[0090] 4. Power 750w, output torque 120 N·m, applicable to usage scenarios with a relatively large riding slope and heavy load, such as all - terrain vehicles, climbing bikes, heavy - duty mountain bikes, etc.

[0091] That is, different motor powers can be selected according to different usage requirements, so as to minimize the volume on the premise of meeting the usage requirements, reduce the overall installation space and the overall weight.

[0092] According to different usage scenarios, the number of starting gears can be 5 - 20, preferably 8 - 15. The greater the slope span and the stronger the load - carrying capacity of the usage scenario, the more the number of gears. Thus, it can quickly locate the required starting torque at an appropriate slope and load, greatly reduce the calculation time, improve the response speed, and avoid the problem of power lag.

[0093] The hub motor in this application includes a main shaft, a hub housing, a stator, a rotor, and a planetary reduction assembly. Among them, the iron cores of the stator and / or the rotor are made of amorphous materials.

[0094] The output speed of the assist motor in this application, that is, the output speed of the hub housing, is 180 RPM - 420 RPM. The transmission ratio of the planetary reduction assembly is greater than or equal to 9 and less than or equal to 12, preferably 9.5 - 10, and the optimal transmission ratio is 115 / 12 ≈ 9.58, and its highest output efficiency is greater than or equal to 85%; and the proportion of the 80% efficiency platform of the assist motor:

[0095]

[0096] Among them, N1 is the torque range where the motor efficiency is greater than or equal to 80%, N2 is the entire torque range of the motor, that is, the range from 0 to the stall torque (maximum torque), and the torque range of the 80% efficiency platform, that is, the span from the starting point to the end point of the torque when the efficiency is greater than 80%. The larger the span, the higher the efficiency, which enables the motor to maintain a high working efficiency under different working conditions. In this application, the efficiency ratio above 80% is More than 30%, preferably more than 36% , that is, from the lowest speed (0 RPM) to the highest speed, 30% (36%) and above of the output efficiency is greater than 80%.

[0097] The output torque of the assist motor in this application is 0 - 55 N·m, that is, the maximum is 55 N·M. The large torque provides guarantee for climbing assistance, is suitable for mountain road riding, and has a wide range of application scenarios. In this application, the input voltage of the assist motor is 36V.

[0098] Compared with traditional motors, this application uses the amorphous assist motor independently developed by our company. The iron core is made of amorphous material, and the transmission ratio is optimized. While improving the motor efficiency, it also broadens the efficiency platform range, enabling the motor to maintain a high working efficiency under different working conditions. It not only reduces energy consumption and brings a longer battery life, but also improves the stability and reliability of the motor in the full working condition range; at the same time, on the premise of meeting the design requirements, it greatly reduces the product volume, reduces the installation space, is conducive to the installation and layout on the vehicle, reduces the production cost, and enhances the market competitiveness. This enables the motor to show excellent performance in diverse application scenarios, meeting the urgent needs of modern transportation for high efficiency, low energy consumption, and low carbon; in addition, the use of amorphous material also brings good thermal stability and corrosion resistance, with small iron core loss, further extending the service life of the motor, reducing the maintenance cost, and bringing a better experience to users; it provides a basic guarantee for the stepless assistance of this application.

[0099] The controller is electrically connected to the torque sensor and the assist motor respectively. After receiving the torque value of the torque sensor, it calculates the assist value and transmits it to the assist motor for assistance.

[0100] In this application, DTSS (Dynamic Torque Sensing System), that is, dynamic torque sensing technology, is used for electric assist bicycles (E-bikes) and other electric assist kits. Different from traditional cadence sensing or fixed torque sensing, DTSS can adjust the motor output in real time according to the rider's pedaling force, riding state, and road condition changes, providing a more natural, smooth, and efficient riding experience and dynamically adjusting the torque output.

