CN111830992B - Force control method and device of wheeled robot and wheeled robot - Google Patents
Force control method and device of wheeled robot and wheeled robot Download PDFInfo
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- CN111830992B CN111830992B CN202010754582.8A CN202010754582A CN111830992B CN 111830992 B CN111830992 B CN 111830992B CN 202010754582 A CN202010754582 A CN 202010754582A CN 111830992 B CN111830992 B CN 111830992B
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- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0212—Control of position or course in two dimensions specially adapted to land vehicles with means for defining a desired trajectory
- G05D1/0223—Control of position or course in two dimensions specially adapted to land vehicles with means for defining a desired trajectory involving speed control of the vehicle
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0276—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle
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Abstract
The invention relates to the technical field of robots, in particular to a force control method and device of a wheeled robot and the wheeled robot. The force control device of the wheeled robot comprises a desired rotation speed generation part, a control part and a control part, wherein the desired rotation speed generation part is used for generating the desired rotation speed of wheels according to the desired speed of a vehicle body; a desired traction force generation section for generating a desired traction force of the wheel; a desired wheel torque generating section for generating a desired torque of the wheel based on the desired rotational speed and the desired traction force; a rotational speed error generation unit for generating a rotational speed error from the real-time rotational speed and the desired rotational speed; a traction error generation section for generating a traction error from the real-time traction and the desired traction; and a control law generation unit for generating a wheel force-speed hybrid control law for use in force tracking control or speed tracking control of the wheel, based on the traction error, the rotational speed error, and the desired torque.
Description
Technical Field
The invention relates to the technical field of robots, in particular to a force control method and device of a wheeled robot and the wheeled robot.
Background
For the control of the movement of the wheeled robot, the whole machine is usually taken as a controlled object, but for the multi-wheeled robot, the movement of different wheels may be different in the movement process, the internal forces between the different wheels may interfere with each other, the movement of each other is blocked, and the driving efficiency of the wheeled robot is reduced.
Disclosure of Invention
The invention aims at improving the control of the wheeled robot, reducing the interference among different wheels and improving the driving efficiency of the wheeled robot.
In order to solve the above problems, the present invention provides a force control device of a wheeled robot, including a rotation speed acquisition part for acquiring a real-time rotation speed of a wheel; a force acquisition section for acquiring a real-time traction force of the wheel; a desired rotation speed generation section for generating a desired rotation speed of the wheel from a desired speed of the vehicle body; a desired traction force generation section for generating a desired traction force of the wheel; a desired wheel torque generating section for generating a desired torque of the wheel based on the desired rotational speed and the desired traction force; a rotational speed error generation unit configured to generate a rotational speed error from the real-time rotational speed and the desired rotational speed; a traction error generation section for generating a traction error from the real-time traction and the desired traction; and a control law generation unit configured to generate a wheel force-speed hybrid control law for use in force tracking control or speed tracking control of the wheel, based on the traction force error, the rotational speed error, and the desired torque.
Optionally, the real-time rotational speed and the desired rotational speed are used for negative feedback adjustment of the wheel rotational speed.
Optionally, the real-time traction force and the desired traction force are used for negative feedback adjustment of the desired traction force of the wheel.
Optionally, the wheels are provided with a plurality of pairs, and the wheel force and speed hybrid control law is used for carrying out rotation speed tracking control on one pair of wheels and carrying out traction tracking control on the other wheels so as to realize speed control on the vehicle body, so that interaction blocking acting force between different wheels is minimized.
Optionally, the control law generating unit is further configured to determine whether to perform rotational speed tracking control on the wheel according to the rotational speed error combination matrix; the control law generating part is used for judging whether to carry out traction tracking control on the wheels according to the traction error combination matrix.
Optionally, the control law generating unit further comprises a switch matrix generating unit for generating an error combination matrix, and the control law generating unit further performs rotational speed tracking control or traction tracking control on the wheel according to the error combination matrix.
Optionally, the vehicle body speed control device further comprises a speed acquisition part for acquiring the real-time speed of the vehicle body; the real-time speed and the desired speed are used for negative feedback adjustment of the vehicle body speed.
Optionally, the force acquisition part is further configured to acquire a real-time normal force of the wheel, and further includes a force distribution generation part configured to generate a force distribution matrix according to the real-time traction force and the real-time normal force, and the expected traction force generation part is further configured to generate expected traction forces of different wheels according to the force distribution matrix.
