CN110888444B

CN110888444B - Self-balancing running device and control method thereof

Info

Publication number: CN110888444B
Application number: CN201911227502.7A
Authority: CN
Inventors: 王帅; 张正友; 郑宇�; 来杰; 陈相羽; 杨思成; 赵龙飞
Original assignee: Tencent Technology Shenzhen Co Ltd
Current assignee: Tencent Technology Shenzhen Co Ltd
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2021-03-09
Anticipated expiration: 2039-12-04
Also published as: CN110888444A

Abstract

A self-balancing driving device and a control method thereof, a computer readable storage medium and a computing device are described. The self-balancing running gear comprises a frame body, a front wheel steering system, a rear wheel driving system, a sensor unit and a controller, wherein the controller is configured to execute control on the angular speed of the front rotating shaft driving device for driving the front rotating shaft to rotate based on the running gear related parameters sensed by the sensor so that the running gear keeps balance at a target inclination angle. The self-balancing running gear may further include a momentum wheel system, and the controller may be further configured to perform control of a moment at which the momentum wheel driving gear drives rotation of the momentum wheel so that the running gear is balanced at the target inclination angle.

Description

Self-balancing running device and control method thereof

Technical Field

The disclosure relates to the technical field of automatic control, in particular to a self-balancing running device and a control method thereof, a computer readable storage medium and a computing device.

Background

Running devices such as bicycles, motorcycles, two-wheeled robots, etc., which include front and rear wheels, are a type of running device common in daily life, and such running devices are typically under-actuated systems which are unstable under uncontrolled conditions. The self-balancing control of such travel devices has attracted a great deal of attention both theoretically and practically. However, the current control method is single, either static balance control or dynamic balance control, and the control effect of the running device is poor.

Disclosure of Invention

In view of the above, the present disclosure provides a self-balancing running device and a control method thereof, which is intended to overcome some or all of the above-mentioned disadvantages and other possible disadvantages.

According to a first aspect of the present disclosure, there is provided a self-balancing running device including: a frame body; a front wheel steering system including front wheels, a front hinge mounted to the front hinge and rotatable with respect to the front hinge, and a front hinge driving device mounted to the first end of the frame and rotatable with respect to the frame, the front hinge driving device being configured to adjust a direction of the front wheels by driving rotation of the front hinge; a rear wheel drive system including a rear wheel mounted to the second end of the frame body and rotatable relative to the frame body, and a rear wheel drive device configured to drive rotation of the rear wheel to drive the travel device to travel; a sensor unit configured to sense a travel device-related parameter including an inclination angle of the frame body, a rotation angle of the front spindle, and a speed at which the travel device travels; a controller configured to perform control such that the running devices are balanced at a target inclination angle based on the running device-related parameter, the control including control of an angular velocity at which the front spindle drive device drives the front spindle to rotate.

In some embodiments, the self-balancing driving device further comprises a momentum wheel system comprising a momentum wheel mounted to the frame and a momentum wheel driving device configured to drive the momentum wheel to rotate in a plane perpendicular to the plane of the frame.

In some embodiments, the running gear-related parameter further comprises a turning angle of the momentum wheel, and wherein the controlling further comprises controlling a torque at which the momentum wheel driving device drives the rotation of the momentum wheel.

In some embodiments, the controller is further configured to receive a target tilt angle comprising the rack.

In some embodiments, the controller is configured to: firstly, determining a control matrix K; the control is then performed according to the following equation:

wherein the content of the first and second substances,

，

wherein, T_rA moment for the momentum wheel drive means to drive the rotation of the momentum wheel,

the angular velocity of the front rotating shaft driven by the front rotating shaft driving device is theta, the inclination angle of the frame body is theta, phi is the rotation angle of the momentum wheel,

is the rotating angle of the front rotating shaft,

is a target state vector comprising a target inclination of the rack.

In some embodiments, the controller is configured to determine the control matrix K as:

where R represents a positive definite matrix, B represents an input matrix, and P is a solution of the following equation:

wherein Q represents another positive definite matrix,

wherein the content of the first and second substances,

，

，m₁mass of the self-balancing running gear other than the momentum wheel, m₂Is the mass of the momentum wheel, L₁Is the height of the center of gravity of the self-balancing running gear other than the momentum wheel, L₂Is the height of the center of gravity of the momentum wheel, I₁The moment of inertia of the self-balancing running device except the momentum wheel, L is the axial center distance between the front wheel and the rear wheel, h is the gravity center height of the self-balancing running device, V is the running speed of the running device, and g is the gravity acceleration.

In some embodiments, the input matrix B is:

wherein the content of the first and second substances,

，I₂d is the horizontal distance between the contact point of the front wheel and the ground and the gravity center of the self-balancing running device.

In some embodiments, when the rotational speed of the momentum wheel is zero, the input matrix B is:

wherein the content of the first and second substances,

and d is the horizontal distance between the contact point of the front wheel and the ground and the gravity center of the self-balancing running device.

wherein the content of the first and second substances,

，

wherein p is a lower corner mark of K, L is the distance between the axes of the front wheel and the rear wheel, V is the advancing speed of the self-balancing running device, g is the gravity acceleration, np is the polynomial times of Kp (V),

is the polynomial coefficient corresponding to the i-th order term in Kp (V).

In some embodiments, the polynomial coefficient is calculated by comparing Kp (V) to

Is determined by least squares fitting.

According to a second aspect of the present disclosure, there is provided a method for controlling a self-balancing running device, wherein the self-balancing running device includes: a frame body; a front wheel steering system including front wheels, a front hinge mounted to the front hinge and rotatable with respect to the front hinge, and a front hinge driving device mounted to the first end of the frame and rotatable with respect to the frame, the front hinge driving device being configured to adjust a direction of the front wheels by driving rotation of the front hinge; a rear wheel drive system including a rear wheel mounted to the second end of the frame body and rotatable relative to the frame body, and a rear wheel drive device configured to drive rotation of the rear wheel to drive the travel device to travel;

wherein the method comprises the following steps: acquiring parameters related to a running device, wherein the parameters related to the running device comprise the inclination angle of the frame body, the rotation angle of the front rotating shaft and the running speed of the running device; performing control such that the running gear is balanced at a target inclination angle based on the running gear-related parameter, the control including control of an angular velocity at which the front spindle drive drives the front spindle to rotate.

