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

Abstract

The invention belongs to the field of means of transport and discloses a high-precision speed-regulating front and rear self-balance one-wheel scooter. The scooter comprises a wheel, a hub motor, a pedal, a bracket, a telescopic connecting rod, a speed-regulating rotating handle, a driving module and a power module and also comprises a control module, a high-precision speed measurement module and an attitude measurement module. The speed of the one-wheel scooter is adjusted by rotating a right handle, the balance in the left-right direction is controlled by means of the human balancing capacity, and the balance control and the speed control in the front-rear direction are realized by driving the hub motor through the driving module according to comprehensive control amount obtained by superposing the attitude balance control amount and speed control amount. According to the speed measurement module, as a coaxial gear and a acceleration gear are additionally arranged, the speed measurement precision is greatly improved, the problem that the measurement precision of speed and position information is difficultly met when the scooter runs at a low speed is solved, and the high-precision front-rear direction attitude self-balance control and the front-rear direction speed control of the one-wheel scooter are realized.

Description

Self-balancing single wheel scooter before and after a kind of high accuracy speed governing

Technical field

The invention belongs to field of vehicles, particularly relate to self-balancing single wheel scooter before and after a kind of high accuracy speed governing.

Background technology

Wheelbarrow is as a kind of emerging walking-replacing tool, there is the advantages such as volume is little, cost is low, easy to use, along with the raising of Robotics application level, also more and more higher to the requirement of intelligent transportation, requirement for self-balancing wheelbarrow not only rests on posture balancing and controls, but needs high-precision stable speeds control.

Application number is the patent of invention " front and back are to self-balancing type electric motor car " of 200810179658.8, by the measurement to pitching inclination angle and angular speed on wheelbarrow fore-and-aft direction, compensation, carry out front and back posture balancing to wheelbarrow to control, but fail to control the speed of wheelbarrow.And as a kind of vehicles, wheelbarrow when practical application accurately speeds control be very most important, this just proposes very high requirement to precisely testing the speed of car body.

Usually the tachometric survey for electric motor car adopts Hall element to test the speed.Hall element is generally made up of Hall element and magnet steel.Hall is semiconductor magnetosensitive device, produces signal pulse when Hall element and magnet steel relative motion, detects the umber of pulse (frequency) that unit interval Hall exports, is multiplied by wheel circumference and can obtains speed (meter per second).According to number of magnet poles in magnetic rotary disk, the resolution ratio of sensor measurement rotating speed just can be determined.But due to number of magnetic poles and the quantitative limitation of Hall element number, the wheel umber of pulse obtained that often circles is limited, when rotating speed is lower, range rate error is comparatively large, is difficult to the requirement meeting speeds control.

We once applied for the patent of " a kind of Self-balance manned monocycle based on inertia balance wheel " by name in 2012, application number is 201210217335.X.In patent, lines of description travelling wheel coaxially connects drive motors, and road wheel speed measuring coder is coaxially connected with road wheel.First, the structural design that is coaxially connected of motor and wheel in use motor be subject to the external world and collide with and damage.In addition, speed measuring coder is directly coaxially connected with wheel, because certainty of measurement is directly subject to the impact of the resolution ratio of photoelectric pulse coder itself and the indexing accuracy of inner code-disc, and single wheel scooter is a kind of low-speed motion instrument, the pulse signal quantity that unit interval produces is limited, therefore, although this invention has speed controlling function, rate accuracy is difficult to the requirement meeting high precision velocity control.Although the resolution ratio improving encoder can reduce measure error, cost is multiplied with the increase of resolution ratio often, is very restricted in concrete use.

Summary of the invention

For the above-mentioned problems in the prior art, in order to the good front and back self-balancing ability of single wheel scooter can be realized, good speeds control can be realized under the prerequisite of low cost again, the invention provides self-balancing single wheel scooter before and after a kind of high accuracy speed governing.

