Adaptive electric assistance device and method

Abstract

The application relates to an adaptive electric assisting device and method, which comprises a wheel hub motor, a microprocessor, a motor driving board and an inertial device; the microprocessor is used for receiving a working current and a pitch angle signal, calculating a target output torque of the wheel hub motor, and controlling the motor driving board to adjust the output torque of the wheel hub motor; the inertial device is electrically connected with the microprocessor and is used for collecting a pitch angle and transmitting the pitch angle to the microprocessor; the motor driving board is electrically connected with the wheel hub motor and the microprocessor, is used for driving the wheel hub motor to work, and detects a working current of the wheel hub motor and transmits the working current to the microprocessor. The application can automatically adjust the output torque according to the vehicle load and application scene, does not need manual intervention of a user, can realize automatic adjustment of electric assisting, and improves the use experience of the user.

Description

Technical Field

[0001] This invention relates to the field of vehicle intelligent control technology, specifically to an adaptive electric power assist device and method. Background Technology

[0002] Campervans are a common piece of equipment for outdoor travel and leisure camping, and their convenience and practicality have made them popular among users. Traditional campervans mainly rely on human power to pull them, which can be quite strenuous when carrying heavy loads or on complex terrain. Therefore, electric-assisted technology has been gradually applied to the campervan industry in recent years, becoming an important innovative direction for improving the campervan user experience.

[0003] However, the electric assist systems currently available on electric campervans lack adaptive or automatic adjustment capabilities. In actual use, users must manually adjust the thrust of the electric assist by pressing buttons, depending on the campervan's load capacity and the usage scenario (such as uphill, downhill, or flat ground). This cumbersome and inconvenient operation not only increases the user's workload but also fails to adjust the electric assist output in real-time according to changes in the scenario, resulting in a poor electric assist experience and thus limiting the further promotion and application of electric assist technology in the campervan sector. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, there is an urgent need for an electric assist device and method that can adapt to different loads and application scenarios, and can realize automatic adjustment of electric assist without manual intervention by the user, thus solving the pain points of the existing technology.

[0005] Therefore, the purpose of this invention is to provide an adaptive electric assist device and method to solve the problem that the existing electric assist system of electric camping vehicles requires manual adjustment and is inconvenient to use, so as to realize the adaptive adjustment of electric assist according to load and scene, thereby improving the user experience.

[0006] On one hand, the present invention provides an adaptive electric assist device, including a hub motor, a microprocessor, a motor drive board, and an inertial device; the microprocessor is used to receive operating current and pitch angle signals, calculate the target output torque of the hub motor, and control the motor drive board to adjust the output torque of the hub motor; the inertial device is electrically connected to the microprocessor and is used to acquire the pitch angle and transmit it to the microprocessor; the motor drive board is electrically connected to the hub motor and the microprocessor, and is used to drive the hub motor to work and detect the operating current of the hub motor and transmit it to the microprocessor.

[0007] Furthermore, the inertial device is a six-axis IMU or a nine-axis IMU.

[0008] Furthermore, the motor drive board integrates a current detection module, which is used to detect the operating current of the hub motor and filter the current signal.

[0009] On the other hand, the present invention provides an adaptive electric assist method, implemented based on any of the adaptive electric assist devices described in the first aspect above, comprising the following steps: S1. The motor drive board detects the current operating current of the hub motor and feeds it back to the microprocessor; S2. The inertial device collects the vehicle's current pitch angle and feeds it back to the microprocessor; S3. The microprocessor estimates the current load of the vehicle based on the current operating current, obtains the tilt information of the vehicle based on the current pitch angle, and calculates the current target output torque of the hub motor based on the load and the tilt information. S4. The microprocessor controls the motor drive board to adjust the output torque of the hub motor to the target output torque.

[0010] Further, in step S1, the operating current is the instantaneous current value output by the hub motor, the average current value over a period of time, or the current value after filtering.

[0011] Furthermore, the filtering process is a low-pass filter.

[0012] Furthermore, in step S3, the operating current is positively correlated with the load size.

[0013] Furthermore, in step S3, a positive pitch angle indicates that the vehicle is in an uphill state, and a negative pitch angle indicates that the vehicle is in a downhill state.

