JP2012126257A - Inverted mobile object and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate the posture of an occupant without using a special sensor, thereby achieving a favorable control.SOLUTION: An inverted mobile object 201 includes: a wheel 106; a platform 101; a unit 108 for estimating the posture of the occupant, which estimates the posture of the occupant in a vertical direction of the occupant 102 as an estimate value of the posture of the occupant based on an inclined angle of the platform 101 in the vertical direction, a rotation angle of the wheel 106, a rotary drive torque command of the wheel 106, a mass of the wheel 106, a radius of the wheel 106, an inertia moment about the rotation axis of the wheel 106, a mass of the occupant 202, and a distance between the platform 101 and the center of gravity of the occupant 102; and a controller 103 for controlling the rotary drive of the wheel 106 based on the inclined angle of the platform 101 in the vertical direction, the estimated value of the posture of the occupant thus estimated and obtained by the unit 108, and the rotation angle of the wheel 106.

Description

  The present invention relates to an inverted moving body and a control method thereof.

  In recent years, an inverted moving body has been developed that moves while a passenger is on board while maintaining an inverted state. Such an inverted moving body includes a platform on which a passenger is boarded, a wheel that moves the moving body while maintaining the platform in an inverted state, a motor that drives the wheel, and a control that outputs a motor current to the motor. A device including a detector, a detector for detecting a tilt angle of a platform, and a battery for supplying power to a controller or the like is well known (for example, Patent Document 1 and Patent Document 2).

  With reference to FIG. 6, the inverted moving body disclosed in Patent Document 1 will be briefly described. FIG. 6 is a schematic configuration diagram of the inverted moving body shown in Patent Document 1 (paragraph 0066 and FIG. 11). As shown in the figure, the inverted moving body 201 includes a platform 101 and wheels 106. The inverted moving body 201 moves while maintaining the inverted state of the platform 101 by the passenger 202 riding on the platform 101 and rotating by driving the wheels 106 with a motor (not shown). In the inverted mobile body 201, the occupant 202 changes the inclination angle of the platform 101, whereby the motor torque generated by the motor changes, and the direction obtained according to the inclination angle detected by a detector (not shown). And move according to speed.

  Patent Document 2 discloses an inverted moving body that enables stable inversion control even when the carriage installation surface is inclined or when there is a load fluctuation or the like.

Special table 2003-502002 gazette JP 2004-295430 A

  In the control of the conventional inverted moving body described above, the platform and the passenger are regarded as one body, and the control is performed based only on the inclination of the platform. That is, in the conventional control of the inverted moving body, the control in consideration of the occupant's posture itself is not performed.

  In practice, however, the passenger is not necessarily integral with the platform. For this reason, if the control is performed only based on the inclination of the platform, it may be difficult to ensure the safety of the passenger. For example, if the center of gravity of the occupant is positioned backward when the occupant tilts the platform forward, the inverted mobile body continues to accelerate forward according to the inclination of the platform, and the occupant It may be difficult to board safely by being pulled backward. Therefore, for example, in order to ensure the safety of the passenger even in such a case, it is strongly demanded that the posture of the passenger can be estimated from the viewpoint of safety.

  In addition, an unstable moving body that swings back and forth such as an inverted moving body is required to improve the ride quality so that the passenger can ride and move more comfortably. That is, from the viewpoint of riding comfort, it is strongly required to be able to estimate the posture of the passenger.

By the way, in order to measure (detect) the posture of the passenger, it is considered that a sensor such as a gyro sensor or an acceleration sensor may be disposed on the passenger.
However, adding such a sensor leads to an increase in cost, troublesome installation to the passenger, and a complicated wiring configuration.

  Therefore, the present invention solves the above-described problems, enables estimation of the occupant's posture without using a special sensor for measuring the occupant's posture, and realizes good control from the viewpoint of safety and riding comfort. An object of the present invention is to provide an inverted movable body and a control method thereof.

