Control method of rollator

Abstract

The invention discloses a control method of a rollator, which solves the technical problems that the existing rollator is complicated in structure and high in manufacturing cost, and comprises a controller for controlling a left motor and a right motor based on field-oriented control, the controller monitors the acceleration and the speed of the left driving wheel and the right driving wheel through detection signals of Hall sensors or encoders arranged in the left motor and the right motor; or the controller monitors the acceleration and the speed of the left driving wheel and the right driving wheel through a three-phase voltage back electromotive force zero-crossing interval; the control method comprises the steps that the controller controls the left motor and the right motor to input the same torque current, the left driving wheel and the right driving wheel are kept to run at the same speed and acceleration, and the acceleration and the speed of the left driving wheel and the right driving wheel are monitored in real time; when the left driving wheel and the right driving wheel have speed difference and / or acceleration difference, turning judgment of the controller is triggered; the controller compensates the torque current of the left motor and / or the right motor according to the turning judgment result, and turning assistance is provided for the rollator.

Description

Technical Field

[0001] The present invention relates to the field of auxiliary vehicle control, and particularly to a control method for an auxiliary vehicle. Background Art

[0002] A power assist control method for an intelligent auxiliary vehicle is disclosed in the prior art. The auxiliary vehicle includes a vehicle body, a left drive wheel, a right drive wheel, a left motor, a right motor, a left driven wheel, a right driven wheel, and a controller. The left drive wheel and the right drive wheel are spaced apart in the width direction at the rear side of the vehicle body. The left motor is connected to the left drive wheel to provide a power assist torque, and the right motor is connected to the right drive wheel to provide a power assist torque. The left driven wheel and the right driven wheel are spaced apart in the width direction at the front side of the vehicle body. The controller controls the left motor and the right motor. In addition, an accelerometer is provided on the vehicle body. The acceleration sensors of the accelerometer can obtain the acceleration of the left drive wheel and the acceleration of the right drive wheel. The controller can judge the steering of the auxiliary vehicle according to the speed difference between the left drive wheel and the right drive wheel, and realize the steering assist of the auxiliary vehicle by adjusting the left drive wheel steering compensation value and / or the right drive wheel steering compensation value to facilitate steering. It can be seen from this that the auxiliary vehicle control method in the prior art needs to add an additional accelerometer on the vehicle body for acceleration detection, with a relatively complex structure and a high manufacturing cost. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a control method for an auxiliary vehicle without setting an additional accelerometer, so as to simplify the structure of the auxiliary vehicle and reduce the manufacturing cost.

[0004] To solve the above technical problem, the present invention adopts the following technical solutions: A control method for an auxiliary vehicle, the auxiliary vehicle including: A vehicle body; A left drive wheel and a right drive wheel, spaced apart in the width direction at the rear side of the vehicle body; A left motor and a right motor, respectively connected to the left drive wheel and the right drive wheel to provide a power assist torque; A left driven wheel and a right driven wheel, spaced apart in the width direction at the front side of the vehicle body; Further including: A controller, controlling the left motor and the right motor based on field-oriented control. The controller monitors the acceleration and speed of the left drive wheel and the right drive wheel through the detection signals of the Hall sensors or encoders built in the left motor and the right motor; alternatively, the controller monitors the acceleration and speed of the left drive wheel and the right drive wheel through the zero-crossing interval of the back electromotive force of the three-phase voltage; The control method includes: The controller controls the left and right motors to input the same torque current, keeps the left and right drive wheels running at the same speed and acceleration, and monitors the acceleration and speed of the left and right drive wheels in real time; When there is a speed difference and / or an acceleration difference between the left and right drive wheels, it triggers the turning determination of the controller; The controller compensates the torque current of the left motor and / or the right motor according to the turning determination result to provide turning assistance for the mobility aid.

[0005] The controller in the present invention controls the left and right motors based on field-oriented control, and field-oriented control is a high-performance control technology for AC motors (such as permanent magnet synchronous motors). By decomposing the current of the motor into independent magnetic field components (i.e., excitation current) and torque components (torque current), precise control of the motor torque and magnetic field is achieved. Among them, the torque current is mainly responsible for generating the torque of the motor, thereby affecting the acceleration and speed of the drive wheels. In a motor using field-oriented control, the speed and acceleration of the rotor are detected by measuring the magnetic field change of the permanent magnet rotating with the rotor through its built-in Hall sensor, or through an encoder, or the controller according to the zero-crossing interval of the back electromotive force of the three-phase voltage. Thus, the acceleration and speed of the drive wheels are detected in real time, and when there is a speed difference and / or an acceleration difference between the left and right drive wheels, it triggers the turning determination of the controller, so that the controller compensates the torque current of the left motor and / or the right motor according to the turning determination result to provide turning assistance for the mobility aid. That is, in this application, the controller controls the left and right motors based on field-oriented control, and uses the built-in Hall sensor or encoder or the controller to detect the acceleration and speed of the left and right drive wheels according to the zero-crossing interval of the back electromotive force of the three-phase voltage, without adding an additional sensor - accelerometer on the vehicle body, thereby simplifying the structure of the mobility aid and reducing the manufacturing cost.