Compared with the prior art, the force control device of the wheeled robot has the beneficial effects that:
the method comprises the steps of obtaining the real-time rotating speed and the real-time traction force of the wheels, generating the expected moment of the wheels according to the expected rotating speed and the expected traction force, generating a force-speed hybrid control law of the wheels through the rotating speed error, the traction force error and the expected moment, and tracking and controlling the force or the speed of the wheels through the force-speed hybrid control law, so that the force-speed hybrid control of the wheels of the wheeled robot is realized, the force control or the speed control switching of the control mode of the wheeled robot is facilitated, and the driving efficiency of the wheels is improved.
The invention respectively determines the force control law or the speed control law of the single wheel based on the single wheel, and performs force control on one pair of wheels of the wheeled robot and speed control on other wheels, thereby avoiding simultaneously performing force control or speed control on all wheels of the wheeled robot, and further reducing mutual obstruction among different wheels. Particularly, the stress condition of the wheels changes on soft ground, the forces of the wheels are tracked in real time, the tracking error caused by simple speed tracking is avoided to be larger and larger, and the force tracking error can be converged to zero by tracking the speeds of other wheels and correcting the track.
The invention also provides a force control method of the wheeled robot, comprising the following steps:
acquiring the real-time rotating speed and the real-time traction of the wheels; generating a desired rotational speed of the wheel according to a desired speed of the vehicle body; acquiring the expected traction force of the wheel;
generating a desired torque for the wheel based on the desired rotational speed and the desired traction;
generating a rotational speed error according to the real-time rotational speed and the expected rotational speed; generating a traction error according to the real-time traction and the expected traction;
and generating a wheel force-speed hybrid control law according to the traction force error, the rotating speed error and the expected moment, wherein the wheel force-speed hybrid control law is used for force-speed hybrid control of the wheels.
Optionally, the vehicle wheels have a plurality of pairs, and further comprises performing rotation speed tracking control on one pair of the vehicle wheels according to the wheel force-speed hybrid control law, and performing traction tracking control on the other vehicle wheels so as to realize speed control on the vehicle body, so that interaction blocking acting force between different vehicle wheels is minimized.
Optionally, the method further comprises the steps of determining a rotational speed error combination matrix, and judging whether to perform rotational speed tracking control on the wheels according to the rotational speed error combination matrix; and determining a traction error combination matrix, and judging whether traction tracking control is performed on the wheels according to the traction error combination matrix.
Optionally, the method further comprises the step of determining an error combination matrix, and performing rotational speed tracking control or traction tracking control on the wheels according to the error combination matrix.
Optionally, the method further comprises the steps of obtaining real-time normal force of the wheels, generating a force distribution matrix according to the real-time traction force and the real-time normal force, and generating expected traction forces of different wheels according to the force distribution matrix.
The force control method of the wheeled robot has the same beneficial effects as the force control device of the wheeled robot, and is not described in detail herein.
The invention also provides a wheeled robot, which comprises the force control device of any one of the wheeled robots.
The invention also provides a wheeled robot, which comprises the force control device of the wheeled robot.
The beneficial effects of the wheeled robot are the same as those of the force control method of the wheeled robot, and are not described in detail herein.
Drawings
Fig. 1 is a flowchart of a force control method of a wheeled robot according to an embodiment of the present invention;
FIG. 2 is a top view of a single wheel stress condition of a wheeled robot according to an embodiment of the present invention;
FIG. 3 is a schematic view of a force applied to a wheeled robot according to an embodiment of the present invention;
fig. 4 is an impedance control block diagram of a wheeled robot according to an embodiment of the present invention;
fig. 5 is a force control block diagram of a wheeled robot according to an embodiment of the present invention;
fig. 6 is a speed control block diagram of a wheeled robot according to an embodiment of the present invention;
FIG. 7 is a force and speed hybrid control block diagram of a wheeled robot according to an embodiment of the invention;
FIG. 8 is a control block diagram of an embodiment of the present invention with force control and kinematic models of all wheels combined;
fig. 9 is a system block diagram of a force control device of a wheeled robot according to an embodiment of the present invention;
fig. 10 is a system block diagram of a force control device of a wheeled robot according to another embodiment of the present invention.
Reference numerals illustrate:
1-wheels; 2-vehicle body; 12-expected wheel moment generating part, 101-rotating speed collecting part, 102-expected rotating speed generating part, 103-rotating speed error generating part, 104-rotating speed switch matrix generating part, 123-control law generating part, 201-speed collecting part, 202-force distribution generating part, 203-expected traction force generating part, 301-force collecting part, 302-traction force error generating part and 303-force switch matrix generating part.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
In the description of the present specification, the descriptions of the terms "embodiment," "one embodiment," and the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or embodiment is included in at least one embodiment or illustrated embodiment of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same examples or implementations. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or implementations.