  The inverted mobile body according to the first aspect of the present invention includes a boarding board on which a passenger boards, a rotating body that moves the boarding board and has a circular cross section, an inclination angle of the boarding board with respect to a vertical direction, The rotational angle of the rotating body, the rotational drive torque command of the rotating body, the mass of the rotating body, the radius of the rotating body, the moment of inertia related to the rotating shaft of the rotating body, the mass of the passenger, A passenger posture estimator that estimates a passenger posture with respect to a vertical direction of the passenger as a passenger posture estimated value based on a distance between the boarding platform and the center of gravity of the passenger; A controller that controls rotational driving of the rotating body based on an inclination angle with respect to a direction, an estimated passenger posture estimated by the passenger attitude estimating device, and a rotational angle of the rotating body. It is.

  Accordingly, the posture of the passenger can be estimated without using a special sensor for measuring the posture of the passenger, and good control can be realized from the viewpoint of safety and riding comfort.

  Further, based on the estimated passenger posture estimated by the passenger posture estimator and the rotation angle of the rotating body, it is determined whether or not a condition that the passenger is highly likely to fall backward is satisfied. And the controller, when the controller determines that the passenger is highly likely to fall backward, the controller determines that the passenger falls. The control may be performed so as to avoid the backward fall of the vehicle. Thereby, it is possible to determine whether or not the condition that the passenger is likely to fall backward is satisfied, and when the backward fall condition is satisfied, control is performed so as to avoid the passenger falling backward. Is possible.

  Furthermore, the inclination angle of the boarding base with respect to the vertical direction, the rotation angle of the rotating body, the passenger posture estimated value estimated by the passenger posture estimator, the time differential value of the passenger posture, and the rotation Based on the mass of the body, the radius of the rotating body, the moment of inertia related to the rotation axis of the rotating body, the mass of the occupant, and the distance between the boarding platform and the center of gravity of the occupant, It further includes a backward fall avoidance torque command calculator for calculating a backward fall avoidance torque command, and the controller determines that the rear fall condition determination unit satisfies a condition that the passenger is likely to fall backward In such a case, control based on the backward fall avoidance torque command calculated by the backward fall avoidance torque command calculator may be performed. As a result, it is possible to calculate the backward fall avoidance torque command, and when the reverse fall condition is satisfied, it is possible to perform control based on the backward fall avoidance torque command.

  Further, an inclination angle of the boarding base with respect to a vertical direction, a rotation angle of the rotating body, a passenger posture estimated value estimated by the passenger posture estimator, a mass of the rotating body, and a radius of the rotating body, The time differential value of the passenger posture is calculated based on the moment of inertia related to the rotation axis of the rotating body, the mass of the passenger, and the distance between the boarding platform and the center of gravity of the passenger. A passenger posture time differential estimator for estimating the posture time differential estimated value is further provided, and the backward fall avoidance torque command computing unit includes an inclination angle with respect to a vertical direction of the boarding platform, a rotation angle of the rotating body, and the boarding A passenger posture estimated value estimated by a passenger posture estimator, a passenger posture time differential estimated value estimated by the passenger posture time differential estimator, a mass of the rotating body, a radius of the rotating body, and the rotation Inertia mode related to the rotation axis of the body Instruments and the mass of the occupant, the distance between the center of gravity of the passenger stand and the passenger, based on, may be calculated backward tipping avoidance torque command. Thereby, the passenger posture time derivative can be estimated, and based on this, it is possible to calculate a backward fall avoidance torque command.

Furthermore, the occupant posture estimator is θ ₁ : an inclination angle with respect to a vertical direction of the boarding platform,
θ ₂ : rotation angle of the rotator, r: radius of the rotator, l _c : distance between the boarding platform and the center of gravity of the occupant, m ₁ : mass of the occupant, m ₂ : rotation of the occupant The following equation (31) is used as the body mass, J ₂ : moment of inertia related to the rotation axis of the rotating body, T _m : rotational drive torque command of the rotating body, θ ₃ ^: the estimated occupant posture value. Thus, the estimated occupant posture value may be estimated.

Further, the backward tipping condition determiner uses the following equation (32) as θ ₂ : rotation angle of the rotating body, θ ₃ ^: the passenger posture estimated value, and the passenger falls backward. You may make it determine whether conditions with high possibility are satisfied.

