CN103183088B - High-precision speed-regulating front and rear self-balance one-wheel scooter - Google Patents

Abstract

The invention belongs to the field of vehicles, and discloses a high-precision speed-regulating front and rear self-balancing single-wheel scooter, including wheels, hub motors, pedals, brackets, scalable connecting rods, speed-regulating handles, drive modules and power modules. Including control module, high-precision speed measurement module and attitude measurement module. The speed of the unicycle scooter is adjusted by turning the right hand handle. The balance in the left and right directions is controlled by the balance ability of the human body itself. The drive module drives the hub motor to realize. The speed measurement module of the present invention greatly improves the speed measurement accuracy due to the addition of the coaxial gear and the acceleration gear, solves the problem that the measurement accuracy of the speed and position information of the unicycle is difficult to meet the requirements when the unicycle is running at low speed, and realizes the high precision of the unicycle. Front and rear attitude self-balancing control and speed control.

Description

A high-precision speed regulation front and rear self-balancing unicycle scooter

technical field

The invention belongs to the field of vehicles, in particular to a high-precision speed-regulating front and rear self-balancing unicycle.

Background technique

As a new means of transportation, the unicycle has the advantages of small size, low cost, and convenient use. With the improvement of the application level of robot technology, the requirements for intelligent transportation are getting higher and higher. The requirements for self-balancing unicycles are not only limited to In terms of attitude balance control, high-precision and stable speed control is required.

The invention patent with the application number of 200810179658.8 "front and rear self-balancing electric vehicle" controls the front and rear posture balance of the unicycle by measuring and compensating the pitch angle and angular velocity in the front and rear directions of the unicycle, but fails to control the speed of the unicycle . As a means of transportation, accurate speed control of the unicycle is very important in practical applications, which puts forward high requirements for accurate speed measurement of the vehicle body.

Usually, Hall sensors are used for speed measurement of electric vehicles. Hall sensors are generally composed of Hall elements and magnetic steel. Hall is a semiconductor magnetic sensitive device. When the Hall element and the magnetic steel move relative to each other, a signal pulse is generated, and the number of pulses (frequency) output by the Hall per unit time is detected, and multiplied by the circumference of the wheel to obtain the speed (m/s). According to the number of magnetic poles on the magnetic turntable, the resolution of the sensor to measure the rotational speed can be determined. However, due to the limitation of the number of magnetic poles and the number of Hall elements, the number of pulses obtained per wheel revolution is limited. When the speed is low, the error of speed measurement is large, and it is difficult to meet the requirements of speed control.

In 2012, we applied for a patent named "A self-balancing unicycle based on inertial balance wheel", the application number is 201210217335.X. The patent describes that the traveling wheel is coaxially connected to the drive motor, and the traveling wheel speed measuring encoder is coaxially connected with the traveling wheel. First of all, the structural design of the coaxial connection between the motor and the wheel is vulnerable to external bumps and damage to the motor during use. In addition, the speed measuring encoder is directly connected to the wheel coaxially, since the measurement accuracy is directly affected by the resolution of the photoelectric pulse encoder itself and the indexing accuracy of the internal code disc, and the unicycle is a low-speed movement tool, the unit time The number of generated pulse signals is limited. Therefore, although the invention has a speed control function, the speed measurement accuracy is difficult to meet the requirements of high-precision speed control. Although improving the resolution of the encoder can reduce the measurement error, the cost is often multiplied with the increase of the resolution, which is greatly limited in specific use.

Contents of the invention

Aiming at the above-mentioned problems existing in the prior art, in order to not only realize the good front and rear self-balancing ability of the unicycle scooter, but also realize good speed control under the premise of low cost, the present invention provides a high-precision speed regulation front and rear Self-balancing unicycle.

The invention relates to a high-precision speed-regulating front and rear self-balancing single-wheel scooter. The speed of the scooter is roughly adjusted by turning the right hand handle (with a built-in linear Hall speed regulating part), and the balance in the left and right directions is controlled by the balance ability of the person himself. The precise control and balance in the front and rear directions are completed by the electrical control system. The circuit diagram of the electrical control system is shown in Figure 3. The attitude measurement module measures the angular acceleration and angular velocity information of the unicycle respectively, and feeds back to the control module to obtain the attitude balance control value u _bal ; the speed measurement module installed on the wheel driven by the in-wheel motor measures the speed of the scooter, and feeds back to the control module to obtain the speed control value u _v . Superimposed and fused the attitude balance control quantity u _bal and the speed control quantity u _v to obtain the comprehensive control quantity u _D driven by the motor, and the hub motor is driven by the drive module to realize high-precision self-balancing control of the front and rear attitude and speed of the single-wheeled scooter control.