An embodiment of the present invention provides a force control device of a wheeled robot, as shown in fig. 9 and 10, including a rotation speed acquisition portion 101 for acquiring a real-time rotation speed of a wheel 1A force acquisition unit 301 for acquiring real-time traction force of the wheel 1>A desired rotation speed generation unit 3 for generating a desired rotation speed v of the vehicle body 2 d Generating a desired rotational speed of the wheel 1A desired traction force generation unit 203 for generatingThe desired traction force of the wheel 1 +.>A desired wheel torque generating section 12 for generating a desired wheel torque according to the desired rotational speed +.>And the desired traction +.>Generating a desired torque T of said wheel 1 d The method comprises the steps of carrying out a first treatment on the surface of the A rotational speed error generation part 103 for generating a rotational speed error according to the real-time rotational speed +.>And the desired rotational speed +.>Generating a rotational speed error T v The method comprises the steps of carrying out a first treatment on the surface of the A traction error generating part 302 for generating a traction error according to the real-time traction +.>And the desired traction +.>Generating traction error T f The method comprises the steps of carrying out a first treatment on the surface of the A control law generating section 123 for generating a control law based on the traction force error T f Said rotational speed error T v And the desired moment T d A wheel-force-speed hybrid control law T for force tracking control or speed tracking control of the wheel 1 is generated.
As shown in fig. 9, the real-time rotational speedReal-time acquisition using a rotational speed sensor, said real-time traction +.>Post-acquisition processing with force sensors, where the desired rotational speed is based on a kinematic model of the wheeled mobile robot>The method comprises the following steps:
wherein, in combination with the slip ratio formula,
wherein S is slip, x e ＝[x e z e ] T Is the end effector position x r ＝[x r z r ] T Is a position in a stationary state and,a vector from the center of mass of the wheeled robot to the center of the ith wheel;
wherein the real-time rotation speedAnd the desired rotational speed +.>For negative feedback regulation of the rotational speed of said wheel 1. That is, the control device is at said real-time rotational speed +.>As feedback information, the real-time rotation speed +.>Deviation from said desired rotational speed +.>
The rotation speed error is as follows:
here, the rotation speedThe error generating part is a rotation speed tracking PI controller, wherein K is a rotation speed tracking PI controller Pv 、K pf The proportional and integral coefficients of the speed tracking PI controller, respectively.
Wherein the real-time traction forceAnd the desired traction +.>For negative feedback adjustment of the desired traction of said wheel 1. That is, the control device is +_ with said real-time traction force>As feedback information, continuously correcting said real-time traction +.>And the desired traction +.>Deviation between->
The traction error is as follows:
here, the traction error generation section is a traction tracking PI controller, where K Pf 、K If The proportional and integral coefficients of the speed tracking PI controller, respectively.
Based on the contact model and the wheel-ground mechanical model, a nonlinear torque feedforward is obtained,
wherein,anda diagonal coefficient matrix of a contact model of the wheel, F DPd And F Nd Is the real-time traction force F DP And real-time normal force F N Is a desired value of (2).Is a combination of intercept and wave terms caused by the wheel thorns of all driving wheels, +.>Is a matrix of rotational inertia of the wheel.
Therefore, the real-time rotating speed and the real-time traction force of the wheel 1 are obtained, the expected moment of the wheel is generated according to the expected rotating speed and the expected traction force, the force-speed hybrid control law of the wheel is generated through the rotating speed error, the traction force error and the expected moment, the force or the speed of the wheel is tracked and controlled through the force-speed hybrid control law, the force-speed hybrid control of the wheel of the wheeled robot is realized, and the control mode of the wheeled robot is conveniently switched.
In the embodiment of the invention, the wheels 1 are provided with a plurality of pairs, and the wheel force and speed hybrid control law is used for carrying out rotation speed tracking control on one pair of the wheels 1 and carrying out traction tracking control on the other wheels 1 so as to realize speed control on the vehicle body 2, so that interaction blocking acting force between different wheels 1 is minimized.
The invention respectively determines the force control law or the speed control law of the single wheel based on the single wheel, and performs force control on one pair of wheels of the wheeled robot and speed control on other wheels, thereby avoiding simultaneously performing force control or speed control on all wheels of the wheeled robot, and further reducing mutual obstruction among different wheels. Particularly, the stress condition of the wheels changes on soft ground, the forces of the wheels are tracked in real time, the tracking error caused by simple speed tracking is avoided to be larger and larger, and the force tracking error can be converged to zero by tracking the speeds of other wheels and correcting the track.
In an embodiment of the present invention, the force control device of the wheeled robot further includes a rotational speed switch matrix generation section 104 for generating a rotational speed error combination matrix I-S D The control law generating unit 123 further determines whether or not to perform rotational speed tracking control on the wheel 1 based on the rotational speed error combination matrix; also included is a force switch matrix generator 303 for generating a traction error combining matrix S D The control law generating unit 123 also determines whether or not to perform traction tracking control on the wheel 1 based on the traction error combination matrix.