[0101] Compared with traditional fixed-ratio assistance, DTSS can calculate the optimal assistance power in real time according to the force exerted by the user, making cycling more intuitive. With instant response, cycling becomes smoother. Traditional pedal frequency sensing technology may have delays, resulting in jerks during startup or drag during stop, affecting the user experience and comfort. In contrast, DTSS can achieve millisecond-level response, providing a smoother power output, improving energy efficiency, and extending the battery life. By precisely controlling the output of the motor power, DTSS reduces unnecessary power consumption, improves battery usage efficiency, and extends the battery life. It can adapt to various terrains and cycling styles. Whether it is urban commuting, mountain biking, or long-distance travel, DTSS can intelligently adjust the assistance intensity to ensure the best power output.

[0102] The working frequency of the torque sensor and the assist motor in this application is 50 - 500 Hz, that is, the working cycle is 2 - 20 milliseconds. It has a fast response, can provide a smoother power output, avoid the problems of sudden startup and lag during stop caused by slow response, improve cycling comfort, and at the same time improve energy efficiency and extend the battery life.

[0103] Meanwhile, this application also includes a manual control terminal, which is set on the handlebar and is used to control the opening, closing of the assistance system, and the selection or setting of the ideal torque threshold. The ideal torque threshold is the force under the desired pedaling feel. Different cyclists have different desired pedal feels and can preset different gear , each gear has a preset ideal torque threshold. During cycling, select the gear suitable for oneself, which is convenient to use. Or the ideal torque threshold can be directly set. When the preset does not meet the needs of the cyclist, the torque threshold can be set by oneself, with high flexibility.

[0104] Meanwhile, the present invention also provides an assistance method for an electric bicycle assistance system, which includes the following steps:

[0105] S1. Select or set the ideal torque threshold T1. The ideal torque threshold T1 is the torque value of the pedal under the desired pedaling feel.

[0106] S2. The torque sensor detects the torque value T2 of the power input end and compares it with the ideal torque value T1 through the controller.

[0107] When T2 ≤ T1, that is, the torque value of the pedal at the power input end is less than or equal to the ideal torque value, it is judged that no assistance is needed, and the assist motor does not provide assistance.

[0108] When T2 > T1, that is, the torque value of the pedal at the power input end is greater than the ideal torque value, it is judged that assistance is needed, calculate the difference between the two and obtain the required assistance torque T3:

[0109] T3 = T2 - T1, and this torque value is the force applied by the foot that is greater than the ideal torque value.

[0110] S3. Calculate the current of the assist motor at the assist value T3 through the controller, and transmit it to the assist motor, so that the output torque of the assist motor is T3, realizing the compensation of the torque difference at the power input end, and further keeping the torque value at the power input end within the ideal torque threshold T1; that is, the difference in torque greater than the ideal torque applied by the rider is synchronously compensated by the assist motor, so that the force applied by the rider is maintained at the ideal torque value; when decelerating and stopping, no force is applied and no assistance is provided, that is, T2 decreases to 0, realizing coasting or stopping; the above steps S2 - S3 constitute an assist cycle, and the frequency of the assist cycle is 50 - 500 Hz, that is, the working cycle of the assist system in this application is 2 - 20 milliseconds, realizing fast response, ensuring smooth assistance, avoiding abrupt and lag phenomena, and improving the riding experience.

[0111] Taking one cycle as an example; the comfort of the rider's pedal output is the best when it is at T1, so the ideal torque value is set to T1.

[0112] In the starting stage, the pedal force increases from 0. When the ideal torque T1 is not reached, the assist motor does not provide assistance.

[0113] When continuing to accelerate or climb a slope, when the pedal force increases and equals the ideal torque T1, the force actually applied by the rider begins to exceed the ideal torque. At this time, the motor starts to provide assistance.

[0114] Assuming that without the assistance of the motor, that is, when completely applied by the rider's pedal, the torque value T2 of the rider on the power input end is the total torque required during riding, while the ideal torque of the rider is T1, and the two form a difference, that is, T2 minus T1. The assist motor can only keep the rider's output at the ideal torque and keep the total torque during riding or climbing unchanged by synchronously compensating this difference torque, so that the rider always has an ideal riding feel and riding state.