[0006] Finally, since the control logic of the mobility aid is based on field-oriented control technology, there is no need for a complex human-machine interaction interface or operation interface. This makes the operation of the mobility aid more intuitive and natural, and the user can control the mobility aid only through body movements; the advantage of this control method lies in its intuitiveness and ease of use. The user does not need to learn how to operate a complex control interface, but can directly interact with the mobility aid through body language. This not only improves the user experience of the mobility aid, but also can reduce the manufacturing cost because it reduces the need for additional sensors and complex control interfaces.

[0007] In the above control method of the mobility aid, when it is determined that the mobility aid turns left, the torque current of the left motor is reduced and / or the torque current of the right motor is increased; When it is determined that the mobility aid turns right, the torque current of the right motor is reduced and / or the torque current of the left motor is increased.

[0008] Left-turn control strategy: When it is determined that the assisted vehicle turns left, reducing the torque current of the left motor will cause the speed of the left driving wheel to decrease. Since the left driving wheel decelerates, the vehicle will tend to deflect to the left. Similarly, increasing the torque current of the right motor will increase the speed of the right driving wheel, and due to the acceleration of the right driving wheel, the vehicle will also tend to deflect to the left. If the torque current of the left motor is reduced while the torque current of the right motor is increased, the left-turning trend of the vehicle will be further enhanced. The combined effect of the acceleration of the right driving wheel and the deceleration of the left driving wheel enables the assisted vehicle to turn left smoothly.

[0009] Right-turn control strategy: When it is determined that the assisted vehicle turns right, reducing the torque current of the right motor will cause the speed of the right driving wheel to decrease, which will make the vehicle tend to deflect to the right. Similarly, if the torque current of the left motor is increased, the speed of the left driving wheel will increase, and the vehicle will also tend to deflect to the right. If the torque current of the right motor is reduced while the torque current of the left motor is increased, the right-turning trend of the vehicle will be further enhanced. The combined effect of the acceleration of the left driving wheel and the deceleration of the right driving wheel enables the assisted vehicle to turn right smoothly. The advantages of this control method are as follows: Flexibility: By precisely controlling the torque current of the motor, precise steering control can be achieved, improving the maneuverability and flexibility of the assisted vehicle.

[0010] Robustness: Reducing the dependence on external sensors enables the system to maintain stable steering performance under different road conditions and speeds.

[0011] Energy saving: By reasonably distributing the torque current of the left and right motors, unnecessary energy consumption can be reduced, improving the energy efficiency of the assisted vehicle.

[0012] In the above control method of the assisted vehicle, the torque current compensation value of the left motor is based on the speed of the left driving wheel, and the torque current compensation value of the right motor is based on the speed of the right driving wheel; When it is determined that the assisted vehicle turns left, the torque current of the left motor is reduced in proportion to the speed of the left driving wheel, and the torque current of the right motor is increased in proportion to the speed of the right driving wheel; When it is determined that the assisted vehicle turns right, the torque current of the left motor is increased in proportion to the speed of the left driving wheel, and the torque current of the right motor is reduced in proportion to the speed of the right driving wheel.

[0013] With such a design, by linking the adjustment of the torque current to the actual speed of the driving wheel, precise control of the steering behavior of the assisted vehicle is achieved. This method not only improves the maneuverability of the assisted vehicle but also enhances its stability and adaptability at different speeds and conditions.

[0014] In the above control method of the assisted vehicle, it is defined that when the left and right motors input the same torque current as Iq, the speed of the left driving wheel is vL, and the speed of the right driving wheel is vR; When the rollator turns left, adjust the torque current of the left drive wheel IqL=Iq vL / vR, adjust the torque current of the right driving wheel IqR=Iq vR / vL; When the rollator turns right, adjust the torque current of the left drive wheel IqL=Iq vL / vR, adjust the torque current of the right driving wheel IqR=Iq vR / vL.

[0015] This design adjusts the torque current proportionally so that the speed difference between the left and right drive wheels can adapt to the needs of turning. Since the torque current is adjusted based on the speed ratio, taking into account the actual speed of the left and right drive wheels, this strategy can achieve smoother and more natural steering, improving the maneuverability and stability of the rollator.