For example, with a plurality of pairs of wheels 1, the selected pair being the ith wheel and the (i+1) th wheel, a decoupled mixing matrix can be designed as follows:
in the method, in the process of the invention,
then, the control law of the wheel decoupling force/speed hybrid control is as follows:
T＝(I-S D )T v +S D T f +T d
the advantage of this arrangement is that by the arrangement of the rotational speed switch matrix generation section and the force switch matrix generation section 303, a rotational speed error combination matrix for the wheel rotational speed tracking control and a traction force error combination matrix for the wheel force tracking control are generated, respectively, and the rotational speed tracking control and traction force tracking control of the wheel are realized by the two control systems, respectively.
In embodiments of the present invention, force control and wheel speed control may also be coupled. Optionally, a switch matrix generating part 23 is further included for generating an error combination matrix, and the control law generating part 123 further performs rotational speed tracking control or traction tracking control on the wheel 1 according to the error combination matrix.
Defining the coupling mixing matrix as:
wherein S is Ci ∈(0，1)(i＝1，2，...，n w ) Is the mixed relative coefficient of the ith round.
By combining force control and speed control with S C In combination, the control law of the wheel coupling force/speed hybrid control is expressed as follows:
T＝(I-S C )T v +S C T f +T d
the advantage of this arrangement is that by setting the error combination matrix, an error combination matrix for both wheel speed tracking control and wheel force tracking control is generated, while rotational speed tracking control or traction tracking control of the wheel is achieved.
In an embodiment of the present invention, the force acquisition part 301 is further configured to acquire a real-time normal force of the wheel 1, and further comprises a force distribution generating part 202 configured to generate a force distribution matrix according to the real-time traction force and the real-time normal force, and the desired traction force generating part 203 is further configured to generate desired traction forces of different wheels 1 according to the force distribution matrix.
Here, the determining the force distribution condition a of the wheel includes:
obtaining the normal force of the wheelThe normal force is obtained by a force sensor;
according to the normal forceDetermining the force distribution factor of said wheel>And->
Determining a force distribution condition of the wheel based on the force distribution factor and the normal force
Wherein,for the normal force of the ith wheel, +.>Is to be in combination with->Unit vectors in the same direction, +.>A vector from the center of mass of the wheeled robot to the center of the ith wheel;
thus, by setting the force distribution condition a, the desired interaction force F of the wheeled robot is determined d And determining interaction forces between different wheels and the vehicle body, so that the interaction forces between the different wheels and the vehicle body tend to be optimal, and the obstruction between the different wheels is reduced.
Wherein the force control device of the wheeled robot further comprises a speed acquisition part 201 for acquiring the real-time speed of the vehicle body 2; the real-time velocity v and the desired velocity v d For negative feedback regulation of the speed of the vehicle body 2. That is, the control device uses the real-time speed v as feedback information to continuously correct the real-time speed v and the expected speed v d Deviation v between d -v。
The present invention also provides a force control method of a wheeled robot, as shown in fig. 1, including:
step S1: acquiring the real-time rotating speed and the real-time traction of the wheel 1; generating a desired rotational speed of the wheel 1 from a desired speed of the vehicle body 2; acquiring a desired traction force of the wheel 1;
step S2: generating a desired torque of the wheel 1 according to the desired rotational speed and the desired traction;
step S3: generating a rotational speed error according to the real-time rotational speed and the expected rotational speed; generating a traction error according to the real-time traction and the expected traction;
step S4: and generating a wheel force-speed hybrid control law according to the traction force error, the rotating speed error and the expected moment, wherein the wheel force-speed hybrid control law is used for force-speed hybrid control of the wheels 1.
In an embodiment of the present invention, the method further comprises obtaining a real-time normal force of the wheel 1, generating a force distribution matrix according to the real-time traction force and the real-time normal force, and generating expected traction forces of different wheels 1 according to the force distribution matrix.
In the embodiment of the invention, the wheels 1 are provided with a plurality of pairs, and the method further comprises the steps of carrying out rotation speed tracking control on one pair of wheels 1 according to the wheel force and speed mixing control law and carrying out traction tracking control on the other wheels 1 so as to realize speed control on the vehicle body 2, so that interaction blocking acting force among different wheels 1 is minimized.
In the embodiment of the invention, the method further comprises the steps of determining a rotational speed error combination matrix, and judging whether to perform rotational speed tracking control on the wheel 1 according to the rotational speed error combination matrix; and determining a traction error combination matrix, and judging whether traction tracking control is performed on the wheel 1 according to the traction error combination matrix.