Still further, the backward overturn avoidance torque command computing unit includes: θ ₁ : inclination angle of the boarding base with respect to a vertical direction, θ ₂ : rotation angle of the rotating body, θ ₃ ^: the estimated occupant posture, θ ₃ ^ ^(·) , Θ ₃ ^ ^(··) : time derivative estimated value of the passenger posture, r: radius of the rotating body, l _c : distance between the boarding platform and the center of gravity of the passenger, m ₁ : Mass of the occupant, m ₂ : Mass of the rotating body, J ₂ : Moment of inertia related to the rotating shaft of the rotating body, T _mp : The backward fall avoidance torque command, using the following equation (34): The backward fall avoidance torque command may be calculated.

Further, the occupant posture time differential estimator is configured such that θ ₁ : an inclination angle with respect to a vertical direction of the boarding base, θ ₂ : a rotation angle of the rotating body, θ ₃ ^: the occupant posture estimated value, r: the rotation Body radius, l _c : distance between the boarding platform and the center of gravity of the occupant, m ₁ : mass of the occupant, m ₂ : mass of the rotator, J ₂ : rotation axis of the rotator Moment of inertia, T _mp : The above-mentioned backward fall avoidance torque command, θ ₃ ^ ^(•) , θ ₃ ^ ^(••) : The above-mentioned occupant posture time differential estimated value, using the following equation (33), The passenger attitude time derivative estimated value may be estimated.

  Furthermore, you may make it the said rotary body be two wheels which oppose.

  An inverted moving body control method according to a second aspect of the present invention is a method for controlling an inverted moving body comprising: a boarding board on which a rider rides; and a rotating body having a circular cross section for moving the boarding board. The tilt angle of the boarding base with respect to the vertical direction, the rotation angle of the rotating body, the rotational drive torque command of the rotating body, the mass of the rotating body, the radius of the rotating body, and the rotating body Based on the moment of inertia relating to the rotation axis of the vehicle, the mass of the passenger, and the distance between the boarding platform and the center of gravity of the passenger, Based on the passenger posture estimation step to estimate as a value, the inclination angle of the boarding base with respect to the vertical direction, the passenger posture estimation value estimated by the passenger posture estimator, and the rotation angle of the rotating body, Control the rotational drive of the rotating body And your step, and has a.

  Accordingly, the posture of the passenger can be estimated without using a special sensor for measuring the posture of the passenger, and good control can be realized from the viewpoint of safety and riding comfort.

  According to the present invention, it is possible to provide an inverted moving body and a control method thereof that can estimate the posture of the occupant without using a special sensor and can realize good control.

FIG. 3 is a functional block diagram of the inverted mobile control device according to the first embodiment. 3 is a side view of the inverted moving body according to Embodiment 1. FIG. 6 is a graph showing a platform inclination angle and a passenger posture in a simulation result according to the first embodiment. 6 is a graph showing wheel speeds in a simulation result according to the first embodiment. 6 is a graph showing a torque command in the simulation result according to the first embodiment. It is a figure which shows the inverted type mobile body relevant to this invention.

Embodiment 1 FIG.
Embodiments of the present invention will be described below with reference to the drawings. In the following, in the description in the text, the symbols described before are used as necessary.

FIG. 2 shows a side view of the inverted moving body according to the first embodiment of the present invention.
As shown in the figure, the inverted moving body 201 includes a platform 101 on which a passenger 202 rides and a pair of wheels 106 that move the platform 101. The inverted moving body 201 moves when the passenger 202 gets on the platform 101. Hereinafter, the passenger 202 and the platform 101 may be collectively referred to as a load body.

  In FIG. 2, a pair of wheels 106 are arranged on the same axis, and each wheel 106 has a motor 104 (shown in FIG. 1 described later) that independently drives the pair of wheels 106 and a speed reducer 105 (see FIG. 2). 1)).

  The inverted moving body 201 includes a platform inclination angle detector 102 (shown in FIG. 1), a wheel angle detector 107 (shown in FIG. 1), a control device 100 (shown in FIG. 1), It has.

  The platform inclination angle detector 102 is installed at a portion where the platform 101 is rotatably connected to the axle. The wheel angle detector 107 is installed on the axle. Although details will be described later, a controller 103 (shown in FIG. 1) of the control device 100 includes a platform inclination angle detection value from the platform inclination angle detector 102, a wheel angle detection value from the wheel angle detector 107, Is used to control the rotation of the motor 104 so as to run while maintaining the inverted moving body 201 in an inverted state.