In some embodiments, the self-balancing running gear further comprises: a momentum wheel system comprising a momentum wheel mounted to the frame and a momentum wheel drive configured to drive the momentum wheel in a plane perpendicular to the plane of the frame of the running gear, and wherein the running gear related parameters further comprise the rotational angle of the momentum wheel and the control further comprises control of the moment at which the momentum wheel drive drives the rotation of the momentum wheel.

In some embodiments, performing control based on the travel device-related parameter includes: determining a control matrix K; the control is performed according to the following equation:

wherein the content of the first and second substances,

，

wherein Tr is a moment of rotation of the momentum wheel driven by the momentum wheel driving device,

is the rotating angle of the front rotating shaft,

is a target state vector comprising a target inclination of the rack.

According to a third aspect of the present disclosure, there is provided a computer readable storage medium having stored thereon computer readable instructions which, when executed on a processor, may cause the processor to perform any of the methods as described above.

According to a fourth aspect of the present disclosure, there is provided a computing device comprising a memory and a processor, the memory configured to store thereon computer readable instructions which, when executed on the processor, cause the processor to perform any of the methods as described above.

Through the technical scheme, the dynamic balance of the running device with better effect can be completed by depending on the centrifugal force effect and the gyroscopic effect generated by the rotation of the front rotating shaft, and the static balance of the running device and/or the dynamic balance of the auxiliary running device can be completed by depending on the restoring moment generated by the rotation of the momentum wheel, so that the dynamic and static mixed balance control of the self-balancing running device can be realized. In the technical scheme of the present disclosure, the momentum wheel, the front rotating shaft or the combination of the momentum wheel and the front rotating shaft can be applied at a proper time to realize the balance control with good effect under various traveling speeds (including when the traveling speed is zero).

These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter.

Drawings

Further details, features and advantages of the disclosure are disclosed in the following description of exemplary embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a schematic view of a self-balancing travel arrangement according to one embodiment of the present disclosure;

FIG. 2 shows a schematic view of a self-balancing traveling apparatus according to another embodiment of the present disclosure;

FIG. 3A illustrates a rear view of a self-balancing travel arrangement according to one embodiment of the present disclosure;

FIG. 3B illustrates a side view of a self-balancing travel apparatus according to one embodiment of the present disclosure;

FIG. 4 illustrates an example flow chart of a control method of a self-balancing traveling apparatus according to one embodiment of this disclosure;

FIG. 5 illustrates an example fit relationship of terms in a control matrix to Lg/V according to one embodiment of this disclosure;

6A-6D illustrate example simulation graphs when a control method according to an embodiment of the disclosure is applied at different speeds of a self-balancing running gear;

fig. 7 illustrates an example system that includes an example computing device that represents one or more systems and/or devices that may implement the various techniques described herein.

Detailed Description

The following description provides specific details for a thorough understanding and enabling description of various embodiments of the present disclosure. It will be understood by those skilled in the art that the present disclosure may be practiced without some of these details. In some instances, well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the disclosure. The terminology used in the present disclosure is to be understood in its broadest reasonable manner, even though it is being used in conjunction with a particular embodiment of the present disclosure.

First, some terms referred to in the embodiments of the present application are explained so that those skilled in the art can understand that:

1. balancing: the balance of the running device at a target inclination angle is defined, namely, under the condition that the running device is at any initial inclination angle within a certain range, under the control of the controller, the inclination angle of the running device can be converged at the target inclination angle along with time;

2. static balance: the balance of the self posture of the running device when the running speed of the running device is zero is referred to herein as static balance realized only by means of a momentum wheel;

3. dynamic balance: the balance of the self posture of the running device when the running speed of the running device is greater than zero is referred to as dynamic balance realized only by a front rotating shaft in the text;

4. dynamic and static mixing balance: as used herein, "dynamic and static hybrid balance" refers to the balance where both the momentum wheel and the front axle participate in control together;

5. centrifugal force: centrifugal force is a virtual force, which is an inertial embodiment, and makes a rotating object far away from the rotation center of the rotating object; in order to make the object do circular motion, the object needs to be subjected to a force pointing to the circle center, namely a centripetal force; when the object is not stressed enough to provide the centripetal force required by circular motion, the object looks like that the centrifugal force is greater than the centripetal force, and the object can move away from the center of a circle, and the phenomenon is called as a centrifugal phenomenon;

6. the gyroscopic effect is as follows: the moment of gravity on the supporting point generated by the spinning top rotating at high speed does not cause the spinning top to topple over, but to precess at a small angle. This is the gyroscopic effect;

7. a running device: reference herein is made to any device having two wheels and capable of being moved by rotation of the two wheels including, but not limited to, bicycles, motorcycles, two-wheeled balance cars, two-wheeled robots, and the like.

Fig. 1 shows a schematic view of a self-balancing running gear 100 according to one embodiment of the present disclosure. As shown in fig. 1, the self-balancing driving apparatus 100 includes a frame body 110, a front wheel steering system 120, a rear wheel drive system 130, a sensor unit 140, and a controller 150.