[0016] In the above control method of the rollator, when the rollator is pushed in the first direction, the controller's power assist determination is triggered, the left motor and the right motor are controlled to input the same torque current, the left drive wheel and the right drive wheel are provided with power assist torque consistent with the first direction, the speed of the left drive wheel and the right drive wheel are monitored in real time, and the torque current is adjusted in real time according to the speed change of the left drive wheel and the right drive wheel. With such a design, the rollator can also realize adaptive power assist operation without relying on additional sensors for moving forward or backward, so that the rollator can adaptively follow the user's footsteps.

[0017] In the above-mentioned method for controlling the rollator, adjusting the torque current in real time according to the speed change of the left driving wheel and the right driving wheel includes: Obtaining the acceleration or deceleration of the rollator in the first direction according to the speed changes of the left driving wheel and the right driving wheel, wherein the acceleration indicates that the rollator is accelerating, and the deceleration indicates that the rollator is decelerating; If the walker is accelerated, the torque current of the left motor and the right motor is positively compensated in proportion to the acceleration; If the mobility assisted vehicle is decelerated and pushed, the torque currents of the left and right motors are negatively compensated in direct proportion to the deceleration.

[0018] This design can improve the responsiveness of the rollator, allowing it to adapt to the user's pushing needs more quickly. Through precise torque current compensation, the rollator can provide a smoother and more natural pushing feeling, reducing the user's pushing burden.

[0019] In the above control method of the assisted bicycle, when the assisted bicycle is pushed in the first direction and then pushed in the opposite second direction, first, the torque currents of the left motor and the right motor are negatively compensated in proportion to the deceleration until the assist torque in the first direction becomes zero; as the assisted bicycle continues to be pushed in the second direction, the left motor and the right motor are controlled to input the same torque current to provide an assist torque for the left drive wheel and the right drive wheel that is consistent with the second direction, and the speeds of the left drive wheel and the right drive wheel are monitored in real time, and the torque current is adjusted in real time according to the speed changes of the left drive wheel and the right drive wheel. With such a design, when the assisted bicycle changes from the first direction to the second direction, the controller will first negatively compensate the torque currents of the left motor and the right motor according to the ratio of the deceleration. This compensation is to smoothly reduce the assist in the original direction when the pushing direction changes, so as to avoid discomfort to the rider caused by sudden changes in assist.

[0020] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the drawings: Figure 1 It is a schematic structural diagram of the assisted bicycle in Embodiment 1 of the present invention.

[0022] Reference numerals: 100, vehicle body; 200, left drive wheel; 300, right drive wheel; 400, left motor; 500, right motor; 600, left driven wheel; 700, right driven wheel; 800, controller. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention provides a control method for an assisted bicycle, and the assisted bicycle includes: A vehicle body; A left drive wheel and a right drive wheel, which are spaced apart in the width direction at the rear side of the vehicle body; A left motor and a right motor, which are respectively connected to the left drive wheel and the right drive wheel to provide assist torque; A left driven wheel and a right driven wheel, which are spaced apart in the width direction at the front side of the vehicle body; It further includes: A controller, which controls the left motor and the right motor based on field-oriented control. The controller monitors the accelerations and speeds of the left drive wheel and the right drive wheel through the detection signals of Hall sensors or encoders built in the left motor and the right motor; alternatively, the controller monitors the accelerations and speeds of the left drive wheel and the right drive wheel through the zero-crossing intervals of the back electromotive force of the three-phase voltage. The control method includes: The controller controls the left motor and the right motor to input the same torque current, keeps the left drive wheel and the right drive wheel running at the same speed and acceleration, and monitors the acceleration and speed of the left drive wheel and the right drive wheel in real time; When there is a speed difference and / or an acceleration difference between the left drive wheel and the right drive wheel, the turning determination of the controller is triggered; The controller compensates the torque current of the left motor and / or the right motor according to the turning determination result to provide turning assistance for the assisted vehicle.