Here, the definition of each symbol shown in FIG. 2 will be described.
θ ₁ : Platform tilt angle (angle formed by the normal of platform 101 clockwise with respect to the vertical direction)
θ ₂ : Wheel angle (rotation angle of the wheel 106 in the vertical direction and clockwise)
θ ₃ : Passenger posture (the angle that the center line of the body passing through the center of gravity of the passenger 202 makes clockwise with the vertical direction)
r: wheel radius l _c : distance between the platform occupant center of gravity (the distance between the platform 101 and the center of gravity of the occupant 202, more specifically, the intersection of the center line of the body of the occupant 202 and the platform 101) And the center of gravity of the passenger 202)

  In addition, although illustration is abbreviate | omitted in FIG. 2, the inverted mobile body 201 is good also as a thing provided with the mobile body main body with which the platform 101 is provided. The pair of wheels 106 may be independently rotatable with respect to an axle fixed integrally with the moving body.

Next, with reference to FIG. 1, the structure of the control apparatus of the inverted moving body shown in FIG. 2 will be described.
FIG. 1 is a functional block diagram of the control device for an inverted moving body according to the present embodiment.
As shown in the figure, the control device 100 includes a controller 103, a passenger posture estimator 108, a rearward fall condition determination unit 109, a passenger posture time differential estimator 110, and a rearward fall avoidance torque command calculator 111. And. Since the platform 101, the platform inclination angle detector 102, the motor 104, the speed reducer 105, the wheel 106, and the wheel angle detector 107 have already been described with reference to FIG. Detailed description is omitted.

The occupant attitude estimator 108 includes a platform inclination angle detection value θ ₁ (hereinafter simply described using the same symbol as the platform inclination angle described with reference to FIG. 2) from the platform inclination angle detector 102 and wheels. The wheel angle detection value θ ₂ from the angle detector 107 (hereinafter simply described using the same symbol as the wheel angle described in FIG. 2) and the motor torque command T _m from the controller 103 are The occupant posture θ ₃ is input and is output as a passenger pose estimated value θ ₃ ^ (hereinafter, the symbol hat “^” indicates an estimated value). The details of the principle of passenger posture estimation by the passenger posture estimator 108 will be described later.

The rearward fall condition determination unit 109 receives the wheel angle detection value θ ₂ and the passenger posture estimation value θ ₃ ^ and determines whether or not the condition that the passenger 202 is highly likely to fall backward is satisfied. Then, the backward fall condition determination result is output. The details of the conditions under which the passenger 202 is likely to fall backward will be described later.

The passenger attitude time differential estimator 110 receives the platform tilt angle detection value θ ₁ , the wheel angle detection value θ ₂ , the passenger attitude estimation value θ ₃ ^, and the rearward fall condition determination result, and then falls backward If the condition is satisfied, the passenger posture time derivative is estimated and output as a passenger posture time derivative estimated value (θ ₃ ^ ^(•) , θ ₃ ^ ^(••) ) The dot “•” indicates time differentiation, “(•)” indicates first-order time differentiation, and “(••)” indicates second-order time differentiation.) Note that when the rearward fall condition is not satisfied, the passenger posture time derivative estimator 110 does nothing. Details of the principle of the passenger posture time differential estimation by the passenger posture time differential estimator 110 will be described later.

The backward tipping avoidance torque command calculator 111 includes a platform tilt angle detection value θ ₁ , a wheel angle detection value θ ₂ , a passenger posture estimated value θ ₃ ^, and a passenger posture time differential estimated value (θ ₃ ^ ^{(· )} , Θ ₃ ^ ^(··) ) and the rearward fall condition determination result are input, and when the rearward fall condition is satisfied, the backward fall avoidance torque command _Tmp is calculated and output. The rearward fall avoidance torque command calculator 111 does nothing when the rearward fall condition is not satisfied. The details of the principle of backward fall avoidance torque command calculation by the backward fall avoidance torque command calculator 111 will be described later.

