Motor response control method for power-assisted bicycle

Abstract

The invention relates to a motor response control method for a power-assisted bicycle. The method comprises the steps that a real-time torque value is obtained at intervals; judging whether a preset state signal is a starting signal or not, if the state signal is the starting signal, judging whether the real-time torque value is greater than or equal to a historical torque value or not, and if the real-time torque value is greater than or equal to the historical torque value, generating a corresponding response signal according to the real-time torque value; if the real-time torque value is smaller than the historical torque value, generating a peak value and a corresponding reference value according to the historical torque value, updating the state signal into a stable signal, and generating a corresponding response signal according to the real-time torque value; if the state signal is a stable signal, whether the real-time torque value is larger than a reference value or not is judged, and if the real-time torque value is larger than the reference value, a corresponding response signal is generated according to the real-time torque value; and if the real-time torque value is smaller than or equal to the reference value, generating a corresponding response signal according to the reference value. The method can respond quickly.

Description

Technical Field

[0001] The present application relates to the field of power-assisted bicycles, and in particular to a motor response control method for power-assisted bicycles. Background Art

[0002] Power-assisted bicycles (also known as E-Bikes) are a new type of transportation tool that adds batteries and motors to traditional bicycles. It combines human riding with electric power assistance through a power-assisted system. When the rider steps on the pedals of the power-assisted bicycle, the motor starts working to provide the rider with additional auxiliary power, and the amount of auxiliary power is adjusted according to the rider's needs. Usually, the rider's input torque is sensed by the sensor, and the controller adjusts the motor's output power according to the input torque, so that the motor of the power-assisted bicycle can provide assistance that is suitable for the rider's riding conditions.

[0003] However, the force of the rider when pedaling the power-assisted bicycle pedal is not constant. When the crank of the power-assisted bicycle is perpendicular to the ground and the pedal is at the highest point off the ground, the rider exerts force, and the maximum torque is reached when the crank moves parallel to the ground. Then the rider's force decreases until the pedal moves to the lowest point off the ground, at which time the pedal on the other side is at the highest point off the ground. Therefore, the input torque of the rider on the middle axis collected by the sensor changes periodically (such as Figure 1 Obviously, if the auxiliary power provided by the motor directly follows the input torque collected by the sensor, it will cause an uneven ride. The industry usually uses low-pass filtering to filter the torque signal collected by the sensor to reduce the impact of the input torque reduction on the auxiliary power output during the downward cranking process. However, the use of low-pass filtering to process the torque signal results in a slow response speed, which in turn affects the riding experience of the bicycle. Summary of the invention

[0004] In order to improve the response speed and riding experience, the present application provides a motor response control method for a power-assisted bicycle.

[0005] The present application provides a motor response control method for a power-assisted bicycle, which adopts the following technical solution: A motor response control method for a power-assisted bicycle includes obtaining a real-time torque value at intervals; determining whether a preset state signal is a start signal; If the status signal is a start signal, Determine whether the real-time torque value is greater than or equal to the historical torque value. If the real-time torque value is greater than or equal to the historical torque value, generate a corresponding response signal according to the real-time torque value; if the real-time torque value is less than the historical torque value, generate a peak value and a corresponding reference value according to the historical torque value, update the state signal to a steady signal, set the preset state position to one, and generate a corresponding response signal according to the real-time torque value; If the status signal is a steady signal, Determine whether the real-time torque value is greater than the reference value, if the real-time torque value is greater than the reference value, generate a corresponding response signal according to the real-time torque value; if the real-time torque value is less than or equal to the reference value, generate a corresponding response signal according to the reference value; Determine whether the real-time torque value is greater than the historical torque value. If the real-time torque value is greater than the historical torque value, determine whether the status bit is one. If it is one, set the status bit to zero. If the real-time torque value is less than or equal to the historical torque value, determine whether the status bit is zero. If it is zero, set the status bit to one, and update the peak value and the corresponding reference value according to the historical torque value.

[0006] Optionally, it also includes obtaining the update time of the current time and the peak value, determining whether the difference between the current time and the update time is greater than the preset waiting time, and performing an initialization operation if the difference between the current time and the update time is greater than the waiting time.

[0007] Optionally, the initialization operation includes setting the status position to zero, switching the status signal to a start signal, setting the peak value to zero and updating the reference value, and setting the current time and the update time to zero.

[0008] Optionally, the reference value is defined according to a peak value, and the reference value is equal to the peak value multiplied by a response function, and the response function is a decreasing function with respect to time.

[0009] Optionally, the reference value is defined by a peak value, the reference value is equal to the peak value multiplied by a response coefficient, and the response coefficient is less than one.