The front wheel steering system 120 may include front wheels 121, a front axle 122, and a front axle driving device 123. The front wheel 121 may be mounted to the front rotation shaft 122 and rotatable with respect to the front rotation shaft 122, and the front wheel 121 may be mounted to the front rotation shaft 122 by a front wheel shaft, as an example, which is sleeved on and rotatable around the front wheel shaft. The front rotary shaft 122 is mounted to a first end of the frame body 110 and is rotatable with respect to the frame body 110. The frame body is a main structure of a running device, such as a frame of a bicycle, a motorcycle and the like. The front hinge driving means 123 is configured to adjust the direction of the front wheels 121 by driving the rotation of the front hinge 122. When the running device runs, the direction of the front wheels is the running direction of the running device. As an example, the front rotating shaft 122 may be connected to the frame body 110 by a structure such as a bearing, wherein the front rotating shaft is journaled on a sleeve by a bearing and the sleeve is fixed to the frame body; the front rotary shaft driving device 123 can drive the front rotary shaft 122 to rotate in the bearing.

Rear wheel drive system 130 may include rear wheels 131 and a rear wheel drive 132. The rear wheel 131 is mounted to the second end of the frame body 110 and is rotatable with respect to the frame body 110, and the rear wheel driving device 132 is configured to drive the rotation of the rear wheel 131 to drive the traveling device 100 to travel. As an example, the rear wheel 132 may be mounted to the frame body 110 through a rear wheel shaft and may be rotated about the rear wheel shaft by the rear wheel driving device 132. The travel speed of the running gear can be determined by detecting the rotation speed of the rear wheel.

The sensor unit 140 is configured to sense travel device-related parameters including the inclination of the frame body 110, the rotation angle of the front hinge 122, and the speed at which the travel device 100 travels. It should be noted that the sensor unit may comprise one or more sensors or sensing components for sensing these parameters, which may be located anywhere in the running gear and parts of which may even be part of the structure of the running gear itself. One of the sensors or sensing components may be configured to sense one or more of these parameters. For example, the sensor unit 140 may be configured to obtain a rotation angle of the front rotating shaft by sensing rotation of the front rotating shaft (particularly, the front rotating shaft driving device), sense a speed at which the traveling device travels by sensing a rotation speed of the rear wheels, acquire data using an Inertial Measurement Unit (IMU) and determine the inclination angle of the frame body based on the acquired data, although this is not limitative. As another example, the sensor unit 140 may include various photoelectric sensors, radar sensors, and the like for sensing the speed of the traveling device. It should be noted that the sensed running gear-related parameter may be a parameter directly sensed by the sensor unit or a parameter converted from the directly sensed parameter. For example, the sensing of the rotation speed of the rear wheel 131 may be directly sensed, or may be obtained by sensing the rotation angle of the rear wheel 131 and performing differential calculation for time t; the sensing of the rotation angle of the front rotation shaft 122 may be directly sensed, or may be obtained by sensing the rotation angular velocity of the front rotation shaft 122 and performing integral calculation for time t.

The controller 150 is configured to perform control of the angular velocity at which the front hinge driving device 123 drives the front hinge 122 to rotate based on the running device-related parameter so that the running device 100 is balanced at the target inclination angle. Controller 150 may be located at any location on the self balancing stand, for example, it may be directly attached to a suitable location on the self balancing stand, such as on a frame or a front spindle. The controller may be, for example, a device or apparatus having data processing capabilities including a processor, microprocessor, programmable logic device, application specific integrated circuit, or the like. The target inclination angle may be set in the controller by default in advance, for example, the target inclination angle is set to 0 degrees (i.e., the rack is perpendicular to the ground). The controller may also include a receiver to receive target control data, such as a target tilt angle, a command to start or stop driving the running gear, etc., from other devices (e.g., a remote control, etc.). Of course, the receiver may be separate from the controller and configured to receive the target control data from another device (e.g., a remote controller, etc.) and then send the target control data to the controller. The receiver may be, for example, a wireless communication module or the like.

In some embodiments, as shown in fig. 1, the self-balancing running gear 100 may further include a momentum wheel system 160. The momentum wheel system 160 includes a momentum wheel 161 and a momentum wheel drive 162, the momentum wheel 161 being mounted to the frame 110, the momentum wheel drive 162 being configured to drive the momentum wheel 161 to rotate in a plane perpendicular to the plane of the frame 110 of the running gear. The plane of the frame body is generally parallel to the plane of rotation of the rear wheel, i.e. the plane of rotation of the momentum wheel is perpendicular to the plane of rotation of the rear wheel.

The mounting position of the momentum wheel system 160 may be adjustable, such as by a mounting structure comprising an adjustable lead screw or the like. As an example, the momentum wheel system 160 may be sleeved on the frame body through an adjustable lead screw 163, and the height of the momentum wheel from the ground may be adjusted by rotating the adjustable lead screw. By changing the installation position (including the vertical position and the horizontal position) of the momentum wheel system 160, the mass distribution of the self-balancing running device 100 can be changed, thereby changing the position of the center of gravity of the self-balancing running device 100, which can affect the effect of the balance control of the self-balancing running device 100.

As an example, fig. 1 illustrates a mounting position of the momentum wheel 161 and the momentum wheel drive 162 below the frame 110, and fig. 2 illustrates that the momentum wheel 161 and the momentum wheel drive 162 are mounted above the frame 110. It is apparent that the installation of fig. 2 increases the height of the center of gravity of the self-balancing running gear 100 compared to fig. 1. It should be noted that the momentum wheel 161 may have a momentum wheel axis and may be connected to the mounting structure by the momentum wheel axis. Illustratively, the momentum wheel drive 162 may drive the momentum wheel to rotate about the momentum wheel axis by driving the momentum wheel axis to rotate.

In the case where the self-balancing running device 100 includes the momentum wheel system 160, the running device-related parameter sensed by the sensor unit 140 may further include a rotation angle of the momentum wheel 161, and the controller is further configured to perform control of a moment at which the momentum wheel driving device 162 drives the momentum wheel 161 to rotate based on the running device-related parameter so that the running device 100 is balanced at a target inclination angle. In some embodiments, the sensor unit 140 may be configured to obtain the rotation angle of the momentum wheel by sensing the rotation of the momentum wheel (particularly, the momentum wheel motor).

It should be noted that the front axle drive 123, the rear wheel drive 132, and the momentum wheel drive 162 described herein may be any suitable drive, such as various motors, power take-offs, such as steering gears, or transmissions used in conjunction with power take-offs.