[0115] The following is an example for illustration:

[0116] Taking one cycle as an example; the comfort of the rider's pedal output is the best when it is at 10 N·m, so the ideal torque value T1 is set to 10 N·m.

[0117] In the starting stage, the pedal force increases from 0. When the ideal torque of 10 N·m is not reached, the assist motor does not provide assistance.

[0118] When continuing to accelerate or climb a slope, when the pedal force increases and is greater than the ideal torque of 10 N·m, the force actually applied by the rider begins to exceed the ideal torque. At this time, the motor starts to provide assistance.

[0119] For example, when the force applied by the rider is 12 N·m, the difference between it and the ideal torque is 2 N·m (12 - 10). Then, the assisting motor provides assistance with a torque of 2 N·m. After the assistance, the pedaling torque of the rider is 10 N·m, maintaining the ideal torque. The assistance of the motor is 2 N·m, providing a total power output of 12 N·m for the bicycle to maintain the original state of riding or climbing.

[0120] When going downhill or coasting, the feet do not pedal, that is, the pedaling force is 0, then the assisting motor does not provide assistance. At this time, the bicycle coasts under the action of inertia.

[0121] The above is an assisting cycle, with a time of 2 - 20 milliseconds. The entire system operates at a frequency of 50 - 500 Hz (that is, it works 50 - 500 times per second) to achieve dynamic sensing and assistance. It has a high working frequency, good smoothness, and no lag phenomenon.

[0122] In order to further improve the user experience and avoid phenomena such as pedaling into empty space, in this application, there is a step S12 between steps S1 and S2. This step S12 includes the following steps:

[0123] Detect the current riding angle through a gyroscope, and automatically select or match a preset starting gear according to the detected angle to achieve starting on different slopes.

[0124] The starting gear is used to achieve starting on different slopes. It has 1 - N gears, where N is 9 or 10, and can be preset according to different scenarios. The starting torque corresponding to each gear is:

[0125]

[0126] Among them, T 启 is the starting torque range of the assisting motor, n is the currently selected gear of the assisting motor, T max is the maximum output torque of the assisting motor, and N is the number of gears;

[0127] That is, it can adapt to the preset gears according to different angles. After adapting to the starting gear, the maximum torque within that gear is used as the starting torque.

[0128] It can quickly select the required gear (torque) according to the current riding slope, obtain the best starting torque, avoid the power lag caused by starting from the minimum torque, or the problem of excessive forward jerk caused by starting from the maximum torque, thereby greatly improving the response speed, the riding smoothness, and the user experience.

[0129] The electric bicycle assisting system of the present invention adopts a continuously variable transmission system and has the following advantages:

[0130] There is no sense of jerk. Through the precise feedback of the torque sensor, the system can adjust the power output in real time to ensure a smooth and silky riding process.

[0131] The structure is simple and does not require a complex mechanical transmission structure, reducing costs and failure rates.

[0132] It efficiently covers a variety of road conditions. The efficient power output of the motor can adapt to various urban road conditions, and can maintain a stable riding experience regardless of how the slope changes.

[0133] Improve riding efficiency. By maintaining a comfortable cadence range, the system can significantly improve riding efficiency and make the rider's ride easier.

[0134] Enhance comfort. The continuously variable transmission system can adjust the power output in real time according to road conditions to ensure no sense of jerk during the riding process and bring an ultimate comfortable experience.

[0135] Adapt to various scenarios. Whether on flat roads, uphill or downhill, the system can maintain stable performance and adapt to various riding scenarios.

[0136] Reduce the learning cost. There is no need to manually switch gears, and even novice riders can easily get started and enjoy a professional-level riding experience.

[0137] At the same time, a self-developed amorphous motor is adopted, which can provide a torque of more than 52 N·m when going uphill, and the highest efficiency reaches 86%. Its efficiency platform is broadened by 120%. In most usage scenarios, the motor can maintain efficient operation. This efficient power output not only improves the riding comfort, but also achieves a true continuously variable transmission effect.