The present invention relates to self-balancing single wheel scooter before and after a kind of high accuracy speed governing, the speed of scooter adjusts roughly by rotating right handgrip (in-built linear Hall speed-regulating part), the balance of left and right directions controls by the balanced capacity of people self, balance on the accurate control of speed and fore-and-aft direction is completed by electric control system, and the circuit composition frame chart of electric control system as shown in Figure 3.Attitude measurement module records angular acceleration and the angular velocity information of wheelbarrow respectively, feeds back to control module and obtains posture balancing controlled quentity controlled variable u _bal; The upper speed measurement module of installing of wheel-hub motor driven vehicle wheel measures the speed of a motor vehicle of scooter, feeds back to control module and obtains rate controlling amount u _v.By posture balancing controlled quentity controlled variable u _balwith rate controlling amount u _vcarry out additive fusion, obtain motor-driven Comprehensive Control amount u _d, by driver module drive hub motor, realize high-precision single wheel scooter fore-and-aft direction attitude self-balancing and control and speeds control.

The luffing angle that posture balancing controlling unit need record according to attitude measurement module and angular velocity information are to attitude pour angle compensation.Owing to inevitably there is noise signal in the attitude detection signal of wheelbarrow, produce departure while making integrator eliminate static error, therefore, PID removes integral element in controlling, and selects NONLINEAR PD algorithm to control.

Posture balancing controlled quentity controlled variable u _balobtained by following formula by NONLINEAR PD algorithm:

$u_{\mathrm{bal}}\left(t\right)={\mathrm{PD}}_{\mathrm{bal}}\left(\mathrm{\θ}\right)=K_P^{\mathrm{bal}}\left(\mathrm{\θ}\right)+K_D^{\mathrm{bal}}\left(\frac{\mathrm{d\θ}}{\mathrm{dt}}\right)$

Wherein, PD _bal(θ) be the nonlinear PD control device of posture balancing; for non-linear ratio's parameter; for non-linear differential parameter.

Rate controlling amount u _vpID positive feedback algorithm is adopted to obtain by following formula:

$u_v\left(t\right)={\mathrm{PID}}_v\left(e_v\right)=K_P^v{e}_v+K_I^v\∫e_v\mathrm{dt}+K_D^v\frac{{\mathrm{de}}_v}{\mathrm{dt}}$

Wherein, it is actual speed with desired speed v _ddifference; PID _v(e _v) be speed control; for proportional, for positive feedback, for regulating wheelbarrow gait of march; for integration item, for positive feedback, the displacement potential energy that accumulation displacement difference is formed, this displacement potential energy can not only release rate static difference, and when can also ensure that complex road surface (comprising ramp) is advanced, gait of march is steady, has made wheelbarrow possess to break through the ability of obstacle in addition; for differential term, for negative-feedback, for eliminating self-excitation and the vibration of system.

At wheelbarrow gait of march controller PID _v(e _v) in, active is proportional, is secondly integration item, therefore, and PID _v(e _v) be a positive feedback device.

In the control algolithm of wheelbarrow, act on the Comprehensive Control amount u of motor _dt () is by posture balancing controlled quentity controlled variable u _balwith gait of march controlled quentity controlled variable u _vbe formed by stacking by following formula:

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

At u _din (t), posture balancing controller PD _bal(θ) dominate, gait of march controller PID _v(e _v) take second place.The gait of march of wheelbarrow controls by its posture balancing control realization.In order to control rate, the gait of march controller PID of positive feedback _v(e _v) first indulge speed, cause attitude before and after wheelbarrow unbalance, thus cause active gesture stability PD _bal(θ) speed of possibility contradiction originally, is made control to change consistent control problem into attitude θ, the Comprehensive Control amount u namely after the unified superposition of wheelbarrow _dt () can make gait of march stably follow the tracks of desired speed v while control posture balancing _d.

Self-balancing single wheel scooter before and after a kind of high accuracy speed governing, comprising: wheel, wheel hub motor, pedal, pedal connecting axle, support, extensible link, speed control crank, control module, driver module and power module.It is characterized in that, also comprise: control module, speed measurement module and attitude measurement module.Wherein,

Described control module, in rack-mount groove, for generation of the Comprehensive Control amount u of motor _d(t).Its core controller is a dsp chip, comprises the capturing unit CAP_QEP of encoder pulse in acquisition speed measurement module, the speed analog signal that speed control crank exports is converted to the ADC unit of data signal, produces composite control signal u _dthe task manager EV unit of (t) (PWM pulse width modulated wave), the asynchronous serial communication interface unit of communicate with host computer in debug process (SCI agreement) and the synchronous serial interface unit with reception attitude measurement module communication (SPI protocol).