[0024] The controller in the present invention controls the left motor and the right motor based on field-oriented control, and field-oriented control is a high-performance control technology for AC motors (such as permanent magnet synchronous motors). By decomposing the current of the motor into independent magnetic field components (i.e., excitation current) and torque components (torque current), precise control of the motor torque and magnetic field is achieved. Among them, the torque current is mainly responsible for generating the torque of the motor, thereby affecting the acceleration and speed of the drive wheel. In a motor using field-oriented control, the speed and acceleration of the rotor are detected by measuring the magnetic field change of the permanent magnet rotating with the rotor through its built-in Hall sensor, or through an encoder, or the controller based on the zero-crossing interval of the back electromotive force of the three-phase voltage. Thus, the acceleration and speed of the drive wheel are detected in real time, and when there is a speed difference and / or an acceleration difference between the left drive wheel and the right drive wheel, the turning determination of the controller is triggered, so that the controller compensates the torque current of the left motor and / or the right motor according to the turning determination result to provide turning assistance for the assisted vehicle. That is, in this application, the controller controls the left motor and the right motor based on field-oriented control, and uses the built-in Hall sensor or encoder or the controller based on the zero-crossing interval of the back electromotive force of the three-phase voltage to detect the acceleration and speed of the left drive wheel and the right drive wheel, without additionally adding a sensor - accelerometer on the vehicle body, thereby simplifying the structure of the assisted vehicle and reducing the manufacturing cost.

[0025] Finally, since the control logic of the assisted vehicle is based on field-oriented control technology, a complex human-machine interaction interface or operation interface is not required. This makes the operation of the assisted vehicle more intuitive and natural, and the user only needs to control the assisted vehicle through body movements; the advantage of this control method lies in its intuitiveness and ease of use. The user does not need to learn how to operate a complex control interface, but can directly interact with the assisted vehicle through body language. This not only improves the user experience of the assisted vehicle, but also reduces the manufacturing cost because it reduces the need for additional sensors and complex control interfaces.

[0026] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings of the embodiments of the present invention. However, the following embodiments are only the preferred embodiments of the present invention and not all of them. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present invention. In addition, it should be understood that the following terms indicating orientation or positional relationships, such as "upper", "lower", "left", "right", "longitudinal", "lateral", "inner", "outer", "vertical", "horizontal", "top", "bottom", etc., are only based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device / element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0027] Embodiment 1: As Figure 1 shown, the walking aid in this embodiment includes a vehicle body 100, a left drive wheel 200, a right drive wheel 300, a left motor 400, a right motor 500, a left driven wheel 600, a right driven wheel 700, and a controller 800. The left drive wheel 200 and the right drive wheel 300 are respectively rotatably installed on the vehicle body 100 and are spaced apart in the width direction at the rear side of the vehicle body 100; the left motor 400 is connected to the left drive wheel 200 to provide an assist torque to drive the left drive wheel 200 to rotate, and the right motor 500 is connected to the right drive wheel 300 to provide an assist torque to drive the right drive wheel 300 to rotate; the left driven wheel 600 and the right driven wheel 700 are respectively rotatably installed on the vehicle body 100 and are spaced apart in the width direction at the front side of the vehicle body 100; and the controller 800 controls the left motor 400 and the right motor 500 based on field-oriented control. The controller 800 monitors the acceleration a and speed v of the left drive wheel 200 and the right drive wheel 300 through the detection signals of the Hall sensors or encoders built in the left motor 400 and the right motor 500; alternatively, the controller 800 monitors the acceleration a and speed v of the left drive wheel 200 and the right drive wheel 300 through the zero-crossing intervals of the back electromotive force of the three-phase voltage. The control method of the walking aid in this embodiment includes: The controller 800 controls the left motor 400 and the right motor 500 to input the same torque current Iq, keeps the left drive wheel 200 and the right drive wheel 300 running at the same speed v and acceleration a, and monitors the acceleration a and speed v of the left drive wheel 200 and the right drive wheel 300 in real time; when a speed difference and / or an acceleration difference occur between the left drive wheel 200 and the right drive wheel 300, the turning determination of the controller 800 is triggered; the controller 800 compensates the torque current Iq of the left motor 400 and / or the right motor 500 according to the turning determination result to provide turning assistance for the walking aid.

[0028] The controller 800 in this embodiment controls the left motor 400 and the right motor 500 based on field-oriented control. The left motor 400 and the right motor 500 are permanent magnet synchronous motors, and field-oriented control is a high-performance control technology for AC motors. By decomposing the current of the motor into independent magnetic field components (i.e., excitation current) and torque components (torque current Iq), precise control of the motor torque and magnetic field is achieved. Among them, the torque current is mainly responsible for generating the torque of the motor, thereby affecting the acceleration and speed of the drive wheels.