[0014] Furthermore, in step S3, the larger the absolute value of the pitch angle, the greater the slope.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. No manual operation by the user is required. By detecting the working current and pitch angle, it automatically identifies the load and usage scenario (uphill, downhill, flat ground) and adaptively adjusts the electric assist torque, solving the pain point of inconvenient manual adjustment in existing technologies.

[0016] 2. The load is estimated by the working current and the slope is identified by the pitch angle. The detection method is simple and reliable, without the need for additional complex detection devices, which reduces the cost of the device and facilitates mass production.

[0017] 3. The electric assist adjustment is smooth and imperceptible, enhancing the user experience and adapting to different loads and terrains, thus expanding the application scope of electric assist technology in the campervan field.

[0018] 4. The detection type of the working current (instantaneous value, average value, filtered value) can be flexibly selected to adapt to different accuracy requirements and improve the adaptability and stability of the device. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the adaptive electric assist device according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating the adaptive electric assist method according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating an application scenario of the adaptive electric assist method according to an embodiment of the present invention. Detailed Implementation

[0021] The description of the embodiments in this specification should be taken in conjunction with the accompanying drawings, which should form part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and may be indicated in a simplified or convenient manner. Furthermore, parts of the various structures in the drawings will be described separately; it is worth noting that elements not shown in the figures or not described in words are in a form known to those skilled in the art.

[0022] The descriptions of the embodiments herein, including any references to directions and orientations, are for ease of description only and should not be construed as limiting the scope of the invention. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination; the invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims.

[0023] like Figure 1The diagram shows the adaptive electric assist device of the present invention, comprising an inertial device 1, a microprocessor 2, a motor drive board 3, and a hub motor 4. The microprocessor 2 receives operating current and pitch angle signals, calculates the target output torque of the hub motor 4, and controls the motor drive board 3 to adjust the output torque of the hub motor 4. The inertial device 1 is electrically connected to the microprocessor 2 and is used to acquire the pitch angle and transmit it to the microprocessor 2. The motor drive board 3 is electrically connected to the hub motor 4 and the microprocessor 2, and is used to drive the hub motor 4 and detect the operating current of the hub motor 4 and transmit it to the microprocessor 2. This device can be used in the electronic control structure of electric camping vehicles, automatically adjusting the output torque according to the vehicle's load and application scenario, achieving automatic adjustment of electric assist without manual user intervention, thus improving the user experience.

[0024] In a preferred embodiment of the present invention, the inertial device 1 is a six-axis IMU or a nine-axis IMU.

[0025] In a preferred embodiment of the present invention, a current detection module 5 is integrated on the motor drive board 3. The current detection module 5 is used to detect the operating current of the hub motor 4 and to filter the current signal.

[0026] like Figure 2 The diagram shows the steps of the adaptive electric assist method of the present invention. This method is implemented based on the above-mentioned device and can be used for self-adjustment of the electric assist output of electric camping vehicles. The steps of this method include: S1, the motor drive board 3 detects the current operating current of the hub motor 4 and feeds it back to the microprocessor 2.

[0027] The operating current is the instantaneous current value output by the hub motor 4, the average current value over a period of time, or the filtered current value. Preferably, the filtering is a low-pass filter to eliminate interference in the current signal and improve detection accuracy.

[0028] S2, Inertial Device 1 collects the vehicle's current pitch angle (refer to...) Figure 3 And feed it back to the microprocessor 2.

[0029] S3, the microprocessor 2 estimates the current load of the vehicle based on the current operating current, and obtains the tilt information of the vehicle based on the current pitch angle. Based on the load and tilt information, it calculates the current target output torque of the hub motor 4.

[0030] The specific calculation logic is as follows: the current load of the campervan is estimated by the operating current. The operating current of the hub motor is positively correlated with the load; the greater the load, the greater the current required for the motor to overcome resistance. The tilt information of the current campervan is obtained by the pitch angle to determine the uphill / downhill state and the slope. A positive pitch angle indicates that the vehicle is uphill, and a negative pitch angle indicates that the vehicle is downhill. The larger the absolute value of the pitch angle, the greater the slope. Combining the load and slope information, a preset torque adjustment algorithm is used to output the target output torque (e.g., the greater the load and the steeper the slope, the greater the target output torque; when going downhill, the output torque is appropriately reduced to avoid excessive vehicle speed).