It will be understood that "mounting" or "connecting" one element or component to another element or component described herein can mean either directly mounting or connecting, or indirectly mounting or connecting, i.e., "mounting" or "connecting" via intermediate elements or components. Further, the components and structures shown in the drawings are merely schematic, and actually, the self-balancing traveling apparatus 100 may include other components, and some of the components shown may be omitted or replaced with other components having similar functions.

The control principle of the controller of the self-balancing traveling apparatus 100 will be described in detail with reference to the accompanying drawings. For convenience of description, the control principle will be described below by taking as an example a case where the self-balancing running gear includes the momentum wheel system 160.

First, a control model of the self-balancing running gear 100 is established.

Assuming that the self-balancing running gear is stationary and the front axle is not rotating (i.e. the front wheels and the rear wheels are in the same plane), fig. 3A shows a rear view of the running gear in this case and fig. 3B shows a side view of the running gear. Referring to fig. 3A, the height of the center of gravity of the self-balancing running gear excluding the momentum wheel is L₁The height of the center of gravity of the momentum wheel is L₂(ii) a Y represents a plane defined by the front wheel and the rear wheel of the self-balancing running device under the condition that the front rotating shaft does not rotate; the inclination angle of the frame body is theta, namely the included angle between the plane Y and the vertical direction. Referring to fig. 3B, point C is the center of gravity of the self-balancing running gear including the momentum wheel, and the height thereof is h; the distance between the contact point of the front wheel of the running device and the ground and the contact point of the rear wheel of the running device and the ground is L; the horizontal distance between the contact point of the front wheels of the running gear with the ground and the center of gravity C is d. In this context, m is used₁And m₂Masses of the self-balancing running gear other than the momentum wheel and the momentum wheel are respectively represented by I₁And I₂The moment inertia of the self-balancing running device except the moment wheel and the moment inertia of the moment wheel are represented, the rotation angle of the moment wheel is represented by phi, the rotation angle of the front rotating shaft is represented by delta, and the travelling speed of the self-balancing running device is represented by V. Further, an inertia product D = mdh is defined, where m is the mass of the self-balancing running gear, i.e., m = m₁+m₂. It should be understood that "height" of an object described herein refers to a height of the object described with respect to a horizontal plane when the self-balancing running gear is vertically placed on the horizontal plane.

Assuming that the self-balancing running gear is static and the front rotating shaft does not rotate, and only relying on the momentum wheel to keep balance, a Lagrange equation is written for the system:

wherein the content of the first and second substances,

is Lagrange's operator, is the difference between kinetic energy KE and potential energy PE of the self-balancing running gear, q_iGeneralized coordinates (here theta and phi),

is the total torque. In addition to this, the present invention is,

denotes q_iThe derivative with respect to time, hereinafter similarly formed quantities, should be interpreted in the same way. The kinetic energy KE and potential energy PE are calculated as follows:

，

thus, it is possible to prevent the occurrence of,

is composed of

。

Will be provided with

Substituting the Lagrange equation to obtain

。

If the traveling speed of the self-balancing traveling device is not zero, namely V >0, an equation representing the relation between the state of the self-balancing traveling device and each measured physical quantity can be obtained:

in which the application

Is linearized, T_rIs the moment that a driving device (such as a motor) under the condition of friction force drives the momentum wheel to rotate.

The above equation characterizing the relationship between the state of the self-balancing running gear and the physical quantity can be written in the form of a matrix and defines an output vector y:

it can be further written as a model representing the state-to-physical quantity relationship of the self-balancing running gear expressed in a state space (where the characteristics of the drive are not taken into account):

wherein x is a state vector, u is an input vector, a is a state matrix, B is an input matrix, C is an output matrix, and D is a feed forward matrix, which are respectively defined as follows:

wherein the content of the first and second substances,

,

。

when the speed of travel of the self-balancing running gear V =0, the front axle is not rotating, i.e. δ is 0, so the derivative of δ in the control input u

Is 0 so that the term related to the rotation angle of the front rotating shaft can be set to zero, and the above model can be degenerated to a model that realizes static balance of the self-balancing running gear by relying only on the momentum wheel, wherein:

when the momentum wheel rotates

When the momentum wheel is not involved in the control of the self-balancing running gear, i.e. T in the control input u_rDefault to 0 so that the term related to the momentum wheel rotation can be set to zero, the above model can be degenerated to a model that realizes dynamic balance of the self-balancing running gear by means of only the front rotary shaft, wherein:

。

in fact, above V =0 and

as can be seen by the expression of matrix A, B, C, D, the dimensions of the model may be reduced. Consequently, subsequent calculations with respect to the controller may be simpler for both special cases.

As an example, in the case of using a motor as a driving means for driving the momentum wheel to rotate, the motor characteristics may be taken into account in the modeling process to create a model containing motor parameters. Illustratively, the physical model of the motor driving the momentum wheel to rotate is as follows:

wherein, V_mIs the motor voltage, K_eIs the back-electromagnetic force of the motor,

as angular velocity of the motor, L_mAnd R_mRespectively, armature coil inductance and resistance, i is the current of the motor, Tm is the torque produced by the motor, K_tIs the motor torque constant, N_gIs the transmission ratio. Due to the fact that

L in the physical model of the motor can be ignored_mTerm, thereby T can be obtained_rExpression (c):

will T_rSubstituting the expression(s) of (a) into the model representing the relationship of the state of the self-balancing running gear and the physical quantity, which is derived above without taking into account the characteristics of the driving device, a model taking into account the characteristics of the driving device (here, the motor) may be obtained, wherein:

similarly, when the speed V =0 at which the self-balancing running gear travels, the front rotation shaft does not rotate, so that the term relating to the rotation angle of the front rotation shaft can be set to zero, the above model can be degenerated to a model that achieves static balance of the self-balancing running gear by relying only on momentum wheels, wherein:

when the momentum wheel rotates

In the meantime, the momentum wheel does not participate in the control of the self-balancing running device, so that items related to the rotation of the momentum wheel can be set to zero, and the above model can be degenerated into a model for realizing the dynamic balance of the self-balancing running device only by means of the front rotary shaft, wherein:

。

it should be noted that when the self-balancing running gear does not include a momentum wheel, a similar model can be built according to the modeling process described above, wherein

Wherein the content of the first and second substances,

,

。

then, the controller is designed based on the established model. The controller may be designed based on the established model that does not contain parameters regarding the driving apparatus, without considering the characteristics of the driving apparatus; alternatively, a model design controller containing motor parameters may also be established taking into account characteristics of the drive, such as the motor characteristics described above. The design approach is the same, and only the state matrix used, the input matrix, and the resulting input vector differ from model to model. The following description will be given taking as an example a model that does not include parameters relating to the driving device.

Here, the control target is to balance (i.e., stabilize or asymptotically stabilize) the controlled running device at the target inclination, in other words, to make it possible for the initial inclination of the running device at any initial inclination to gradually converge to the target inclination under the control of the controller. In theory, the target inclination angle may be any value, but in practice the target inclination angle may generally relate to the expected travel path of the self-balancing running gear. For example, when the self-balancing running gear runs in a straight line, the target inclination angle is typically 0; when the self-balancing ride requires a turn, the target inclination angle is typically not 0, but is, of course, typically a value less than 90 ° due to physical limitations. The target inclination may be a preset default target inclination, for example, which is built into the controller by default; alternatively, the target tilt angle may be transmitted to the controller of the self-balancing running gear by a controlling person through a remote control device (such as a dedicated remote controller, a smart phone on which a corresponding program is run, a computer, or the like); alternatively, the target inclination angle may be determined by other devices based on an expected travel route of the running device or the like and transmitted to the controller or determined by the controller itself based on such information.

To achieve such a control target, classical feedback control u = -Kx is applied, taking u = -K (x-x) in consideration of the target tilt angle₀) Of the form (1), wherein x₀Is a target state vector, which includes a target tilt angle. Exemplarily, x₀Can be defined as

Wherein, theta₀Is the target tilt angle. Since only x-x is used when considering the target state vector₀Instead of x, both are essentially equivalent, so in the following analysis, for the sake of brevity, the determination method of the control matrix K is explained for u = -Kx, it being understood that the conclusions drawn apply both to the case where the target inclination angle is 0 and to the case where the target inclination angle is not 0.

Substituting u = -Kx into

Can obtain

. The introduction loss function:

，

q, R is two positive definite matrixes, which can be optional theoretically, and in fact, Q, R values can be determined according to engineering experience. When the index of the loss function reaches the minimum, the control matrix K is

Where P is a solution of the Riccati (Riccati) equation as follows:

。

after solving the control matrix K, substituting u = -Kx or u = -K (x-x)₀) Wherein the former can be regarded as the latter x₀In the case of =0, the moment T at which the momentum wheel drive drives the momentum wheel to rotate can be obtained_rAnd the angular speed of the front rotating shaft driving device for driving the front rotating shaft to rotate

. In this way, the momentum wheel drive can be controlled to a torque T_rDriving the rotation of the momentum wheel and controlling the front rotary shaft driving device to rotate at an angular speed

And driving the rotation of the front rotating shaft to control the state vector to be stable at the target state vector, namely controlling the self-balancing running device to be balanced at the target inclination angle. It should be noted that in the case of using a motor as a driving means for driving the momentum wheel to rotate and considering the characteristics of the motor, the moment T at which the momentum wheel driving means drives the rotation of the momentum wheel can be controlled by controlling the input voltage of the motor_r。

Further, the computational effort to solve K each time by solving the ricalifting equation may be relatively large, especially for dynamic and static hybrid balance control. This may be detrimental to the implementation of real-time control. Thus, the present disclosure also provides a simple algorithm for controlling the matrix K for the case where the travel speed of the running gear is not zero, i.e., V > 0.

Since the input vector u is 2-dimensional and the state vector x is 4-dimensional, the control matrix K is 2 x 4-dimensional, which can be expressed as:

in the real-time control, the speed at which the travel device travels is varied, that is, V is varied, so that K may be K (V) in relation to the speed V at which the travel device travels at the present time:

through theoretical derivation, the fact that each item of K is in positive correlation with Lg/V is found, and therefore K can be calculated simply and conveniently in real-time control through predetermining the relationship between each item of K and Lg/V.

For example, several speeds of travel of the running gear may be selected

And calculating the corresponding K, i.e. the corresponding K, using the Riccati equation as described above, respectively₁(V)-K₈(V). Alternatively, K can be aligned using least squares₁(V)-K₈Fitting the relationship of (V) to Lg/V may attempt to describe the relationship between the two using a linear curve, a quadratic curve, a cubic curve, or even higher order curves, such that K is₁(V)-K₈The fit relationship of (V) to Lg/V can be expressed as:

where p is the lower corner mark of K, n_pIs K_p(iv) the degree of the polynomial of (V),

is K_pItem of degree i in (V)The corresponding polynomial coefficients.

Thus, K may be determined based on the control matrix K at several speeds of travel of the running gear before real-time control begins_p(V) fitting relationship to Lg/V, and then, in real-time control, K can be determined_p(V) fitting relationship with Lg/V to calculate the corresponding control matrix K based on the different speeds V of travel of the running gear in real time.

Fig. 4 shows an example flowchart of a control method of a self-balancing running gear according to an embodiment of the present disclosure.

At step 410, vehicle related parameters are obtained, including the inclination of the frame, the angle of rotation of the front hinge, and the speed at which the vehicle is traveling. In case the self-balancing running gear comprises a momentum wheel system, the running gear related parameter further comprises the turning angle of the momentum wheel.