Described speed measurement module, is arranged on the right side of support in groove, for accurately measuring the rotating speed of motor.Comprise: in-line gears a, accelerating gear b, grating encoder and photoelectric encoder.In-line gears a is connected with wheel hub motor central axis, and in-line gears a and accelerating gear b grinding tooth, grating encoder is coaxially connected with accelerating gear b.During vehicle wheel rotation, drive in-line gears a coaxial rotating, in-line gears a drives grating encoder and accelerating gear b coaxial rotating by accelerating gear b, and incremental optical-electricity encoder exports pulse information and delivers to control module.

Incremental encoder utilizes photoelectricity transformation principle to export three prescription wave impulse A, B and C phases.A, B two group pulse phase difference 90 °, can judge direction of rotation easily; C phase square wave often turns and only has a pulse, locates for datum mark.

When adopting traditional technique in measuring position, in order to determine concrete phase place, zero pulse, as initial pulse, adopts simple notation system can obtain tested angular displacement by exporting pulse to encoder _mfor:

${\mathrm{\θ}}_M=\frac{360M}{\mathrm{KZ}}$

Wherein, Z is the resolution ratio of encoder, and namely often circle the pulse number produced; M is that pulse coder exports pulse sum; K is the Clock Multiplier Factor that encoder exports pulse.

By θ _mexpression formula known, certainty of measurement is directly subject to the impact of the resolution ratio of photoelectric pulse coder itself and the indexing accuracy of inner code-disc.Due to the restriction of manufacturing process and cost, be difficult to obtain very high resolution ratio, therefore, resolution ratio becomes the principal element affecting certainty of measurement, especially even more serious for the monocycle system impact that movement velocity is lower.

In order to improve the resolution ratio of photoelectric code disk, the present invention adds an in-line gears a be connected with wheel hub motor central axis in speed measurement module, the accelerating gear b engaging with in-line gears a with one, be coaxially connected with grating encoder, its structural representation as shown in Figure 4.Do not change this body structure of code-disc in advance under, the present invention makes the resolution ratio of photoelectric code disk bring up to a/b doubly (a, b are respectively the number of teeth of in-line gears a and accelerating gear b), makes rate accuracy also bring up to a/b times nearly.

Described attitude measurement module, be made up of accelerometer and gyroscope, in rack-mount groove, for measuring angular acceleration and the angular velocity information of wheelbarrow, and Real-time Feedback is to control module, obtain carrying out that balance needed for control, accurate angle and angular velocity information to scooter fore-and-aft direction (angle of pitch) after filtering with after computing.

The beneficial effect that the present invention has is:

Speed measurement module in the present invention, under the condition not increasing cost, substantially increase the certainty of measurement of speed and positional information, solve the problem that speed that wheelbarrow causes because of photoelectric code disk lack of resolution when low cruise and positional information certainty of measurement are difficult to meet the demands.The angular acceleration recorded in conjunction with attitude measurement module and angular velocity information, rate controlling amount and posture balancing controlled quentity controlled variable are carried out additive fusion and obtain motor-driven Comprehensive Control amount by control module, achieve single wheel scooter high-precision fore-and-aft direction attitude self-balancing and control and speeds control.

Accompanying drawing explanation

Fig. 1 is the frame for movement schematic diagram of wheelbarrow involved in the present invention;

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

Fig. 3 is the circuit composition frame chart of electric control system involved in the present invention;

Fig. 4 is the structural representation of velocity measuring device involved in the present invention.

In figure: 1 wheel, 2 pedals, 3 wheel hub motors, groove on the left of 4 supports, groove on the right side of 5 supports, groove on 6 supports, 7 extensible link, 8 handle connecting rods, 9 power modules, 10 velocity measuring devices, 11 driver modules, 12 control modules, 13 attitude measurement modules, 14 speed control cranks, 15 control handle, 16 in-line gears a, 17 accelerating gear b, 18 grating encoders, 19 incremental optical-electricity encoders.

Detailed description of the invention

Below in conjunction with the drawings and specific embodiments, the present invention is further illustrated.