The attitude balance control link needs to compensate the attitude tilt angle according to the pitch angle and angular velocity information measured by the attitude measurement module. Because there is inevitably a noise signal in the attitude detection signal of the wheelbarrow, the integrator eliminates the static error and produces a control error at the same time. Therefore, the integral link is removed in the PID control, and the nonlinear PD algorithm is used for control.

The attitude balance control value u _bal is obtained by the nonlinear PD algorithm according to the following formula:

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bal</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; PD</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bal</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; P</span>}}^{\mathrm{<span\; class="notranslate">\; the\; bal</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}}^{\mathrm{<span\; class="notranslate">\; the\; bal</span>}}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d\&theta;</span>}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; )</span>$

Among them, PD _bal (θ) is the nonlinear PD controller of attitude balance; is a nonlinear scale parameter; is a nonlinear differential parameter.

The speed control value u _v is obtained by using the PID positive feedback algorithm as follows:

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; PIDs</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; P</span>}}^{\mathrm{<span\; class="notranslate">\; v</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}^{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; \&Integral;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}}^{\mathrm{<span\; class="notranslate">\; v</span>}}\frac{{\mathrm{<span\; class="notranslate">\; de</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}$

in, is the actual speed The difference with the desired speed v _D ; PID _v (e _v ) is the speed controller; is a proportional item, It is positive feedback, used to adjust the speed of the unicycle; is the integral item, It is positive feedback, the displacement potential energy formed by the cumulative displacement difference, this displacement potential energy can not only eliminate the static speed difference, but also ensure the stability of the speed when driving on complex road surfaces (including ramps), and also enable the unicycle to have the ability to break through obstacles; is the differential item, For negative feedback, it is used to eliminate self-excitation and oscillation of the system.

In PID _v (e _v ), the speed controller of the unicycle, the proportional term plays a leading role, followed by the integral term, therefore, PID _v (e _v ) is a positive feedback device.

In the control algorithm of the unicycle, the comprehensive control variable u _D (t) acting on the motor is superimposed by the attitude balance control variable u _bal and the travel speed control variable u _v as follows:

u _D (t)＝u _bal (t)+u _v (t)＝PD _bal (θ)+PID _v (e _v )

In u _D (t), the attitude balance controller PD _bal (θ) plays a dominant role, followed by the travel speed controller PID _v (e _v ). The speed control of the unicycle is realized through its posture balance control. In order to control the speed, the positive feedback travel speed controller PID _v (e _v ) indulges the speed first, which leads to the imbalance of the front and rear posture of the unicycle, which leads to the dominant attitude control PD _bal (θ), making the originally contradictory speed And attitude θ control is transformed into a consistent control problem, that is, the comprehensive control value u _D (t) of the wheelbarrow after uniform superposition can control the attitude balance and make the traveling speed stably track the desired speed v _D .

A high-precision speed-regulating front and rear self-balancing unicycle scooter, including: wheels, hub motors, pedals, pedal connecting shafts, brackets, telescopic connecting rods, speed-regulating handles, control modules, drive modules and power modules. It is characterized in that it also includes: a control module, a speed measurement module and an attitude measurement module. in,

The control module is installed in the upper groove of the bracket and is used to generate the comprehensive control value u _D (t) of the motor. Its core controller is a DSP chip, including the capture unit CAP_QEP that captures the encoder pulse in the speed measurement module, and the ADC unit that converts the output speed analog signal into a digital signal by the speed control to generate a comprehensive control signal u _D (t) (PWM pulse width modulated wave) event manager EV unit, an asynchronous serial communication interface unit communicating with the host computer (SCI protocol) during debugging, and a synchronous serial interface unit communicating with the receiving attitude measurement module (SPI protocol).

The speed measurement module is installed in the slot on the right side of the bracket, and is used to accurately measure the rotational speed of the motor. Including: coaxial gear a, acceleration gear b, grating code disc and photoelectric encoder. The coaxial gear a is coaxially connected with the central shaft of the hub motor, the coaxial gear a is meshed with the acceleration gear b, and the grating code disc is coaxially connected with the acceleration gear b. When the wheel rotates, it drives the coaxial gear a to rotate coaxially. The coaxial gear a drives the grating code disc and the accelerated gear b to rotate coaxially through the acceleration gear b. The incremental photoelectric encoder outputs pulse information and sends it to the control module.

The incremental encoder uses the principle of photoelectric conversion to output three groups of square wave pulses A, B and C phases. The phase difference between A and B two groups of pulses is 90°, which can easily judge the direction of rotation; the C-phase square wave has only one pulse per revolution, which is used for reference point positioning.