Incidentally, a backward fall avoid torque command T _mp is required when executing a backward tipping avoidance operation of the rider 202 in the inverted type moving body 201, the target value of the motor torque T _m. The motor torque T _m is a torque transmitted to the axle of the wheel 106 after being decelerated by the speed reducer 105 (T _m represents a torque command that is a target value of the motor torque. motor torque command are both briefly described using the same symbols T _m.).

The controller 103 includes a platform tilt angle detection value theta _1, the wheel angle detection value theta _2, and a backward fall condition determination result, and a backward fall avoid torque command T _mp, is inputted, calculates a motor torque command T _m The motor current is output to the motor 104. The controller 103, when a backward fall condition is met, so that the motor torque T _m to follow the rear tipping avoid torque command T _mp, and outputs the motor current. The controller 103, when a backward fall condition is not satisfied, so as to maintain the inverted state of both of the occupant 202 and the inverted vehicle 201, motor torque command corresponding to the platform tilt angle detection value theta _{1 Tm} is calculated and motor current is output.

  The controller 103 aims to avoid the passenger 202 from falling backward from the normal inversion control (control that considers only the inclination angle of the platform 101) when the backward falling condition is satisfied. In order to switch to control that places importance on the posture of the passenger 202, it is also conceivable that the platform 101 comes into contact with the ground as a result of executing control for avoiding backward falling.

  For example, in a situation where the platform 101 is tilted forward and the occupant 202 is tilted later, the rearward fall condition is satisfied. As a result, the controller 103 controls the posture of the occupant 202 with importance. The platform 101 may tilt forward as it contacts the ground in front. Here, even if the platform 101 contacts the ground, further forward rotation of the platform 101 stops, and the speed at which the occupant 202 advances forward becomes zero. As a result, since the posture of the passenger 202 is directed upward, the passenger 202 can get off the platform 101 safely and easily. In other words, as a result of executing the control for avoiding the vehicle from falling backward, even if the platform 101 comes into contact with the ground, the passenger 202 can get off the inverted moving body 201 safely and easily.

  The control device 100 is realized as an electric / electronic / programmable electronic control system. For example, the control device 100 includes a CPU (Central Processing Unit) that performs arithmetic processing, a ROM (Read Only Memory) that stores arithmetic programs executed by the CPU, and a RAM (Random) that temporarily stores processing data and the like. The hardware configuration is centered on a microcomputer composed of (Access Memory). Further, each unit of the control device 100 may be realized by hardware such as an ASIC (Application Specific Integrated Circuit).

Subsequently, a specific operation principle of the above-described passenger posture estimator 108 and the like will be derived and will be described in detail.
First, an equation of motion for the inverted mobile body 201 and the passenger 202 is derived with reference to FIG. 2 described above. The kinetic energy K and potential energy U of the inverted moving body 201 and the passenger 202 are expressed using the following formulas (1) and (2), respectively.

Here, each symbol in the above formula is defined as follows.
m ₁ : Passenger mass m ₂ : Wheel mass J ₁ : Moment of inertia related to the axle of the load body including the passenger 202 and the platform 101 (hereinafter referred to as “load body inertia moment related to the axle”)
J ₂ : Moment of inertia related to the axle of the wheel 106 (hereinafter referred to as “wheel inertia of the wheel related to the axle”)
x ₁ : Horizontal position of the center of gravity of the passenger 202 (hereinafter referred to as “passenger center of gravity horizontal position”)
y ₁ : Vertical position of the center of gravity of the passenger 202 (hereinafter referred to as “passenger center of gravity vertical position”)
x ₂ : Horizontal position of the wheel 106 (hereinafter referred to as “wheel horizontal position”)

As shown in FIG. 2, the occupant center of gravity horizontal position x ₁ , the occupant center of gravity vertical position y ₁ , and the wheel horizontal position x ₂ are expressed using the following expressions (3), (4), and (5). Each is represented.

また、車軸に関する負荷体慣性モーメントＪ_１は以下の（６）を用いて表される。

The load body moment of inertia J ₁ about axle can be expressed using the following (6).