[0029] In a motor using field-oriented control, the motor usually has Hall sensors and permanent magnets that rotate with the rotor built in; or an encoder is built in, and the input shaft of the encoder rotates synchronously with the rotor. The speed and acceleration of the rotor are detected by measuring the magnetic field change of the permanent magnet rotating with the rotor through the Hall sensors built in the motor or through the encoder or the controller based on the zero-crossing interval of the back electromotive force of the three-phase voltage, so as to achieve real-time detection of the acceleration a and speed v of the drive wheels. When a speed difference and / or acceleration difference occurs between the left drive wheel 200 and the right drive wheel 300, the turning determination of the controller 800 is triggered, so that the controller 800 compensates the torque current Iq of the left motor 400 and / or the right motor 500 according to the turning determination result, providing turning assistance for the mobility aid. That is, in this embodiment, the controller 800 controls the left motor 400 and the right motor 500 based on field-oriented control, and the acceleration a and speed v of the left drive wheel 200 and the right drive wheel 300 can be detected by using the Hall sensors or encoders built in the dual motors or the controller based on the zero-crossing interval of the back electromotive force of the three-phase voltage, without adding an additional sensor - accelerometer on the vehicle body 100, thus simplifying the structure of the mobility aid and reducing the manufacturing cost.

[0030] Finally, since the control logic of the mobility aid is based on field-oriented control technology, a complex human-machine interaction interface or operation interface is not required. This makes the operation of the mobility aid more intuitive and natural, and the user only needs to control the mobility aid through body movements; the advantage of this control method lies in its intuitiveness and ease of use. The user does not need to learn how to operate a complex control interface, but can directly interact with the mobility aid through body language. This not only improves the user experience of the mobility aid, but also reduces the manufacturing cost because it reduces the need for additional sensors and complex control interfaces.

[0031] Specifically, according to the field-oriented control technology, a torque current Iq and an excitation current Id are respectively injected into the motor stator. The work done by the torque current Iq is reflected in the acceleration and speed of the driving wheel. Given the quadrature inductance Lq and direct-axis inductance Ld of the motor, according to the motor torque equation Te = 1.5P[Ke + (Ld - Lq)Id]Iq, where P is the number of pole pairs of the motor, Ke is the back electromotive force constant of the motor, Ld is the direct-axis inductance of the motor, Lq is the quadrature inductance of the motor, Id is the excitation current, and Iq is the torque current, the torque Te of the current motor can be obtained. It can be seen from this that the larger the input torque current Iq, the greater the acceleration a under the same resistance, and the higher the achievable speed v.

[0032] In this embodiment, taking the use of a Hall sensor to detect the acceleration a and speed V of the rotor as an example for illustration: The calculation method is as follows: Given that the rotation interval time of the N pole and S pole of the magnet on the rotor is Ts, then the magnet rotation frequency F = 1 / Ts, and the current moment v = (F × 60) / P, where P is the number of pole pairs of the motor, and the acceleration a = (V1 - V2) / T, where T is the time taken for the speed to change from V1 to V2.

[0033] For the controller 800 to monitor the acceleration a and speed v of the left driving wheel 200 and the right driving wheel 300 through the zero-crossing interval of the three-phase voltage back electromotive force, it belongs to the prior art and will not be elaborated here.

[0034] After the walking aid starts to be pushed, the controller 800 controls the left motor 400 and the right motor 500 to input the same torque current Iq to the left driving wheel 200 and the right driving wheel 300 respectively, and the left driving wheel 200 and the right driving wheel 300 generate the same acceleration a and speed v.

[0035] When the user turns left, the left hand will pull and the right hand will push. At this time, since the initial torque current Iq injected into the two wheels is the same, the initial speeds v and accelerations a of the two wheels are also the same. However, after turning left, the external resistance will change. The speed v and acceleration a of the left drive wheel 200 will both decrease, and the speed v and acceleration a of the right drive wheel 300 will both increase. That is, the speed v and acceleration a of the left drive wheel 200 are less than the speed v and acceleration a of the right drive wheel 300. At this time, a speed difference and an acceleration difference will be generated on both sides simultaneously, which will trigger the turning determination of the controller 800. After the controller 800 determines that the speed v and acceleration a of the left drive wheel 200 are less than the speed v and acceleration a of the right drive wheel 300, it can determine that the mobility aid turns left. Subsequently, the controller 800 compensates the torque currents of the left motor 400 and the right motor 500, that is, reduces the torque current Iq of the left motor 400 while increasing the torque current Iq of the right motor 500. Reducing the torque current Iq of the left motor 400 will cause the speed of the left drive wheel 200 to decrease. Since the left drive wheel 200 decelerates, the vehicle will tend to deflect to the left. Increasing the torque current Iq of the right motor 500 will cause the speed of the right drive wheel 300 to increase. Since the right drive wheel 300 accelerates, it will also cause the vehicle to tend to deflect to the left. Therefore, when reducing the torque current Iq of the left motor 400 while increasing the torque current Iq of the right motor 500, the turning trend of the vehicle to the left will be further enhanced. The combined action of the acceleration of the right drive wheel 300 and the deceleration of the left drive wheel 200 enables the mobility aid to turn left smoothly, providing assistance for the left turn of the mobility aid.