When the traditional method is used to detect the position, in order to determine the specific phase, the zero pulse is used as the initial pulse, and the measured angular displacement θ _M can be obtained by using a simple counting method for the encoder output pulse as:

${\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 360</span>}\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; KZ</span>}}$

Among them, Z is the resolution of the encoder, that is, the number of pulses generated per revolution; M is the total number of output pulses of the pulse encoder; K is the frequency multiplication coefficient of the output pulse of the encoder.

It can be seen from the expression of θ _M that the measurement accuracy is directly affected by the resolution of the photoelectric pulse encoder itself and the indexing accuracy of the internal code disc. Due to the limitations of the manufacturing process and cost, it is difficult to obtain a high resolution. Therefore, the resolution becomes the main factor affecting the measurement accuracy, especially for the unicycle system with a low moving speed.

In order to improve the resolution of the photoelectric code disc, the present invention adds a coaxial gear a coaxially connected with the central axis of the hub motor to the speed measurement module, and a coaxial gear a meshed with the coaxial gear a and coaxially connected with the grating code disc The schematic diagram of the acceleration gear b is shown in Figure 4. Without changing the structure of the code disc itself, the present invention increases the resolution of the photoelectric code disc to a/b times (a and b are the number of teeth of the coaxial gear a and the acceleration gear b respectively), and the accuracy of speed measurement is also improved to Almost a/b times.

The attitude measurement module is composed of an accelerometer and a gyroscope, installed in the upper groove of the bracket, and used to measure the angular acceleration and angular velocity information of the unicycle, and feed back to the control module in real time. Accurate angle and angular velocity information required for balance control in the direction (pitch angle).

The beneficial effects that the present invention has are:

The speed measurement module in the present invention greatly improves the measurement accuracy of speed and position information without increasing the cost, and solves the difficulty in the measurement accuracy of speed and position information caused by the insufficient resolution of the photoelectric code disc when the wheelbarrow is running at low speed. meet the requirements of the problem. Combined with the angular acceleration and angular velocity information measured by the attitude measurement module, the control module superimposes and fuses the speed control amount and the attitude balance control amount to obtain the comprehensive control amount of the motor drive, realizing the high-precision self-balancing control of the front and rear attitude of the unicycle and speed control.

Description of drawings

Fig. 1 is the schematic diagram of the mechanical structure of the wheelbarrow involved in the present invention;

Fig. 2 is the structural representation of electrical control system involved in the present invention;

Fig. 3 is the circuit composition block diagram of electrical control system involved in the present invention;

Fig. 4 is a schematic structural diagram of the speed measuring device involved in the present invention.

In the figure: 1 wheel, 2 pedal, 3 wheel hub motor, 4 left slot of bracket, 5 right slot of bracket, 6 upper slot of bracket, 7 retractable connecting rod, 8 turning handle connecting rod, 9 power module, 10 speed measuring device , 11 drive module, 12 control module, 13 attitude measurement module, 14 speed control handle, 15 control handle, 16 coaxial gear a, 17 acceleration gear b, 18 grating code disc, 19 incremental photoelectric encoder.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

A self-balancing single-wheel scooter before and after high-precision speed regulation, its mechanical structure schematic diagram is shown in Figure 1, the structural schematic diagram of the electrical control system is shown in Figure 2, and the circuit composition block diagram of the electrical control system is shown in Figure 3, including : Wheel (1), hub motor (3), pedal (2), pedal connecting shaft, bracket, telescopic link (7), speed control handle (14), drive module (11), power module (9) . The shaft holes on both sides of the bracket are fixed to the shaft of the hub motor (3) by screws; the pedal (2) is connected to the shaft holes on both sides of the bracket through the pedal shaft; the lower end of the telescopic connecting rod (7) is connected to the front end of the upper groove (6) of the bracket , the upper end is connected with the handle connecting rod (8); the speed regulating handle (14) is set on the right side of the rotating handle connecting rod (8), and the speed regulating handle (14) is a linear speed regulating component, which is connected with the control module ( 12) Connection; the turning handle connecting rod (8) on the left turning handle (15) is equipped with a start switch, horn and brake; the power module (9) is placed in the slot (4) on the left side of the bracket; the drive module (11) is installed on the In the slot (5) on the right side of the bracket, one end is connected to the hub motor (3), the middle passes through the current protection device, and the other end is connected to the control module (12) to receive the control signal from the control module (12). It is characterized in that it also includes a control module (12), a speed measurement module (10) and an attitude measurement module (13).