Here, each symbol in the above formula is defined as follows.
J ₁₀ : Moment of inertia of load body with respect to the center of gravity of the passenger 202 l: Distance between the axle and the center of gravity of the passenger 202

  By substituting Equation (3) to Equation (6) described above into Equation (1) and Equation (2), the following Equation (7) and Equation (8) are obtained, respectively.

  The equations of motion of the inverted mobile body 201 and the occupant 202 are expressed using the following equations (9) to (11) using Lagrangian L = K−U. In addition, d shows a disturbance torque.

  By substituting Equation (7) and Equation (8) described above into Equation (9) to Equation (11), the following equations of motion (12) to Equation (14) are obtained.

Next, the operation principle of the passenger posture estimator 108 will be described. Hereinafter, an equation used for passenger posture estimation is derived from the above-described equation of motion.
First, the equation (13) in the above equation of motion is rewritten as shown in the following equation (15).

When the occupant 202 gets on the inverted mobile body 201 and starts its operation, the platform inclination angle θ ₁ , the wheel angle θ ₂ , the occupant attitude θ _3, and their respective time differential values are all 0 [ rad]. In this assumption, the following equation (16) is obtained by integrating the above-described equation (15) with the second-order time.

By solving for passenger posture theta ₃ The equation (16), to obtain the following equation (17).

From equation (16) for the passenger posture theta _3, obtain the following equation (18) for occupant posture estimation value theta ₃ ^. Thereby, the passenger posture estimator 108 calculates the passenger posture estimation value θ ₃ ^ using the equation (18).

Here, each symbol in the above formula is defined as follows.
T _m : represents a torque command that is a target value of the motor torque, and both the motor torque and the torque command will be briefly described using the same symbol T _m .

Therefore, the occupant posture estimator 108 calculates the occupant posture estimated value θ ₃ ^ based on the input platform inclination angle θ ₁ , wheel angle θ ₂ , and motor torque command T _m (18). Can be calculated. The input T _m indicates the torque command value (T _m or T _mp ) calculated by the controller 102 before one control cycle.

Next, the operation principle of the backward fall condition determination unit 109 will be described.
In the relationship between the posture of the occupant 202 and the wheel angle, the condition that the occupant 202 is likely to fall backward can be expressed using the following equation (19).

In the equation (19), the passenger posture θ ₃ is negative and the acceleration at the wheel angle θ ₂ is positive (that is, the center of gravity of the passenger 202 is rearward and the inverted moving body 201 is It shows a state of accelerating forward). This is because in such a situation, since the acceleration of the wheel is forward, the occupant 202 is pulled relatively rearward, so that it is considered that the possibility of falling backward is high.

Therefore, the backward tipping condition determination unit 109 determines whether or not the backward tipping condition is satisfied based on the input passenger posture estimation value θ ₃ ^ and the acceleration of the wheel angle θ ₂ by the following equation (20). can do. The backward fall condition determination unit 109 outputs a signal indicating whether or not the backward fall condition is satisfied as a backward fall condition determination result.

Next, the operation principle of the passenger attitude time differential estimator 110 will be described.
First, the equation (14) in the above equation of motion is rewritten as shown in the following equation (21).

  An estimator for this equation (21) is realized by the following equation (22).

ここで、上式における各記号は、以下の通り定義される。なお、記号チルダ「〜」は、推定誤差であることを示す。
ｓ：搭乗者姿勢推定誤差θ_３ ^〜
ｃ：搭乗者姿勢推定誤差θ_３ ^〜が０に収束する速さ
Ｍ：推定器パラメータ
ｓｇｎ（・）：シグナム関数

Here, each symbol in the above formula is defined as follows. The symbol tilde “˜” indicates an estimation error.
s: Passenger posture estimation error θ ₃ ^~
c: Speed at which the passenger posture estimation error θ ₃ ^˜ converges to 0 M: Estimator parameter sgn (•): Signum function

  By subtracting this equation (22) from the above equation (21), an estimation error equation shown in the following equation (23) is obtained.

In this formula (23), when converging the parameter s representing the occupant posture estimation error theta ₃ dynamics ^~ 0, ^~ occupant posture estimation error theta ₃ to 0 at a rate of exp (-c · t) Converge. That is, the occupant posture estimation error θ ₃ ^˜ converges to the occupant posture θ ₃ at a speed of exp (−c · t).