[0031] S4, the microprocessor 2 controls the motor drive board 3 to adjust the output torque of the hub motor 4 to the target output torque.

[0032] It should be noted that the "magnitude of electric assist thrust" refers to the output torque of the hub motor (torque is the effect of the force that makes an object rotate around an axis, and the unit is N·m). The greater the torque, the stronger the electric assist thrust, which matches the load-bearing and hill-climbing requirements of the campervan. It is not a linear thrust (unit N). Since the hub motor outputs power through rotation, its assist effect is reflected by torque, which is more in line with actual application scenarios.

[0033] The adaptive electric assist device and method of the present invention are described below with reference to specific embodiments. In this embodiment, the specific configuration of the adaptive electric assist device is as follows: 1. Inertial Device (IMU): A nine-axis IMU module, model MPU9250, is used to accurately acquire attitude information such as pitch and roll angles of the campervan. The sampling frequency is 100Hz to ensure the real-time performance and accuracy of attitude detection. The pitch angle signal is transmitted to the microprocessor (MCU) through the I2C interface.

[0034] 2. Hub Motor: A DC brushless hub motor is used, with a rated power of 500W, a rated voltage of 36V, and a maximum output torque of 15N·m, which is suitable for the load requirements of campervans (0-100kg).

[0035] 3. Motor driver board: The BLDC driver board, model DRV8313, is used. It integrates a current detection module (sampling resistor + operational amplifier) ​​and can detect the working current of the hub motor. The detection range is 0-20A. The output instantaneous current, 100ms average current, or current signal after low-pass filtering (cutoff frequency 10Hz) can be selected through software settings. It communicates with the microprocessor (MCU) through the SPI interface.

[0036] 4. Microprocessor (MCU): The core control unit is an STM32F407 microcontroller with a main frequency of 168MHz. It has high-speed computing capabilities, can quickly process current signals and pitch angle signals, execute preset torque adjustment algorithms, and output PWM control signals to the motor drive board to adjust the output torque of the hub motor.

[0037] Based on the above configuration, the specific steps of the adaptive electric assist method in this embodiment are as follows: S1. Current detection: The current detection module on the motor drive board (BLDC drive board) detects the working current of the hub motor in real time. In this embodiment, the output current value after low-pass filtering is selected to eliminate the interference caused by current fluctuations and the filtered current signal is transmitted to the microprocessor (STM32F407 microcontroller).

[0038] S2. Pitch Angle Acquisition: The inertial device (9-axis IMU module MPU9250) acquires the pitch angle signal of the campervan in real time at a sampling frequency of 100Hz, and transmits the pitch angle signal to the microprocessor via the I2C interface. For example, when the campervan is going uphill, the pitch angle is +5°; on flat ground, the pitch angle is 0°; and when going downhill, the pitch angle is -3°.

[0039] S3. Torque Calculation: The microprocessor receives the filtered current signal and pitch angle signal, executes the preset algorithm, and calculates the target output torque.

[0040] Specific algorithm logic: (1) Load estimation: The current-load correspondence is preset. For example, when the current is 2A, the estimated load is 20kg; when the current is 5A, the estimated load is 50kg; when the current is 8A, the estimated load is 80kg. The load of the current camper is accurately estimated based on the real-time current value through the linear interpolation algorithm.

[0041] (2) Slope recognition: Preset the correspondence between pitch angle and slope, for example: pitch angle +3° corresponds to slope 5°; pitch angle +5° corresponds to slope 8°; pitch angle -2° corresponds to slope 3°; determine the slope information of the current terrain based on the real-time pitch angle.

[0042] (3) Target torque calculation: Based on the estimated load and the identified slope, the preset torque adjustment formula is: Target torque T = T0 + k1×m + k2×θ; where T0 is the basic torque when the ground is unloaded (T0 = 2 N·m in this embodiment), k1 is the load factor (k1 = 0.15 N·m / kg in this embodiment), m is the estimated load (kg), k2 is the slope factor (k2 = 0.8 N·m / ° in this embodiment), and θ is the pitch angle (°, positive for uphill and negative for downhill).