Next, at step 420, control of the angular velocity at which the front spindle drive drives the rotation of the front spindle is performed based on the running gear-related parameter so that the running gear is balanced at the target inclination. In the case where the self-balancing running gear includes a momentum wheel system, control of the moment at which the momentum wheel driving gear drives the rotation of the momentum wheel is also performed based on the running gear-related parameter so that the running gear is balanced at the target inclination angle.

Therein, at step 421, a control matrix K is determined. In some embodiments, the control matrix K may be determined by directly solving the ricacies equation as described above, or may be determined by means of a predetermined fitting relationship of K (V) to Lg/V. It should be understood that the above method of determining the control matrix K by means of the predetermined fitting relationship of K (V) to Lg/V is only applicable to the case where the traveling speed of the running gear is not zero, and when the traveling speed of the running gear is zero, the control matrix K may be determined by directly solving the ricalifting equation based on the established model when V = 0.

At step 422, according to u = -K (x-x)₀) The control is executed. Wherein the content of the first and second substances,

，

is the rotating angle of the front rotating shaft,

is a target state vector comprising a target inclination of the rack. Alternatively, the target tilt angle may be a value equal to zero or greater than zero.

In the following, the control effect of the control method provided by the present disclosure is illustrated by a simulation example.

With reference to various physical parameters of the actual self-balancing running gear, the parameters in the model are given as (all using international standard units):

g = 9.81 of gravitational acceleration;

the mass m1 = 18.5 of the frame body of the running gear and the components except the momentum wheel;

the height of the momentum wheel center L1 = 0.2;

mass m2 = 2.3 of the momentum wheel;

the height L2 = 0.12 of the frame of the running gear;

radius r = 0.06 of the momentum wheel;

motor torque constant Kt = 20.6 × 0.001;

the back electromagnetic force Ke = 0.02 of the motor;

the motor transmission ratio Ng = 1;

motor armature coil resistance Rm = 0.21.

The simulation was conducted without considering the driving device characteristics, and the target tilt angle was assumed to be 0. Selecting a plurality of speeds V of the traveling device, calculating a control matrix K through the Riccati equation, and fitting the relation between each item in K (V) and Lg/V by using a least square method, wherein the fitting result is shown in FIG. 5, wherein in each frame, the abscissa is Lg/V, and the ordinate is K respectively₁(V)-K₈(V). Fitting the obtained K_pPolynomial coefficient corresponding to i-th order term in (V)

Carry-in K_p(V), K can be calculated in real time by sensing the speed V of the traveling device_p(V), thereby obtaining K in real time.

6A-6D illustrate example simulation diagrams of models of self-balancing ride at different speeds, where a control matrix K is determined based on speed V, with the substitution u = -K (x-x) according to the relationship of each of K (V) and Lg/V determined above with reference to FIG. 5₀) To obtain each control quantity (here, target inclination angle x)₀Assumed to be zero), the control quantities include momentum wheel torque and angular velocity of the front rotating shaft.

FIGS. 6A to 6D show simulation results when the traveling speed of the traveling device is 2m/s, 3m/s, 4m/s, and 5m/s, respectively. In each figure, simulation results of each output quantity and control quantity under the traveling speed of the corresponding running device are respectively shown, and curves a to d in each figure are simulation curves of each output quantity and respectively correspond to the inclination angle of the frame body, the angular speed corresponding to the inclination angle of the frame body, the angular speed of the momentum wheel and the rotating angle of the front rotating shaft; curves e and f are simulation curves of the control quantities, and correspond to moment of the momentum wheel and angular velocity of the front rotating shaft respectively.

As shown, at different speeds of travel of the running gear, the running gear remains stable over time, the inclination angle of the frame body approaches 0, and the momentum wheel speed also approaches 0, which meets the requirements and objectives of the controller design. Further, by comparing the simulation results at different speeds, it can be seen that the larger the speed at which the running device travels, the smaller the required input control amount, that is, the smaller the required momentum wheel torque, the smaller the angular velocity of the front rotating shaft. This means that the higher the traveling speed of the traveling device, the less the stress on the system hardware such as the drive device, and the more easily the system hardware is controlled. This is consistent with the experience in daily life, that is, the control difficulty of a two-wheel running device (e.g., a bicycle) is large when the running speed is small, and the control is relatively easy when the running speed is large.

When the simulation is performed in consideration of the characteristics of the driving device and the target inclination angle is assumed to be 0, the idea of the controller is not changed except that the control amount is replaced by the torque Tr of the motor and the voltage Vm of the motor, and similar simulation results can be obtained similarly.

Fig. 7 generally illustrates an example computing system 700 that includes an example computing device 710 that represents one or more systems and/or devices that may implement the various techniques described herein. The controller configured to control the self-balancing traveling apparatus described above may take the form of computing device 710. It may be a dedicated control device, such as a suitably programmed programmable logic controller, microprocessor, embedded processor, system on a chip, for example, attached to or arranged separately from the self-balancing running gear, or it may be a non-dedicated control device, such as a server of a service provider, a desktop computer, a notebook computer, a smart phone, and/or any other suitable computing device or computing system running the respective service.

The example computing device 710 as illustrated includes a processing system 711, one or more computer-readable media 712, and one or more I/O interfaces 713 communicatively coupled to each other. Although not shown, the computing device 710 may also include a system bus or other data and command transfer system that couples the various components to one another. A system bus can include any one or combination of different bus structures, such as a memory bus or memory controller, a peripheral bus, a universal serial bus, and/or a processor or local bus that utilizes any of a variety of bus architectures. Various other examples are also contemplated, such as control and data lines.

The processing system 711 represents functionality to perform one or more operations using hardware. Thus, the processing system 711 is illustrated as including hardware elements 714 that may be configured as processors, functional blocks, and so forth. This may include implementation in hardware as an application specific integrated circuit or other logic device formed using one or more semiconductors. Hardware element 714 is not limited by the material from which it is formed or the processing mechanism employed therein. For example, a processor may be comprised of semiconductor(s) and/or transistors (e.g., electronic Integrated Circuits (ICs)). In such a context, processor-executable instructions may be electronically-executable instructions.