In an embodiment of the present invention, as shown in fig. 7 and 8, the method further includes determining an error combination matrix, and performing rotational speed tracking control or traction tracking control on the wheel 1 according to the error combination matrix.
Desired interaction force F of the wheel with the wheeled robot d Acquiring a current speed v and a desired speed v of the wheeled robot d Determining a force distribution condition A of different wheels; according to the current speed v, the expected speed v d And the force distribution stripPiece a determines the desired interaction force F d ，
Wherein,the acceleration is obtained in real time; m's' d For the desired inertia, K P 、 K I PI controller coefficients, a is the force distribution condition of the wheel.
As shown in fig. 4, in the impedance control method, the driving torque of the wheeled robot is:
wherein G is gravity, V is centrifugal force, V d The desired speed of the wheeled mobile robot is indicated,finger speed tracking error, M' d ,D d And K d The inertia M, damping D and rigidity K, T of the expected C are driving moment, I w For moment of inertia>In order for the angle of rotation to be a function of,
R d refers to the desired external force that is applied to the body,
moment of inertia I w ＝diag{I w1 I w2 … I wn } n×n ；
Rotation angle
As shown in connection with fig. 2 and 3, fig. 2 is a top view of the forces between the ith wheel and the vehicle body. Establishing a contact model with respect to normal force and tangential driving force:
F N ＝k(z e -z r )；
F N is the normal force of the wheel, k is the rigidity, mu is the friction coefficient, F T For the tangential driving force of the wheel,is equivalent mass of robot, x e ＝[x e z e ] T Is the end effector position x r ＝[x r z r ] T Is a position in a stationary state.
As shown in connection with fig. 2 and 3, a wheel-ground force model is built regarding normal force and tangential driving force:
F N ＝k′(z′ e -z r )；
wherein,
thereby, F can be determined N ＝k′(z′ e -z r )；
Wherein k is rigidity, k' is equivalent rigidity, r, b are respectively radius and width of the wheel, theta 1 And theta 2 Is the entrance angle and the exit angle, θ m Is the maximum stress angle, θ is θ 1 To theta 2 Any angle therebetween. k (k) c Andis a topographic characteristic parameter, +.>Is the internal friction angle of the soil, N is the linear subsidence coefficient of the soil, < ->Is the equivalent sinking amount of the wheel, z' e For equivalent normal displacement coefficient, μ' is equivalent friction coefficient, K is soil shear deformation modulus.
Combining slip ratio formulasWhere S is slip.
Can be determined to
In connection with what is shown in fig. 3, it can be determined that:
wherein,is in combination with->Unit vectors in the same direction, T i ,m wi ,I wi ,v i ,μ′ i Respectively the driving moment, mass, moment of inertia, linear velocity and friction angle, i F N , i F DP , i F T ,respectively, the positive stress of the ith wheel, the traction force of the hook and the traction forceForce and slip force.
Thus, a kinematic model of the wheeled robot can be determined:
wherein,
wherein (1)>The linear speed and the angular speed of the wheel respectively;
and can then determine
Wherein,
considering running in soft ground, V.fwdarw.0; thus (2)
Wherein F is i ＝ i F DP - i F R Acting force for the mass center of the single wheel pair body;
F R ＝A(V+G+R′)；
in combination with the wheel-ground mechanical model,wherein RC is the rolling resistance coefficient, +.>Is equivalent to the robot mass, I w Is the moment of inertia.
In the case of a single wheel of a vehicle,
based on the driving moment of the wheeled robot, the impedance control law of the single wheel is that
Wherein,representing the error value of the rotation angle, F i d Is expected to F i ，Representing the desired moment of inertia, damping and stiffness, respectively.
In S1, as shown in fig. 5, a control model concerning the desired interaction force is established in advance:
wherein,
the current speed of the wheeled robot may be obtained in real time, the desired speed may be modified in real time according to the wheeled robot, and the desired speed may be determined according to the desired interaction force of the wheels.
Here, the determining the force distribution condition a of the wheel includes:
obtaining the normal force of the wheelThe normal force is obtained by a force sensor;
according to the normal forceDetermining the force distribution factor of said wheel>And->
Determining a force distribution condition of the wheel based on the force distribution factor and the normal force
Wherein,for the normal force of the ith wheel, +.>Is to be in combination with->Unit vectors in the same direction, +.>A vector from the center of mass of the wheeled robot to the center of the ith wheel;
thereby the processing time of the product is reduced,by setting the force distribution condition A, the expected interaction force F of the wheeled robot is utilized d And determining interaction forces between different wheels and the vehicle body, so that the interaction forces between the different wheels and the vehicle body tend to be optimal, and the obstruction between the different wheels is reduced.