Self-balancing single wheel scooter before and after a kind of high accuracy speed governing, its frame for movement schematic diagram as shown in Figure 1, the structural representation of electric control system as shown in Figure 2, the circuit composition frame chart of electric control system as shown in Figure 3, comprising: wheel (1), wheel hub motor (3), pedal (2), pedal connecting axle, support, extensible link (7), speed control crank (14), driver module (11), power module (9).The axle of support both sides axis hole and wheel hub motor (3) is screwed; Pedal (2) is connected by pedal shaft with lower end, support both sides axis hole; Extensible link (7) lower end is connected with groove on support (6) front end, and upper end is connected with handle connecting rod (8); Speed control crank (14) is enclosed within handle connecting rod (8) right side, and speed control crank (14) is a kind of linear speed regulation parts, is connected with control module (12); Handle connecting rod (8) left side handle (15) is equipped with starting switch, loudspeaker and brake; Power module (9) is placed in groove on the left of support (4); Driver module (11) is arranged in groove on the right side of support (5), and one end is connected with wheel hub motor (3), and middle through overcurrent protection, the other end is connected with control module (12), receives the control signal that control module (12) sends.It is characterized in that, also comprise control module (12), speed measurement module (10) and attitude measurement module (13).

Control module (12), in rack-mount groove (6), for generation of the Comprehensive Control amount u of motor _d(t).Control module (12) selects Nanjing Fourier Electronics Co., Ltd. HDSP-Core2812 core board, and the processor of this system adopts TI company's T MS320F2812DSP, and system is 5V direct current supply.

Speed measurement module (10), is arranged in groove on the right side of support (5), for accurately measuring the rotating speed of motor.Comprise: in-line gears a(16), accelerating gear b(17), grating encoder (18) and incremental optical-electricity encoder (19).In-line gears a(16) be connected with wheel hub motor (3) central axis, in-line gears a(16) and accelerating gear b(17) grinding tooth, grating encoder (18) and accelerating gear b(17) be coaxially connected.

Attitude measurement module (13), the ADIS16300 four-degree-of-freedom inertia measurement sensor selecting ADI company to produce, comprises single axis gyroscope and three axis accelerometer, in rack-mount groove (6), for measuring angular acceleration and the angular velocity signal of wheelbarrow.

Safe, durable in order to ensure that scooter uses, native system support, side channel and pedal material all adopt high-quality Steel material.The wheel hub motor that wheel hub motor (3) selects the electric motor car of Yongkang City Science and Technology Ltd.'s production for a long time supporting, rated voltage 48v, rated power 1000w.Driver module (11) is 1000w big power controller supporting with it.Power module (9) is made up of 48v and 5v chargeable lithium cell, and 48v lithium battery selects Wei to inspire confidence in standard lithium ion battery, nominal voltage: 48V, working range: 39V-54.6V, nominal capacity: 10Ah.Built-inly to overcharge, cross put, overcurrent and short-circuit protection and integrated electricity supervisory circuit.5v chargeable lithium cell is that controller is powered.

During use can bi-pedal on pedal, regulate hand length of connecting rod according to individual height.Both hands hold handle, and left hand opens starting switch, and adjustment car body, in vehicle body hanger, groove (6) is parallel to the ground, and namely the angle of pitch is close to zero degree.After system electrification, control module (12) initializes attitude measurement module (13) element.

Rotate and turn right upper speed control crank, require (desired speed v to scooter certain speed _d), control module (12), in conjunction with the velocity information obtained in real time in speed measurement module, obtains gait of march controlled quentity controlled variable u _v.By posture balancing controlled quentity controlled variable u _balwith rate controlling amount u _vsuperposition, by driver module (11) drive motors, finally reaches stable speed v in posture balancing _dtracing control.

Above embodiment is only for illustration of the present invention and unrestricted technical scheme described in the invention, and all do not depart from technical scheme and the improvement thereof of invention spirit and scope, all should be encompassed in the middle of right of the present invention.