The computer-readable medium 712 is illustrated as including a memory/storage 715. Memory/storage 715 represents memory/storage capacity associated with one or more computer-readable media. Memory/storage 715 may include volatile media (such as Random Access Memory (RAM)) and/or nonvolatile media (such as Read Only Memory (ROM), flash memory, optical disks, magnetic disks, and so forth). Memory/storage 715 may include fixed media (e.g., RAM, ROM, a fixed hard drive, etc.) as well as removable media (e.g., flash memory, a removable hard drive, an optical disk, and so forth). The computer-readable medium 712 may be configured in various other ways as further described below.

One or more input/output (I/O) interfaces 713 represent functionality to allow commands and data to be transmitted to and received from computing device 710. The I/O interface 713 may be implemented by any suitable communication interface and communication protocol.

The computing device 710 also includes a travel device control application 716. The travel device control application 716 may be stored as computer program instructions in the memory/storage device 715. Travel device control application 716 may, along with processing system 711, computer-readable medium 712, and I/O interface 713, implement the functionality of the controller described above that is configured to control a self-balancing travel device.

Various techniques may be described herein in the general context of software hardware elements or program modules. Generally, these modules include routines, programs, objects, elements, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The terms "module," "functionality," and "component" as used herein generally represent software, firmware, hardware, or a combination thereof. The features of the techniques described herein are platform-independent, meaning that the techniques may be implemented on a variety of computing platforms having a variety of processors.

An implementation of the described modules and techniques may be stored on or transmitted across some form of computer readable media. Computer readable media can include a variety of media that can be accessed by computing device 710. By way of example, and not limitation, computer-readable media may comprise "computer-readable storage media" and "computer-readable signal media".

"computer-readable storage medium" refers to a medium and/or device, and/or a tangible storage apparatus, capable of persistently storing information, as opposed to mere signal transmission, carrier wave, or signal per se. Accordingly, computer-readable storage media refers to non-signal bearing media. Computer-readable storage media include hardware such as volatile and nonvolatile, removable and non-removable media and/or storage devices implemented in a method or technology suitable for storage of information such as computer-readable instructions, data structures, program modules, logic elements/circuits or other data. Examples of computer readable storage media may include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical storage, hard disks, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other storage devices, tangible media, or an article of manufacture suitable for storing the desired information and accessible by a computer.

"computer-readable signal medium" refers to a signal-bearing medium configured to transmit instructions to hardware of computing device 710, such as via a network. Signal media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave, data signal or other transport mechanism. Signal media also includes any information delivery media. The term "modulated data signal" means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.

As previously described, hardware element 714 and computer-readable medium 712 represent instructions, modules, programmable device logic, and/or fixed device logic implemented in hardware form that may be used in some embodiments to implement at least some aspects of the techniques described herein. The hardware elements may include integrated circuits or systems-on-chips, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Complex Programmable Logic Devices (CPLDs), and other implementations in silicon or components of other hardware devices. In this context, a hardware element may serve as a processing device that performs program tasks defined by instructions, modules, and/or logic embodied by the hardware element, as well as a hardware device for storing instructions for execution, such as the computer-readable storage medium described previously.

Combinations of the foregoing may also be used to implement the various techniques and modules described herein. Thus, software, hardware, or program modules and other program modules may be implemented as one or more instructions and/or logic embodied on some form of computer-readable storage medium and/or by one or more hardware elements 714. The computing device 710 may be configured to implement particular instructions and/or functions corresponding to software and/or hardware modules. Thus, implementing a module as a module executable by computing device 710 as software may be implemented at least partially in hardware, for example, using computer-readable storage media of a processing system and/or hardware elements 714. The instructions and/or functions may be executable/operable by one or more articles of manufacture (e.g., one or more computing devices 710 and/or processing systems 711) to implement the techniques, modules, and examples described herein.

In various implementations, the computing device 710 may assume a variety of different configurations. Each of these configurations includes devices that may have generally different constructs and capabilities, and thus computing device 710 may be configured according to one or more of the different device classes. For example, the computing device 710 may be implemented as a computer-like device including a personal computer, a desktop computer, a multi-screen computer, a laptop computer, a netbook, and so forth. The computing device 710 may also be implemented as a mobile device-like device including mobile devices such as mobile phones, portable music players, portable gaming devices, tablet computers, multi-screen computers, and the like. Computing device 710 may also be implemented as a television-like device including a television, a set-top box, a game console, and so forth.

The techniques described herein may be supported by these various configurations of computing device 710 and are not limited to specific examples of the techniques described herein.

Computing device 710 may interact with client device 720, e.g., client device 720 may send target control data, such as the target tilt angle described above, to computing device 710. The client device 720 may be a dedicated remote control, joystick, etc. device or may be a non-dedicated device such as a smart phone, computer, etc. running the corresponding application.

Computing device 710 may interact with a "cloud" 730 as a platform for the system. In some embodiments, the functionality of computing device 710 may also be implemented in whole or in part on "cloud" 730 through the use of a distributed system, such as through platform 740 as described below.

Cloud 730 includes and/or is representative of a platform 740 for resources 742. The platform 740 abstracts underlying functionality of hardware (e.g., servers) and software resources of the cloud 730. Resources 742 may include applications and/or data that may be used when executing computer processes on servers remote from computing device 710. Resources 742 may also include services provided over the internet and/or over, for example, a cellular or Wi-Fi network.

The platform 740 may abstract resources and functionality to connect the computing device 710 with other computing devices. The platform 740 may also be used to abstract a hierarchy of resources to provide a corresponding level of hierarchy encountered for the requirements of the resources 742 implemented via the platform 740. Thus, in interconnected device embodiments, implementation of functions described herein may be distributed throughout the system 700. For example, the functionality may be implemented in part on the computing device 710 and by the platform 740 that abstracts the functionality of the cloud 730.