The control module (12) is installed in the upper slot (6) of the bracket, and is used to generate the comprehensive control quantity u _D (t) of the motor. The control module (12) selects HDSP-Core2812 core board of Nanjing Fourier Electronics Co., Ltd., the processor of the system adopts TMS320F2812DSP of TI Company, and the system is powered by 5V DC.

The speed measurement module (10) is installed in the slot (5) on the right side of the bracket, and is used to accurately measure the rotational speed of the motor. Including: coaxial gear a (16), acceleration gear b (17), grating code disc (18) and incremental photoelectric encoder (19). The coaxial gear a (16) is coaxially connected with the center shaft of the hub motor (3), the coaxial gear a (16) is meshed with the acceleration gear b (17), and the grating code disc (18) is coaxial with the acceleration gear b (17) connect.

The attitude measurement module (13) uses the ADIS16300 four-degree-of-freedom inertial measurement sensor produced by ADI, including a single-axis gyroscope and a three-axis accelerometer, and is installed in the upper slot (6) of the bracket to measure the angular acceleration and angular velocity of the unicycle Signal.

In order to ensure that the scooter is safe and durable to use, the brackets, side slots and pedals of this system are all made of high-quality steel materials. The hub motor (3) selects the hub motor matched with the electric vehicle produced by Yongkang Jiujiu Technology Co., Ltd., with a rated voltage of 48v and a rated power of 1000w. The drive module (11) is a matching 1000w high-power controller. The power module (9) is composed of 48v and 5v rechargeable lithium batteries. The 48v lithium battery is a Weifu standard lithium-ion battery, with a nominal voltage of 48V, an operating range of 39V-54.6V, and a nominal capacity of 10Ah. Built-in overcharge, overdischarge, overcurrent and short circuit protection and integrated power monitoring circuit. A 5v rechargeable lithium battery powers the controller.

When in use, both feet can be stepped on the pedals, and the length of the connecting rod of the handle can be adjusted according to the height of the individual. Hold the turning handle with both hands, turn on the start switch with the left hand, and adjust the car body. The groove (6) on the car body bracket is parallel to the ground, that is, the pitch angle is close to zero. After the system is powered on, the control module (12) initializes the elements of the attitude measurement module (13).

Turn the speed control handle on the right turn handle to give the scooter a certain speed requirement (desired speed v _D ), and the control module (12) combines the speed information obtained in real time from the speed measurement module to obtain the travel speed control value u _v . The attitude balance control quantity u _bal and the speed control quantity u _v are superimposed, and the motor is driven through the drive module (11), finally achieving a stable speed v _D tracking control in the attitude balance.

The above embodiments are only used to illustrate the present invention rather than limit the technical solutions described in the present invention. All technical solutions and their improvements that do not deviate from the spirit and scope of the invention should be covered by the claims of the present invention.

Claims (4)

1. A self-balancing single wheel car of riding instead of walk around high accuracy speed governing includes: the device comprises a wheel (1), a hub motor (3), a pedal (2), a pedal connecting shaft, a support, a telescopic connecting rod (7), a speed-regulating rotating handle (14), a driving module (11) and a power module (9); it is characterized by also comprising: the device comprises a control module (12), a speed measuring module (10) and an attitude measuring module (13); wherein,

the control module (12) is arranged in the bracket upper groove (6) and is used for generating comprehensive control quantity u of the motor_D(t); its core controller is a DSP chip, includes: encoding in acquisition speed measurement moduleA capture unit CAP _ QEP of the pulse of the device, an ADC unit for converting the speed analog signal output by the speed regulation converter (14) into a digital signal and generating an integrated control signal u_D(t) (PWM pulse width modulation wave) event manager EV unit, asynchronous serial communication interface unit communicating with upper computer (SCI protocol) and synchronous serial interface unit communicating with receiving attitude measurement module (ADIS16300) (SPI protocol) during debugging;

the speed measuring module (10) is arranged in the right side groove (5) of the bracket and is used for accurately measuring the rotating speed of the motor; the method comprises the following steps: a coaxial gear a (16), an accelerating gear b (17), a grating code disc (18) and an incremental photoelectric encoder (19); the coaxial gear a (16) is coaxially connected with a central shaft of the hub motor (3), the coaxial gear a (16) is meshed with the accelerating gear b (17), and the grating code disc (18) is coaxially connected with the accelerating gear b (17); when the wheel (1) rotates, the coaxial gear a (16) is driven to coaxially rotate, the coaxial gear a (16) drives the grating code disc (18) and the acceleration gear b (17) to coaxially rotate through the acceleration gear b (17), and the incremental photoelectric encoder (19) outputs pulse information and sends the pulse information to the control module (12);

the attitude measurement module (13) consists of an accelerometer and a gyroscope, is arranged in the upper groove (6) of the bracket and is used for measuring the angular acceleration and the angular velocity information of the monocycle, feeding the information back to the control module (12) in real time, and obtaining the accurate angle and the angular velocity information required by the balance control of the front and back directions (pitch angles) of the scooter after filtering and calculation processing.