[0036] It can be understood that in other embodiments of the present invention, during the turning determination process of the mobility aid, it is also possible to only judge based on the speed difference that appears between the left drive wheel and the right drive wheel. If the speed of the left drive wheel is greater than the speed of the right drive wheel, it is determined that the mobility aid turns right; otherwise, it is determined that the mobility aid turns left. In addition, during the turning determination process of the mobility aid, it is also possible to only judge based on the acceleration difference that appears between the left drive wheel and the right drive wheel. If the acceleration of the left drive wheel is greater than the acceleration of the right drive wheel, it is determined that the mobility aid turns right; otherwise, it is determined that the mobility aid turns left. Since acceleration is a process quantity and speed is a result quantity, if only the speed difference or acceleration difference is used to determine the turning, there may be a problem of inaccurate judgment. Therefore, in this application, it is preferably determined based on the speed difference and acceleration difference to improve the accuracy of the determination result.

[0037] It can be understood that in other embodiments of the present invention, after determining that the mobility aid turns left, it is also possible to only compensate the torque current of the left motor (reduce the torque current of the left motor) or only compensate the torque current of the right motor (increase the torque current of the right motor) by the controller to provide turning assistance for the mobility aid. Similarly, when the user turns right, the right hand pulls and the left hand pushes. At this time, since the torque currents Iq injected into the two wheels are the same, but the external resistance has changed, the speed v and acceleration a of the right drive wheel 300 will both decrease, and the speed v and acceleration a of the left drive wheel 200 will both increase, that is, the speed v and acceleration a of the left drive wheel 200 are greater than those of the right drive wheel 300. At this time, a speed difference and an acceleration difference will be generated on both sides, which will trigger the turning determination of the controller 800. After the controller 800 determines that the speed v and acceleration a of the left drive wheel 200 are greater than those of the right drive wheel 300, it can determine that the mobility aid turns right. Subsequently, the controller 800 compensates the torque currents Iq of the left motor 400 and the right motor 500, that is, reduces the torque current Iq of the right motor 500 while increasing the torque current Iq of the left motor 400. By reducing the torque current Iq of the right motor 500, the speed of the right drive wheel 300 will decrease. Since the right drive wheel 300 decelerates, the vehicle will tend to deflect to the right. By increasing the torque current Iq of the left motor 400, the speed of the left drive wheel 200 will increase. Since the left drive wheel 200 accelerates, it will also make the vehicle tend to deflect to the right. Therefore, while increasing the torque current Iq of the left motor 400 and reducing the torque current Iq of the right motor 500, the turning trend of the vehicle to the right will be further enhanced. The combined effect of the deceleration of the right drive wheel 300 and the acceleration of the left drive wheel 200 enables the mobility aid to turn right smoothly, providing assistance for the right turn of the mobility aid.

[0038] It can be understood that in other embodiments of the present invention, after determining that the mobility aid turns right, the controller can also provide turning assistance for the mobility aid by only compensating the torque current of the left motor (increasing the torque current of the left motor), or only compensating the torque current of the right motor (reducing the torque current of the right motor).

[0039] The advantages of the left-turn and right-turn control methods in this embodiment are as follows: Flexibility: By precisely controlling the torque current of the motor, precise steering control can be achieved, improving the maneuverability and flexibility of the mobility aid.

[0040] Robustness: Reducing the dependence on external sensors enables the system to maintain stable steering performance under different road conditions and speeds.

[0041] Energy saving: By reasonably distributing the torque currents Iq of the left and right motors, unnecessary energy consumption can be reduced, improving the energy efficiency of the mobility aid.

[0042] Preferably, in this embodiment, the torque current compensation value of the left motor 400 is based on the speed of the left driving wheel 200, and the torque current compensation value of the right motor 500 is based on the speed of the right driving wheel 300; when it is determined that the assistive vehicle turns left, the torque current Iq of the left motor 400 is decreased in proportion to the speed v of the left driving wheel 200, and the torque current Iq of the right motor 500 is increased in proportion to the speed v of the right driving wheel 300; when it is determined that the assistive vehicle turns right, the torque current Iq of the left motor 400 is increased in proportion to the speed v of the left driving wheel 200, and the torque current Iq of the right motor 500 is decreased in proportion to the speed v of the right driving wheel 300. Designed in this way, by linking the adjustment of the torque current Iq with the actual speed of the driving wheel, precise control of the turning behavior of the assistive vehicle is achieved. This method not only improves the controllability of the assistive vehicle but also enhances its stability and adaptability at different speeds and conditions.