Based on the kinematic model of the wheeled mobile robot, the method can obtain
The impedance control function of the wheel can be obtained by the Lagrangian equation:
for a wheeled robot, the force control laws and kinematics models of all wheels may be combined, as shown below,
wherein,
wherein M' is the inertia of the wheeled robot, v d To a desired speed, I w d In order for the moment of inertia to be desired,representing the desired moment of inertia, damping and stiffness, respectively,/->Is in combination with->Unit vectors in the same direction, +.>For the traction force of the wheel,is the vector from the center of mass of the wheel-type robot to the center of the ith wheel.
When v approaches v d In the time-course of which the first and second contact surfaces,
the transfer function of the combined force control law and the kinematic model of all the wheels and the block diagram thereof are shown in fig. 8;
in an embodiment of the present invention, as shown in fig. 5, the determining of the force control law of the wheeled robot includes:
determining angular acceleration of the wheelAnd rolling resistance i F R Determining the current interaction force F of the wheel and the vehicle body i The method comprises the steps of carrying out a first treatment on the surface of the DeterminingDetermining the current interaction force F of the wheel and the vehicle body i Comprising the following steps:
obtaining the traction force F of the wheel DP Determining the resistance of the wheel to the body i F R ；
According to the traction force F of the wheel DP And the resistance of the wheel to the body i F R Determining the current interaction force F i ＝ i F DP - i F R ；
According to the current interaction force F i The normal force, the angular accelerationAnd the rolling resistance i F R Determining a current torque T of the wheel i ；
Wherein,
based on a PI controller, determining the force control law of the wheeled robot according to the current torque
Here, as shown in fig. 6, the desired trajectory q of the wheel d The determination of (2) comprises: obtaining the current traction force F of the wheel DP And a reference trajectory q of the wheel r The method comprises the steps of carrying out a first treatment on the surface of the Based on the desired interaction force, the current traction force F DP And a reference trajectory q of the wheel r Determining the desired trajectory q of the wheel d 。
The desired moment of inertia of the wheel is
The desired damping of the wheel is
The desired stiffness of the wheel is
Wherein,
by the laplace variation, it is possible to obtain:
wherein,j is the jacobian matrix of the current slip s (t), x r And (t) is a reference track of the wheeled robot.
Derived from unexpected variations in wheel slip due to incompatibility between the wheelsIt may be unreasonable to track this +.>The accuracy of the track tracking of the wheeled robot is reduced. However, if the desired force is tracked, the incompatibility can be eliminated, ideally,/->
Based on the contact model and the wheel-ground mechanical model, a nonlinear torque feedforward is obtained,
wherein,
anda diagonal coefficient matrix of a contact model of the wheel, F DPd And F Nd Is F DP And F N Is a desired value of (2).Is a combination of intercept and wave terms caused by the wheel thorns of all driving wheels, +.>Is a matrix of rotational inertia of the wheel.
Reference trajectory q of the wheel r The expected rotation speed of the wheels can be obtained in real time through an encoder, and the PI controller is used for tracking.
The invention also provides a wheeled robot, which comprises the force control device of any one of the wheeled robots. The beneficial effects of the wheeled robot are the same as those of the force control method of the wheeled robot, and are not described in detail herein.
Although the present disclosure is described above, the scope of protection of the present disclosure is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the scope of the invention.