[0010] Optionally, the response coefficient is preferably 60%-95%.

[0011] The present application provides a control system for a power-assisted bicycle, which adopts the following technical solution: A control system for a power-assisted bicycle, comprising: Torque sensor, used to detect the torque of the middle shaft and output the corresponding real-time torque value; A processor, configured to receive the real-time torque value and generate a corresponding response signal according to the above-mentioned motor response control method for a power-assisted bicycle; and The motor controller is used to receive the response signal and control the output power of the motor according to the response signal.

[0012] By adopting the above technical solution, the motor can respond quickly to the detected torque signal. At the same time, the auxiliary power output by the motor according to the response signal is smooth and without setbacks, which greatly improves the riding experience of the rider. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the torque signal of the middle shaft of the power-assisted bicycle.

[0014] Figure 2 The invention is a schematic diagram of a response signal obtained according to a control system for an electric power-assisted bicycle, wherein a reference value is defined according to a peak value and a response function.

[0015] Figure 3 The invention is a schematic diagram of a response signal obtained according to a control system for a power-assisted bicycle, wherein a reference value is defined according to a peak value and a response coefficient. DETAILED DESCRIPTION

[0016] The following is combined with Figure 1-3 , further details of this application are given.

[0017] The embodiment of the present application discloses a control system for a power-assisted bicycle, which includes a torque sensor, a processor, and a motor controller.

[0018] The torque sensor can be a stress strain torque sensor, a magnetoresistive torque sensor, etc., which collects the torque on the central axis of the power-assisted bicycle and outputs the corresponding real-time torque value to the processor. The central axis torque signal collected by the torque sensor is as follows: Figure 2 and Figure 3 As shown by the dotted line in the middle, although the torque signal changes periodically, the cycle time and cycle amplitude are not necessarily the same.

[0019] The processor receives the real-time torque value from the torque sensor, generates a response signal according to the motor response control method, and transmits the response signal to the motor controller. Figure 2 or Figure 3 Indicated by the solid line.

[0020] The motor controller receives the response signal, controls the output power and speed of the motor according to the response signal, and transmits the auxiliary power to the central shaft through the motor transmission structure.

[0021] The processor generates a response signal using a motor response control method for a power-assisted bicycle, which specifically includes the following steps.

[0022] Perform power-on initialization operations, including setting the status position to zero, switching the status signal to a start signal, and setting the time T to zero.

[0023] The real-time torque value Qn is obtained at intervals, where the interval can be set to 2ms.

[0024] It is determined whether a preset state signal is a start signal, wherein an initial value of the state signal is the start signal.

[0025] If the status signal is a starting signal, determine whether the real-time torque value Qn is greater than the historical torque value Qn-1; if the real-time torque value Qn is greater than or equal to the historical torque value Qn-1, generate a corresponding response signal according to the real-time torque value Qn; if the real-time torque value Qn is less than the historical torque value Qn-1, generate a peak value Qmax and a corresponding reference value Qref according to the historical torque value Qn-1, and at the same time update the status signal to a steady signal, set the preset status position to one, and generate a corresponding response signal according to the real-time torque value Qn.

[0026] When the status signal is a starting signal, a response signal is generated according to the real-time torque value Qn. Among them, the historical torque value Qn-1 is the torque value obtained at the previous time, and the initial value of the status bit is zero. When the real-time torque value Qn is greater than or equal to the historical torque value Qn-1, and the status bit is zero, it is judged that it is at the rising edge of the torque signal at this time. When the real-time torque value Qn is less than the historical torque value Qn-1, and the status bit is one, it is judged that it is at the falling edge of the torque signal at this time. At this time, the historical torque value Qn-1 is assigned the peak value Qmax, and the reference value Qref is defined according to the peak value Qmax. At the same time, the status signal is updated to a steady signal. Since the interval time is set short, the error between the actual peak of the torque signal and the maximum historical torque value obtained is ignored to quickly respond to the torque signal.

[0027] The reference value Qref can be defined in different ways.

[0028] Method 1: The reference value Qref is equal to the peak value Qmax multiplied by the response function F(t), and the response function F(t) is a decreasing function (such as e -kt ), the response function F(t) is a time function about the difference time, where the difference time is equal to the current time minus the update time of the peak value. It should be noted that the response function can be other functions that decrease monotonically, not limited to the above example functions, and can be a curve function or a straight line function. At this time, the exemplary waveform of the response signal is as follows Figure 2 Shown as solid line.

[0029] Method 2: The reference value Qref is equal to the peak value Qmax multiplied by the response coefficient β. The response coefficient β is preferably 60%-95%. In this embodiment, the response coefficient β is 95%. At this time, the exemplary waveform of the response signal is as follows: Figure 3 Shown as solid line.