[0043] Define that the torque currents input to the left motor 400 and the right motor 500 are the same as Iq, the speed of the left driving wheel 200 is vL, and the speed of the right driving wheel is vR; When it is determined that the assistive vehicle turns left, the torque current of the left driving wheel 200 is adjusted to IqL = Iq vL / vR, and the torque current of the right driving wheel is adjusted to IqR = Iq vR / vL; when it is determined that the assistive vehicle turns right, the torque current of the left driving wheel 200 is adjusted to IqL = Iq vL / vR, and the torque current of the right driving wheel is adjusted to IqR = Iq vR / vL. Designed in this way, by adjusting the torque current proportionally, the speed difference between the left and right driving wheels can adapt to the needs of turning. Since the adjustment of the torque current is based on the speed ratio and takes into account the actual speeds of both the left driving wheel 200 and the right driving wheel 300, this strategy can achieve a smoother and more natural turn, improving the controllability and stability of the assistive vehicle.

[0044] In addition, when the assistive vehicle is pushed in the first direction, the assist determination of the controller 800 is triggered, and the left motor 400 and the right motor 500 are controlled to input the same torque current Iq, providing a torque for the left driving wheel 200 and the right driving wheel 300 that is consistent with the first direction, so that the assistive vehicle is pushed in the first direction, and the speeds v of the left driving wheel 200 and the right driving wheel 300 are monitored in real time, and the torque current Iq is adjusted in real time according to the speed changes of the left driving wheel 200 and the right driving wheel 300. Designed in this way, for the forward or backward movement of the assistive vehicle, an adaptive assist operation can also be achieved without relying on additional sensors, so that the assistive vehicle can adaptively follow the user's walking speed.

[0045] Among them, the real-time adjustment of the torque current according to the speed changes of the left driving wheel 200 and the right driving wheel 300 includes: Obtain the acceleration a or deceleration -a of the walking aid in the first direction according to the speed changes of the left drive wheel 200 and the right drive wheel 300. The acceleration a indicates that the walking aid is being pushed forward with acceleration, and the deceleration -a indicates that the walking aid is being pushed forward with deceleration. If the walking aid is being pushed forward with acceleration, the torque currents Iq of the left motor 400 and the right motor 500 are compensated positively in proportion to the acceleration a. If the walking aid is being pushed forward with deceleration, the torque currents Iq of the left motor 400 and the right motor 500 are compensated negatively in proportion to the deceleration -a.

[0046] With such a design, the responsiveness of the walking aid can be improved, enabling it to adapt to the user's pushing requirements more quickly. Through precise torque current compensation, the walking aid can provide a smoother and more natural pushing feeling, reducing the user's pushing burden.

[0047] For example: When using the walking aid to accelerate in the first direction, the forward speed v of the two wheels starts to increase and maintains a certain acceleration a. Then the controller 800 immediately starts to compensate the torque currents Iq of the left motor 400 and the right motor 500 positively, and makes the compensated torque current Iq proportional to the acceleration a. That is, when the acceleration a increases, the positively compensated torque current Iq also increases to increase the torque and provide a fast assistance effect. When the walking aid decelerates in the first direction and maintains a certain deceleration -a, the torque current Iq compensated for the two wheels is compensated negatively, and the compensated torque current Iq is made proportional to the deceleration -a. That is, when the deceleration -a increases, the negatively compensated torque current Iq also increases to reduce the torque and make the walking aid slow down to follow the user's walking speed.

[0048] Finally, when the walking aid is pushed in the second direction (backward) during the process of being pushed in the first direction (forward), the torque currents Iq of the left motor 400 and the right motor 500 are negatively compensated in proportion to the deceleration -a until the assist torque in the first direction becomes zero; as the walking aid continues to be pushed in the second direction, the left motor 400 and the right motor 500 are controlled to input the same torque current Iq, providing an assist torque for the left drive wheel 200 and the right drive wheel 300 that is consistent with the second direction, so that the left drive wheel 200 and the right drive wheel 300 run at the same speed and acceleration in the second direction, and the speeds of the left drive wheel 200 and the right drive wheel 300 are monitored in real time, and the torque current is adjusted in real time according to the speed changes of the left drive wheel 200 and the right drive wheel 300. Specifically, reference can be made to the adjustment method of the torque current when the walking aid is pushed in the first direction, which will not be elaborated here. With such a design, when the walking aid changes from the first direction to the second direction, the controller 800 will first negatively compensate the torque currents of the left motor 400 and the right motor 500 according to the ratio of the deceleration -a until the assist torque in the first direction becomes zero, forming a deceleration effect. This compensation is to smoothly reduce the assist in the original direction when the pushing direction changes, so as to avoid discomfort to the rider caused by sudden changes in assist.