Claims (13)
1. A force control device of a wheeled robot, characterized by comprising a rotational speed acquisition part (101) for acquiring a real-time rotational speed of a wheel (1); a force acquisition unit (301) for acquiring a real-time traction force of the wheel (1); a desired rotation speed generation unit (3) for generating a desired rotation speed of the wheel (1) from a desired speed of the vehicle body (2); a desired traction force generation unit (203) for generating a desired traction force of the wheel (1); a desired wheel torque generating section (12) for generating a desired torque of the wheel (1) from the desired rotational speed and the desired traction force; a rotational speed error generation unit (103) for generating a rotational speed error from the real-time rotational speed and the desired rotational speed; a traction error generation section (302) for generating a traction error from the real-time traction and the desired traction; a control law generation unit (123) for generating a wheel force-speed hybrid control law for force tracking control or speed tracking control of the wheel (1) on the basis of the traction force error, the rotational speed error, and the desired torque;
the wheels (1) are provided with a plurality of pairs, the wheel force and speed hybrid control law is used for carrying out rotation speed tracking control on one pair of the wheels (1) and carrying out traction tracking control on the other wheels (1) so as to realize speed control on the vehicle body (2) and minimize interaction blocking acting force among different wheels (1);
the real-time rotational speed of the wheel (1) is recorded asThe real-time traction of the wheel (1) is recorded +.>The desired speed of the vehicle body (2) is denoted v d The desired rotational speed of the wheel (1) is +.>The desired traction of the wheel (1) is noted +.>The desired moment of the wheel (1) is denoted as T d The rotational speed error is marked as T v The traction error is noted as T f The wheel force and speed hybrid control law is marked as T;
the desired rotational speedThe method comprises the following steps:
wherein, in combination with the slip ratio formula,
wherein S is slip, x e ＝[x e z e ] T Is the end effector position x r ＝[x r z r ] T Is a position in a stationary state and,a vector from the center of mass of the wheeled robot to the center of the ith wheel;
said rotational speed error T v The method comprises the following steps:
wherein K is Pv 、K pf The proportional coefficient and the integral coefficient of the speed tracking PI controller are respectively;
said traction force error T f The method comprises the following steps:
wherein K is Pf 、K If The proportional coefficient and the integral coefficient of the speed tracking PI controller are respectively;
the desired moment T d The method comprises the following steps:
wherein,anda diagonal coefficient matrix of a contact model of the wheel, F DPd And F Nd Is the real-time traction force F DP And real-time normal force F N Is a desired value of (2);Is a combination of intercept and wave terms caused by the wheel thorns of all driving wheels, +.>Is a wheel moment of inertia matrix;
the wheel force and speed hybrid control law T is as follows:
T＝(I-S D )T v +S D T f +T d ；
wherein S is D As a decoupled mixing matrix for the i-th round and the i+1-th round:
in the method, in the process of the invention,
the desired traction force-real-time normal force from said wheel (1), according to said real-time traction +.>And generating a force distribution matrix of the real-time normal force generation.
2. Force control device of a wheeled robot according to claim 1, characterized in that the real-time rotational speed and the desired rotational speed are used for negative feedback adjustment of the rotational speed of the wheel (1).
3. Force control device of a wheeled robot according to claim 1, characterized in that the real-time traction force and the desired traction force are used for negative feedback adjustment of the desired traction force of the wheel (1).
4. A force control device of a wheeled robot according to claim 3, further comprising a rotational speed switch matrix generation unit (104) for generating a rotational speed error combination matrix, said control law generation unit (123) further judging whether or not to perform rotational speed tracking control on said wheel (1) based on said rotational speed error combination matrix; the control law generating unit (123) further includes a force switch matrix generating unit (303) for generating a traction force error combination matrix, and the control law generating unit (123) further determines whether or not to perform traction force tracking control on the wheel (1) based on the traction force error combination matrix.
5. A force control device of a wheeled robot according to claim 3, further comprising a switch matrix generating section (23) for generating an error combination matrix, the control law generating section (123) further performing rotational speed tracking control or traction force tracking control on the wheel (1) based on the error combination matrix.
6. A force control device of a wheeled robot according to claim 3, further comprising a speed acquisition section (201) for acquiring a real-time speed of the vehicle body (2); the real-time speed and the desired speed are used for negative feedback regulation of the speed of the vehicle body (2).
7. The force control device of a wheeled robot according to claim 6, characterized in that the force acquisition part (301) is further adapted to acquire a real-time normal force of the wheel (1), and further comprising a force distribution generating part (202) adapted to generate a force distribution matrix from the real-time traction force and the real-time normal force, the desired traction force generating part (203) being further adapted to generate desired traction forces of different wheels (1) from the force distribution matrix.