2. The unicycle with high precision speed regulation and self-balancing in front and back of claim 1, wherein the speed of said unicycle is roughly regulated by turning right handle (with linear hall speed regulation inside), the balance in left and right direction is controlled by the balance ability of human body, the precision control of speed and the balance in front and back direction, the comprehensive control quantity u obtained by control module (12)_DAnd (t) is realized by driving the hub motor (3) through the driving module (11).

3. The high-precision speed-regulating front-rear self-balancing independent machine as claimed in claim 1 or 2The wheel-driven scooter is characterized in that the comprehensive control quantity u obtained by the control module (12)_D(t) controlling the quantity u by attitude balance_balAnd a traveling speed control amount u_vIs formed by superposing the following formulas:

u_D(t)＝u_bal(t)+u_v(t)

attitude balance control amount u_balThe following can be obtained by the nonlinear PD algorithm:

<math> <mrow> <msub> <mi>u</mi> <mi>bal</mi> </msub> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> <mo>=</mo> <msub> <mi>PD</mi> <mi>bal</mi> </msub> <mrow> <mo>(</mo> <mi>&theta;</mi> <mo>)</mo> </mrow> <mo>=</mo> <msubsup> <mi>K</mi> <mi>P</mi> <mi>bal</mi> </msubsup> <mrow> <mo>(</mo> <mi>&theta;</mi> <mo>)</mo> </mrow> <mo>+</mo> <msubsup> <mi>K</mi> <mi>D</mi> <mi>bal</mi> </msubsup> <mrow> <mo>(</mo> <mfrac> <mi>d&theta;</mi> <mi>dt</mi> </mfrac> <mo>)</mo> </mrow> </mrow> </math>

wherein PD is_bal(θ) is a pose-balanced nonlinear PD controller;is a non-linear scale parameter;is a nonlinear differential parameter;

speed control quantity u_vThe PID positive feedback algorithm is adopted and obtained according to the following formula:

<math> <mrow> <msub> <mi>u</mi> <mi>v</mi> </msub> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> <mo>=</mo> <msub> <mi>PID</mi> <mi>v</mi> </msub> <mrow> <mo>(</mo> <msub> <mi>e</mi> <mi>v</mi> </msub> <mo>)</mo> </mrow> <mo>=</mo> <msubsup> <mi>K</mi> <mi>P</mi> <mi>v</mi> </msubsup> <msub> <mi>e</mi> <mi>v</mi> </msub> <mo>+</mo> <msubsup> <mi>K</mi> <mi>I</mi> <mi>v</mi> </msubsup> <msub> <mrow> <mo>&Integral;</mo> <mi>e</mi> </mrow> <mi>v</mi> </msub> <mi>dt</mi> <mo>+</mo> <msubsup> <mi>K</mi> <mi>D</mi> <mi>v</mi> </msubsup> <mfrac> <msub> <mi>de</mi> <mi>v</mi> </msub> <mi>dt</mi> </mfrac> </mrow> </math>

wherein,is the actual speedWith desired speed v_DA difference of (d); PID_v(e_v) Is a speed controller;in the form of a proportional term, the ratio,the feedback is positive feedback and is used for adjusting the advancing speed of the monocycle;in order to be an integral term, the integral term,the displacement potential energy formed by accumulating the displacement difference for positive feedback can not only eliminate the speed static difference, but also ensure the stability of the advancing speed when the wheelbarrow advances on a complex road surface (including a ramp), and ensure that the wheelbarrow has the capability of breaking through obstacles；In order to be a differential term, the differential term,the negative feedback is used for eliminating self-excitation and oscillation of the system;

in the speed controller PID of advancing of wheel barrow_v(e_v) Of which proportional term is dominant and integral term is subordinate, and therefore PID_v(e_v) Is a positive feedback controller.

4. The self-balancing scooter before and after high-precision speed regulation according to claim 1, wherein the speed measurement module increases the resolution of the photoelectric code disc by a/b times and the speed measurement precision by nearly a/b times, wherein a and b are the number of teeth of the coaxial gear a (16) and the accelerating gear b (17), respectively.