[0049] It can be understood that in other embodiments of the present invention, the first direction can also be the rear, and the second direction is the front.

[0050] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the content described in the drawings and the above specific implementation manner. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. Control method for a mobility scooter, the mobility scooter comprising: a vehicle body; a left drive wheel and a right drive wheel, spaced apart in the width direction at the rear side of the vehicle body; a left motor and a right motor, respectively connected to the left drive wheel and the right drive wheel to provide assist torque; a left driven wheel and a right driven wheel, spaced apart in the width direction at the front side of the vehicle body; characterized in that it further comprises: a controller that controls the left motor and the right motor based on field-oriented control, and the controller monitors the acceleration and speed of the left drive wheel and the right drive wheel through the detection signals of Hall sensors or encoders built in the left motor and the right motor; or, the controller monitors the acceleration and speed of the left drive wheel and the right drive wheel through the zero-crossing intervals of the back electromotive force of the three-phase voltage; The control method includes: The controller controls the left motor and the right motor to input the same torque current, keeps the left drive wheel and the right drive wheel running at the same speed and acceleration, and monitors the acceleration and speed of the left drive wheel and the right drive wheel in real time; When a speed difference and / or an acceleration difference occur between the left drive wheel and the right drive wheel, a turning determination of the controller is triggered; The controller compensates the torque current of the left motor and / or the right motor according to the turning determination result to provide turning assistance for the mobility scooter.

2. The control method for a mobility scooter according to claim 1, characterized in that when it is determined that the mobility scooter turns left, the torque current of the left motor is reduced and / or the torque current of the right motor is increased; when it is determined that the mobility scooter turns right, the torque current of the right motor is reduced and / or the torque current of the left motor is increased.

3. The control method of the walking aid vehicle according to claim 2, characterized in that The torque current compensation value of the left motor is based on the speed of the left drive wheel, and the torque current compensation value of the right motor is based on the speed of the right drive wheel; when it is determined that the mobility scooter turns left, the torque current of the left motor is reduced in direct proportion to the speed of the left drive wheel, and the torque current of the right motor is increased in direct proportion to the speed of the right drive wheel; when it is determined that the mobility scooter turns right, the torque current of the left motor is increased in direct proportion to the speed of the left drive wheel, and the torque current of the right motor is reduced in direct proportion to the speed of the right drive wheel.

4. The control method of the walking aid according to claim 2, wherein, Define that the left motor and the right motor input the same torque current as Iq, the speed of the left drive wheel as vL, and the speed of the right drive wheel as vR; When determining that the walking assist vehicle turns left, adjust the torque current IqL = Iq of the left drive wheel vL / vR, and adjust the torque current IqR = Iq of the right drive wheel vR / vL; When determining that the assisted vehicle turns right, adjust the torque current IqL of the left drive wheel = Iq vL / vR, and adjust the torque current IqR of the right drive wheel = Iq vR / vL.

5. The control method of the walking aid vehicle according to claim 1, characterized in that When the mobility scooter is pushed in the first direction, a boost determination of the controller is triggered, the left motor and the right motor are controlled to input the same torque current, a boost torque consistent with the first direction is provided for the left drive wheel and the right drive wheel, the speeds of the left drive wheel and the right drive wheel are monitored in real time, and the torque current is adjusted in real time according to the speed changes of the left drive wheel and the right drive wheel.

6. The control method of the walking aid vehicle according to claim 5, wherein Adjusting the torque current in real time according to the speed changes of the left drive wheel and the right drive wheel includes: obtaining the acceleration or deceleration of the mobility scooter in the first direction according to the speed changes of the left drive wheel and the right drive wheel, where acceleration indicates that the mobility scooter is being pushed forward with acceleration, and deceleration indicates that the mobility scooter is being pushed forward with deceleration; if the mobility scooter is being pushed forward with acceleration, the torque currents of the left motor and the right motor are positively compensated in direct proportion to the acceleration; if the mobility scooter is being pushed forward with deceleration, the torque currents of the left motor and the right motor are negatively compensated in direct proportion to the deceleration.

7. The control method of the walking aid vehicle according to claim 6, characterized in that, When the walking aid is pushed in the second direction opposite to the first direction during the forward push in the first direction, first compensate the torque currents of the left motor and the right motor negatively in proportion to the deceleration until the assist torque in the first direction becomes zero; as the walking aid continues to be pushed in the second direction, control the left motor and the right motor to input the same torque current, provide an assist torque for the left drive wheel and the right drive wheel that is consistent with the second direction, monitor the speeds of the left drive wheel and the right drive wheel in real time, and adjust the torque current in real time according to the speed changes of the left drive wheel and the right drive wheel.

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