[0138] The electric bicycle assistance system of the present invention avoids the problems of "pedaling into thin air" or "suddenly becoming heavy" of traditional assisted bicycles; and only compensates for torque when needed, reducing ineffective energy consumption; adapts to complex road conditions and improves the riding efficiency in scenarios such as climbing slopes and against the wind.

[0139] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An electric bicycle assist system, characterized in that, Comprising: A torque sensor, arranged at the power input end of the bicycle, for dynamically detecting the torque value at the power input end; An assisting motor, connected to the driving wheel of the bicycle, for assisting the driving wheel; A controller, electrically connected to the torque sensor and the assisting motor respectively, for receiving the torque value and pedaling frequency of the torque sensor, calculating the required motor assisting value, and then providing the corresponding current to the motor according to the assisting value to make the motor output the corresponding torque.

2. The electric bicycle assistance system according to claim 1, wherein: It further includes a gyroscope for detecting the riding slope and then determining the starting torque of the assisting motor by the controller itself.

3. The electric bicycle assist system according to claim 1, characterized in that: The assisting motor is a hub motor, and the hub motor includes: A main shaft, for connecting to the vehicle frame; A hub housing, serving as the output end and for connecting to the wheel, and the hub housing is rotatably mounted on the main shaft; A stator, located inside the hub housing and fixed on the main shaft; A rotor, located inside the hub housing and capable of rotating around the stator; A planetary reduction assembly, arranged between the rotor and the hub housing, for transmitting the power of the rotor to the hub housing and driving the hub housing to rotate; The iron core of the stator and / or the rotor is made of amorphous material.

4. The electric bicycle assistance system according to claim 1, characterized in that: The 80% efficiency platform ratio of the hub motor is greater than 20%.

5. The electric bicycle assistance system according to claim 1, characterized in that: The working frequency of the torque sensor and the assisting motor is 50 - 500 Hz.

6. The electric bicycle assistance system according to claim 1, characterized in that: It further includes a manual control terminal, and the manual control terminal is used to control the opening, closing of the assisting system and the selection or setting of the ideal torque threshold.

7. A power assist method for an electric bicycle power assist system, characterized in that, Including the following steps: S1. Select or set the ideal torque threshold T1, and the ideal torque threshold T1 is the torque value under the desired pedaling feel; S2. The torque sensor detects the torque value T2 at the power input end and compares it with the ideal torque value T1 through the controller; When T2 ≤ T1, it is judged that no assistance is required, and the assisting motor does not assist; When T2 > T1, it is judged that assistance is required, calculate the difference between the two and obtain the required assisting torque T3: T3 = T2 - T1; S3. The controller calculates the current of the assisting motor at the assisting value T3 and transmits it to the assisting motor, so that the output torque of the assisting motor is T3, realizing the synchronous compensation of the torque at the power input end, and further keeping the torque value at the power input end at the ideal torque threshold T1.

8. The assistance method of the electric bicycle assistance system according to claim 7, characterized in that: Steps S2 - S3 constitute an assisting cycle, and the frequency of the assisting cycle is 50 - 500 Hz.

9. The assisting method of the electric bicycle assisting system according to claim 7, characterized in that: There is step S12 between step S1 and S2, and this step S12 includes the following steps: Detect the current riding angle through the gyroscope and automatically select or match the preset starting gear according to the detected angle to achieve different slope starts.

10. The assistance method of the electric bicycle assistance system according to claim 9, characterized in that: The starting gear is used to achieve different slope starts, and it has 1 - N gears, and the starting torque corresponding to each gear is: Among them, T 启 is the starting torque range of the assist motor, n is the currently selected gear of the assist motor, T max is the maximum output torque of the assist motor, and N is the number of gears; After adapting the starting gear, use the maximum torque within this gear as the starting torque.

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