Claims (4)

1. self-balancing single wheel scooter before and after a high accuracy speed governing, comprise: wheel (1), wheel hub motor (3), pedal (2), pedal connecting axle, support, extensible link (7), speed control crank (14), driver module (11), and power module (9); Characterized by further comprising: control module (12), speed measurement module (10) and attitude measurement module (13); Wherein,

Described control module (12), in rack-mount groove (6), for generation of the Comprehensive Control amount u of motor _d(t); Its core controller is a dsp chip, comprising: the capturing unit CAP_QEP of encoder pulse in acquisition speed measurement module, is converted to the ADC unit of data signal by the speed analog signal that speed control crank (14) exports, and produces composite control signal u _dthe task manager EV unit of (t) (PWM pulse width modulated wave), the asynchronous serial communication interface unit of communicate with host computer in debug process (SCI agreement) and the synchronous serial interface unit of (SPI protocol) that communicates with reception attitude measurement module (ADIS16300);

Described speed measurement module (10), is arranged in groove on the right side of support (5), for accurately measuring the rotating speed of motor; Comprise: in-line gears a (16), accelerating gear b (17), grating encoder (18) and incremental optical-electricity encoder (19); In-line gears a (16) is connected with wheel hub motor (3) central axis, in-line gears a (16) and accelerating gear b (17) grinding tooth, grating encoder (18) is coaxially connected with accelerating gear b (17); When wheel (1) rotates, drive in-line gears a (16) coaxial rotating, in-line gears a (16) drives grating encoder (18) and accelerating gear b (17) coaxial rotating by accelerating gear b (17), and incremental optical-electricity encoder (19) exports pulse information and delivers to control module (12);

Described attitude measurement module (13), be made up of accelerometer and gyroscope, in rack-mount groove (6), for measuring angular acceleration and the angular velocity information of wheelbarrow, and Real-time Feedback is to control module (12), obtain carrying out that balance needed for control, accurate angle and angular velocity information to scooter fore-and-aft direction (angle of pitch) after filtering with after computing.

2. self-balancing single wheel scooter before and after a kind of high accuracy speed governing according to claim 1, it is characterized in that, the speed of described single wheel scooter adjusts roughly by rotating right handgrip (in-built linear Hall speed-regulating part), the balance of left and right directions controls by the balanced capacity of human body self, balance on the accurate control of speed and fore-and-aft direction, the Comprehensive Control amount u obtained by control module (12) _dt () realizes through driver module (11) drive hub motor (3).

3. self-balancing single wheel scooter before and after a kind of high accuracy speed governing according to claim 1 and 2, is characterized in that, the Comprehensive Control amount u that described control module (12) obtains _dt () is by posture balancing controlled quentity controlled variable u _balwith gait of march controlled quentity controlled variable u _vbe formed by stacking by following formula:

u _D(t)＝u _bal(t)+u _v(t)

Posture balancing controlled quentity controlled variable u _balcan be obtained by following formula by NONLINEAR PD algorithm:

$u_{\mathrm{bal}}\left(t\right)={\mathrm{PD}}_{\mathrm{bal}}\left(\mathrm{\θ}\right)=K_P^{\mathrm{bal}}\left(\mathrm{\θ}\right)+K_D^{\mathrm{bal}}\left(\frac{\mathrm{d\θ}}{\mathrm{dt}}\right)$

Wherein, PD _bal(θ) be the nonlinear PD control device of posture balancing; for non-linear ratio's parameter; for non-linear differential parameter;

Rate controlling amount u _vpID positive feedback algorithm is adopted to obtain by following formula:

$u_v\left(t\right)={\mathrm{PID}}_v\left(e_v\right)=K_P^v{e}_v+K_I^v{\∫e}_v\mathrm{dt}+K_D^v\frac{{\mathrm{de}}_v}{\mathrm{dt}}$

Wherein, it is actual speed with desired speed v _ddifference; PID _v(e _v) be speed control; for proportional, for positive feedback, for regulating wheelbarrow gait of march; for integration item, for positive feedback, the displacement potential energy that accumulation displacement difference is formed, this displacement potential energy can not only release rate static difference, and when can also ensure that complex road surface (comprising ramp) is advanced, gait of march is steady, and wheelbarrow is possessed break through the ability of obstacle; for differential term, for negative-feedback, for eliminating self-excitation and the vibration of system;

At wheelbarrow gait of march controller PID _v(e _v) in, active is proportional, is secondly integration item, therefore, and PID _v(e _v) be a positive feedback controller.

4. self-balancing single wheel scooter before and after a kind of high accuracy speed governing according to claim 1, it is characterized in that, described speed measurement module makes the resolution ratio of photoelectric code disk bring up to a/b doubly, doubly, a, b are respectively the number of teeth of in-line gears a (16) and accelerating gear b (17) to make rate accuracy also bring up to a/b nearly.