[0043] Example 1: On flat ground, with a load of 50kg and a pitch angle θ=0°, the target torque T=2 + 0.15×50 + 0.8×0=9.5N·m; Example 2: Uphill, pitch angle θ = +5°, load 50kg, then the target torque T = 2 + 0.15 × 50 + 0.8 × 5 = 13.5 N·m; Example 3: Downhill, pitch angle θ = -3°, load 50kg, then the target torque T = 2 + 0.15 × 50 + 0.8 × (-3) = 7.1 N·m; S4. Torque Adjustment: The microprocessor outputs a corresponding PWM control signal to the motor drive board based on the calculated target torque T. The motor drive board adjusts the output current of the hub motor, thereby adjusting the output torque of the hub motor to the target torque T, achieving adaptive electric assist. When the load increases or the slope becomes steeper, the target torque automatically increases, and the electric assist is enhanced; when going downhill or the load decreases, the target torque automatically decreases, and the electric assist is weakened. No manual operation is required from the user, achieving a seamless and smooth experience.

[0044] In this embodiment, through the above-described device and method, the electric campervan can automatically identify the load and terrain, and adaptively adjust the electric assist torque: for example, when the load is 50kg and the uphill slope is 8°, the electric assist torque automatically increases to 13.5N·m, and the user can easily pull the campervan without manual adjustment; on flat ground and with a load of 20kg, the electric assist torque automatically adjusts to 5N·m to avoid excessive electric assist causing the vehicle speed to be too high; when going downhill, the electric assist torque automatically decreases to ensure driving safety.

[0045] Tests have shown that the adaptive electric assist device in this embodiment has a fast response speed (≤100ms) and high adjustment accuracy (torque error ≤±0.5N·m), which can effectively solve the problem of inconvenience of manual adjustment in the prior art, improve the user experience, and adapt to the needs of different outdoor camping scenarios.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive electric assist device, characterized in that, It includes an inertial device (1), a microprocessor (2), a motor drive board (3), and a hub motor (4); The microprocessor (2) is used to receive the operating current and pitch angle signals, calculate the target output torque of the hub motor (4), and control the motor drive board (3) to adjust the output torque of the hub motor (4); The inertial device (1) is electrically connected to the microprocessor (2) and is used to collect the pitch angle and transmit it to the microprocessor (2). The motor drive board (3) is electrically connected to the hub motor (4) and the microprocessor (2) to drive the hub motor (4) to work, and to detect the working current of the hub motor (4) and transmit it to the microprocessor (2).

2. The adaptive electric assist device according to claim 1, characterized in that, The inertial device (1) is a six-axis IMU or a nine-axis IMU.

3. The adaptive electric assist device according to claim 1, characterized in that, The motor drive board (3) integrates a current detection module (5), which is used to detect the working current of the hub motor (4) and filter the current signal.

4. An adaptive electric assist method, implemented based on the adaptive electric assist device according to any one of claims 1-3, characterized in that the steps... include: S1. The motor drive board (3) detects the current operating current of the hub motor (4) and feeds it back to the microprocessor (2). S2. The inertial device (1) collects the current pitch angle of the vehicle and feeds it back to the microprocessor (2). S3. The microprocessor (2) estimates the current load of the vehicle based on the current operating current and obtains the tilt information of the vehicle based on the current pitch angle. Based on the load and the tilt information, it calculates the current target output torque of the hub motor (4). S4. The microprocessor (2) controls the motor drive board (3) to adjust the output torque of the hub motor (4) to the target output torque.

5. The adaptive electric assist method according to claim 4, characterized in that, In step S1, the operating current is the instantaneous current value output by the hub motor (4), the average current value over a period of time, or the current value after filtering.

6. The adaptive electric assist method according to claim 5, characterized in that, The filtering process is a low-pass filter.

7. The adaptive electric assist method according to claim 4, characterized in that, In step S3, the operating current is positively correlated with the load.

8. The adaptive electric assist method according to claim 4, characterized in that, In step S3, a positive pitch angle indicates that the vehicle is going uphill, and a negative pitch angle indicates that the vehicle is going downhill.

9. The adaptive electric assist method according to claim 4, characterized in that, In step S3, the larger the absolute value of the pitch angle, the greater the slope.

Images