8. A method of controlling force of a wheeled robot, comprising:
acquiring the real-time rotating speed and the real-time traction of the wheel (1); generating a desired rotational speed of the wheel (1) from a desired speed of the vehicle body (2); -obtaining a desired traction force of the wheel (1);
generating a desired torque of the wheel (1) from the desired rotational speed and the desired traction;
generating a rotational speed error according to the real-time rotational speed and the expected rotational speed; generating a traction error according to the real-time traction and the expected traction;
generating a wheel force-speed hybrid control law according to the traction error, the rotational speed error and the desired torque, wherein the wheel force-speed hybrid control law is used for force-speed hybrid control of the wheels (1);
the wheels (1) are provided with a plurality of pairs, the wheel force and speed hybrid control law is used for carrying out rotation speed tracking control on one pair of the wheels (1) and carrying out traction tracking control on the other wheels (1) so as to realize speed control on the vehicle body (2) and minimize interaction blocking acting force among different wheels (1);
the real-time rotational speed of the wheel (1) is recorded asThe real-time traction of the wheel (1) is recorded +.>The desired speed of the vehicle body (2) is denoted v d The desired rotational speed of the wheel (1) is +.>The desired traction of the wheel (1) is noted +.>The desired moment of the wheel (1) is denoted as T d The rotational speed error is marked as T v The traction error is noted as T f Said vehicleThe wheel force and speed mixed control law is marked as T;
the desired rotational speedThe method comprises the following steps:
wherein, in combination with the slip ratio formula,
wherein S is slip, x e ＝[x e z e ] T Is the end effector position x r ＝[x r z r ] T Is a position in a stationary state and,a vector from the center of mass of the wheeled robot to the center of the ith wheel;
said rotational speed error T v The method comprises the following steps:
wherein K is Pv 、K pf The proportional coefficient and the integral coefficient of the speed tracking PI controller are respectively;
said traction force error T f The method comprises the following steps:
wherein K is Pf 、K If The proportional coefficient and the integral coefficient of the speed tracking PI controller are respectively;
the desired moment T d The method comprises the following steps:
wherein,anda diagonal coefficient matrix of a contact model of the wheel, F DPd And F Nd Is the real-time traction force F DP And real-time normal force F N Is a desired value of (2);Is a combination of intercept and wave terms caused by the wheel thorns of all driving wheels, +.>Is a wheel moment of inertia matrix;
the wheel force and speed hybrid control law T is as follows:
T＝(I-S D )T v +S D T f +T d ；
wherein S is D As a decoupled mixing matrix for the i-th round and the i+1-th round:
in the method, in the process of the invention,
the desired traction force-real-time normal force from said wheel (1), according to said real-time traction +.>And generating a force distribution matrix of the real-time normal force generation.
9. The method of force control of a wheeled robot according to claim 8, wherein the wheels (1) have a plurality of pairs, further comprising performing rotational speed tracking control on one pair of the wheels (1) according to the wheel force-speed mixture control law, and performing traction tracking control on the remaining wheels (1) to achieve speed control of the vehicle body (2) so that a mutual obstructing force between the different wheels (1) is minimized.
10. The force control method of a wheeled robot according to claim 9, further comprising determining a rotational speed error combination matrix, and judging whether to perform rotational speed tracking control on the wheel (1) based on the rotational speed error combination matrix; and determining a traction error combination matrix, and judging whether traction tracking control is performed on the wheel (1) according to the traction error combination matrix.
11. The force control method of a wheeled robot according to claim 9, further comprising determining an error combination matrix, and performing rotational speed tracking control or traction force tracking control on the wheel (1) according to the error combination matrix.
12. The method of force control of a wheeled robot according to claim 9, further comprising obtaining real-time normal forces of the wheels (1), generating a force distribution matrix from the real-time traction forces and the real-time normal forces, generating desired traction forces of different wheels (1) from the force distribution matrix.
13. A wheeled robot comprising a force control device of a wheeled robot according to any one of claims 1-7.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008074337A (en) * | 2006-09-25 | 2008-04-03 | Toyota Motor Corp | Vehicle controller |
| CN101423028A (en) * | 2007-10-29 | 2009-05-06 | 福特环球技术公司 | Traction control for demonstrating skid turn |
| CN102501779A (en) * | 2011-10-31 | 2012-06-20 | 长城汽车股份有限公司 | Method for controlling traction of electric vehicle |
| CN107117073A (en) * | 2017-05-08 | 2017-09-01 | 电子科技大学 | A kind of four-wheel wheel hub method for controlling traction of electric vehicle |
| CN111158376A (en) * | 2020-01-14 | 2020-05-15 | 山东省人工智能研究院 | Rocker rocker arm type planet car trajectory tracking coordination control method in soft and rugged terrain |
-
2020
- 2020-07-31 CN CN202010754582.8A patent/CN111830992B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008074337A (en) * | 2006-09-25 | 2008-04-03 | Toyota Motor Corp | Vehicle controller |
| CN101423028A (en) * | 2007-10-29 | 2009-05-06 | 福特环球技术公司 | Traction control for demonstrating skid turn |
| CN102501779A (en) * | 2011-10-31 | 2012-06-20 | 长城汽车股份有限公司 | Method for controlling traction of electric vehicle |
| CN107117073A (en) * | 2017-05-08 | 2017-09-01 | 电子科技大学 | A kind of four-wheel wheel hub method for controlling traction of electric vehicle |
| CN111158376A (en) * | 2020-01-14 | 2020-05-15 | 山东省人工智能研究院 | Rocker rocker arm type planet car trajectory tracking coordination control method in soft and rugged terrain |
Non-Patent Citations (2)
| Title |
|---|
| 6×6滑动转向电驱动无人车运动控制;闫永宝;张豫南;颜南明;孙晓雨;;火力与指挥控制(第10期);107-110 * |
| 松软崎岖地形中星球车运动参数估计及协调跟踪控制;陈超;工程科技Ⅱ辑 航空航天科学与工程(第2020年第02期);全文 * |
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