[0030] If the status signal is a steady signal, determine whether the real-time torque value Qn is greater than the reference value Qref. If the real-time torque value Qn is greater than the reference value Qref, generate a corresponding response signal according to the real-time torque value Qn; if the real-time torque value Qn is less than or equal to the reference value Qref, generate a corresponding response signal according to the reference value Qref; determine whether the real-time torque value Qn is greater than the historical torque value Qn-1. If the real-time torque value Qn is greater than the historical torque value Qn-1, determine whether the status bit is one. If it is one, set the status bit to zero; if the real-time torque value Qn is less than or equal to the historical torque value Qn-1, determine whether the status bit is zero. If it is zero, set the status bit to one, and update the peak value Qmax and the corresponding reference value Qref according to the historical torque value Qn-1.

[0031] When the state signal is a steady signal, the real-time torque value Qn is compared with the reference value Qref. When the real-time torque value Qn is greater than the reference value Qref, a response signal is generated according to the real-time torque value Qn. If the real-time torque value Qn is less than or equal to the reference value Qref, a response signal is generated according to the reference value Qref to eliminate the influence of the input torque reduction on the auxiliary power output during the cranking process. The example waveform of the response signal is as follows: Figure 2 As shown, the solid line represents the response signal and the dotted line represents the torque signal.

[0032] Get the current time Tn and the update time Tq of the peak value, and determine whether the difference between the current time Tn and the update time Tq is greater than the preset waiting time Tw. If the difference between the current time Tn and the update time Tq is greater than the waiting time Tw, perform the initialization operation, that is, set the state position to zero, switch the state signal to the start signal, set the peak value Qmax to zero and update the reference value Qref, and set the current time Tn and the update time Tq to zero.

[0033] If the peak value is not updated for a long time, it may be that the rider no longer inputs torque; when riding downhill, after a waiting time of more than 3 seconds, the initialization operation is performed. When the rider starts riding again, the judgment is returned to the initial step.

[0034] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A motor response control method for a power-assisted bicycle, characterized in that: include Get the real-time torque value at intervals; determine whether the preset status signal is a starting signal, If the status signal is a start signal, Determine whether the real-time torque value is greater than or equal to the historical torque value, and if the real-time torque value is greater than or equal to the historical torque value, generate a corresponding response signal according to the real-time torque value; If the real-time torque value is less than the historical torque value, a peak value and a corresponding reference value are generated according to the historical torque value, the state signal is updated to a steady signal, the preset state position is set to one, and a corresponding response signal is generated according to the real-time torque value; If the status signal is a steady signal, Determine whether the real-time torque value is greater than the reference value, and if the real-time torque value is greater than the reference value, generate a corresponding response signal according to the real-time torque value; If the real-time torque value is less than or equal to the reference value, a corresponding response signal is generated according to the reference value; Determine whether the real-time torque value is greater than the historical torque value. If the real-time torque value is greater than the historical torque value, determine whether the status bit is one. If it is one, set the status bit to zero. If the real-time torque value is less than or equal to the historical torque value, determine whether the status bit is zero. If it is zero, set the status bit to one and update the peak value and the corresponding reference value according to the historical torque value.

2. A motor response control method for a power-assisted bicycle according to claim 1, characterized in that: It also includes obtaining the update time of the current time and the peak value, judging whether the difference between the current time and the update time is greater than the preset waiting time, and performing an initialization operation if the difference between the current time and the update time is greater than the waiting time.

3. A motor response control method for a power-assisted bicycle according to claim 2, characterized in that: The initialization operation includes setting the state position to zero, switching the state signal to a start signal, setting the peak value to zero and updating the reference value, and setting the current time and the update time to zero.

4. A motor response control method for a power-assisted bicycle according to claim 2, characterized in that: The reference value is defined according to the peak value, and the reference value is equal to the peak value multiplied by a response function, wherein the response function is a decreasing function with respect to time.

5. A motor response control method for a power-assisted bicycle according to claim 1 or 2, characterized in that: The reference value is defined by the peak value, the reference value being equal to the peak value multiplied by a response factor, the response factor being less than one.

6. A motor response control method for a power-assisted bicycle according to claim 5, characterized in that: The response coefficient is preferably 60%-95%.

7. A control system for a power-assisted bicycle, characterized in that: include Torque sensor, used to detect the torque of the middle shaft and output the corresponding real-time torque value; A processor, configured to receive the real-time torque value and generate a corresponding response signal according to the motor response control method for a power-assisted bicycle according to claims 1-6; and The motor controller is used to receive the response signal and control the output power of the motor according to the response signal.

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