In the discussion herein, various embodiments are described. It is to be appreciated and understood that each embodiment described herein can be used alone or in association with one or more other embodiments described herein.

It should be understood that embodiments of the disclosure have been described with reference to different functional blocks for clarity. However, it will be apparent that the functionality of each functional module may be implemented in a single module, in multiple modules, or as part of other functional modules without departing from the disclosure. For example, functionality illustrated to be performed by a single module may be performed by multiple different modules. Thus, references to specific functional blocks are only to be seen as references to suitable blocks for providing the described functionality rather than indicative of a strict logical or physical structure or organization. Thus, the present disclosure may be implemented in a single module or may be physically and functionally distributed between different modules and circuits.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various devices, elements, or components, these devices, elements, or components should not be limited by these terms. These terms are only used to distinguish one device, element, or component from another device, element, or component.

Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the present disclosure is limited only by the accompanying claims. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. The order of features in the claims does not imply any specific order in which the features must be worked. Furthermore, in the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" or "an" does not exclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.

Claims

1. A self-balancing travel apparatus comprising:

a frame body;

a front wheel steering system including front wheels, a front hinge mounted to the front hinge and rotatable with respect to the front hinge, and a front hinge driving device mounted to the first end of the frame and rotatable with respect to the frame, the front hinge driving device being configured to adjust a direction of the front wheels by driving rotation of the front hinge;

a rear wheel drive system including a rear wheel mounted to the second end of the frame body and rotatable relative to the frame body, and a rear wheel drive device configured to drive rotation of the rear wheel to drive the travel device to travel;

a momentum wheel system comprising a momentum wheel mounted to the frame and a momentum wheel drive configured to drive the momentum wheel to rotate in a plane perpendicular to the plane of the frame;

a sensor unit configured to sense a driving device-related parameter including a tilt angle of the frame body, a rotation angle of the front rotation shaft, a speed at which the driving device travels, and a rotation angle of the momentum wheel;

a controller configured to perform control such that the running gear is balanced at a target inclination angle based on the running gear-related parameter, the control including control of an angular velocity at which the front spindle drive device drives the front spindle to rotate and control of a moment at which the momentum wheel drive device drives the momentum wheel to rotate;

wherein the controller is configured to:

the control matrix K is determined and,

the control is performed according to the following equation:

wherein the content of the first and second substances,

，

is the rotating angle of the front rotating shaft,

is a target state vector comprising a target inclination of the rack.

2. The self-balancing running gear of claim 1, wherein the controller is further configured to receive a target tilt angle including the frame body.

3. The self-balancing running device of claim 1, wherein the controller is configured to determine a control matrix K as:

wherein Q represents another positive definite matrix,

wherein the content of the first and second substances,

，

，m₁mass of the self-balancing running gear other than the momentum wheel, m₂Is the mass of the momentum wheel, L₁Is the height of the center of gravity of the self-balancing running gear other than the momentum wheel, L₂Is the height of the center of gravity of the momentum wheel, I₁The moment of inertia of the self-balancing running device except the momentum wheel, L is the axial center distance between the front wheel and the rear wheel, h is the gravity center height of the self-balancing running device, V is the running speed of the self-balancing running device, and g is the gravity acceleration.

4. The self-balancing running device according to claim 3, wherein the input matrix B is:

wherein the content of the first and second substances,

，I₂for rotation of the momentum wheelInertia, d is the horizontal distance between the contact point of the front wheel and the ground and the gravity center of the self-balancing running gear.

5. The self-balancing running gear of claim 3, wherein when the rotation speed of the momentum wheel is zero, the input matrix B is:

wherein the content of the first and second substances,

6. The self-balancing running arrangement of claim 1, wherein the controller is configured to determine a control matrix K as:

wherein the content of the first and second substances,

，

wherein p is a lower corner mark of K, L is an axle center distance between the front wheel and the rear wheel, V is a speed of the self-balancing running device, g is a gravitational acceleration, n is_pIs K_p(iv) the degree of the polynomial of (V),

is K_pAnd (V) the polynomial coefficient corresponding to the i-th order term.

7. The self-balancing driving device of claim 6, wherein the polynomial coefficient is calculated by pairing K_p(V) with

Is determined by least squares fitting.

8. A method for controlling a self-balancing running gear, wherein the self-balancing running gear comprises: a frame body; a front wheel steering system including front wheels, a front hinge mounted to the front hinge and rotatable with respect to the front hinge, and a front hinge driving device mounted to the first end of the frame and rotatable with respect to the frame, the front hinge driving device being configured to adjust a direction of the front wheels by driving rotation of the front hinge; a rear wheel drive system including a rear wheel mounted to the second end of the frame body and rotatable relative to the frame body, and a rear wheel drive device configured to drive rotation of the rear wheel to drive the travel device to travel; a momentum wheel system comprising a momentum wheel mounted to the frame and a momentum wheel drive configured to drive the momentum wheel to rotate in a plane perpendicular to the plane of the frame;

wherein the method comprises the following steps:

acquiring parameters related to a running device, wherein the parameters related to the running device comprise the inclination angle of the frame body, the rotating angle of the front rotating shaft, the running speed of the running device and the rotating angle of the momentum wheel;

performing control such that the running gear is balanced at a target inclination angle based on the running gear-related parameter, the control including control of an angular velocity at which the front spindle drive drives the front spindle to rotate and control of a moment at which the momentum wheel drive drives the momentum wheel to rotate;

wherein performing control based on the running device-related parameter includes:

determining a control matrix K;

the control is performed according to the following equation:

wherein the content of the first and second substances,

，

is the rotating angle of the front rotating shaft,

is a target state vector comprising a target inclination of the rack.

9. A computer readable storage medium having stored thereon computer readable instructions which, when executed on a processor, may cause the processor to execute the control method of claim 8.

10. A computing device comprising a memory and a processor, the memory configured to store thereon computer-readable instructions that, when executed on the processor, cause the processor to perform the control method of claim 8.