In order to determine an estimator parameter M that converges the parameter s representing the dynamics of the passenger posture estimation error θ ₃ ^to 0 to 0, a Lyapunov function candidate V shown in the following equation (24) is introduced.

  The following equation (25) is obtained by differentiating this equation (24) by first-order time.

  It can be seen that the estimator parameter M takes a negative value for all s when the estimator parameter M satisfies the condition shown in the following expression (26) with respect to the value obtained by the expression (25).

Therefore, since Expression (25) takes a negative value according to Expression (26), the Lyapunov function candidate V of Expression (24) decreases monotonously while taking a positive value and converges to zero. When the Lyapunov function candidate V decreases to 0, the parameter s representing the dynamics of the occupant posture estimation error θ ₃ ^˜ converges to 0, and the following equation (27) is established.

Therefore, the occupant posture time differential estimator 110 is based on the platform inclination angle θ ₁ , the wheel angle θ _2, and the estimated occupant posture value θ ₃ ^ that are input. θ ₃ ^（(·) and θ ₃ ^（(··) ) can be calculated by Equation (22) and Equation (26). The occupant posture time differential estimator 110 detects the occupant posture time differential estimation value (θ ₃ ^ ^(·) , θ ₃ ^ ^(··) ) only when the backward fall condition (formula (20)) is satisfied. Is calculated and nothing is executed when the backward fall condition (formula (20)) is not satisfied.

Note that without using the passenger posture time derivative estimator 110, by directly time differential was an occupant posture estimation value theta _{3 ^} calculated by the equation (18) described above, the occupant posture estimation value theta _{3 ^} time It is also possible to calculate a differential value. However, when the time derivative value of the estimated passenger posture value θ ₃ ^ is calculated in this way, a value containing a lot of noise may be obtained. If the control for avoiding backward falls is performed using such a value containing a lot of noise, the effect of avoiding backward falls may be halved. Therefore, in this embodiment, by using the passenger posture time differential estimator 110, it is possible to estimate the time differential value of the passenger posture estimated value θ ₃ ^ containing almost no noise.

Next, the principle of operation of the backward tipping avoidance torque command calculator 112 will be described.
First, when a backward fall condition (equation (20)) is satisfied, passenger posture theta ₃ to be to monotonously increases toward the 0 [rad], it is possible to avoid a backward fall of the rider 202 it can. That is, the motor torque T _m of Equation (28) holds less, and controls the operation of the inverted vehicle 201.

Here, each symbol in the above formula is defined as follows.
t _p : Time when the rearward fall avoidance torque command computing unit 111 receives the rearward fall condition determination result that the rearward fall condition determination unit 109 satisfies the rearward fall condition (formula (20)) σ: positive number, boarding Speed at which the person's posture θ ₃ converges to 0 [rad] from the negative direction

  The following formula (29) is obtained by using the above formula (28) and formula (13).

Accordingly, the backward tipping avoidance torque command calculator 111 receives the platform inclination angle θ ₁ , the wheel angle θ ₂ , the passenger posture estimated value θ ₃ ^, and the passenger posture time derivative estimated value (θ ₃ ^ ⁽ Based on the following equation (30 ⁾ , θ ₃ ^ ^(••) ), the backward fall avoidance torque command T _mp can be calculated by the following equation (30). Thus, by performing the control based on a backward fall avoid torque command T _mp, can be converged passenger posture theta ₃ to 0 [rad], it is possible to avoid a fall of the occupant 202. The rear fall avoidance torque command calculator 111 calculates the rear fall avoidance torque command _Tmp only when the rear fall condition (formula (20)) is satisfied, and the rear fall condition (formula (20)) is satisfied. If not, do nothing.

In accordance with the operation principle described above, the occupant posture estimator 108 calculates the occupant posture estimated value θ ₃ ^ based on the equation (18). The backward tipping condition determination unit 109 determines whether the backward tipping condition is satisfied based on Expression (20). The passenger posture time differential estimator 110, when the rearward fall condition is satisfied, the passenger posture time differential estimated value (θ ₃ ^ ^(•) , θ ₃ ^ based on the equations (22) and (26). ^{(・ ・)} ) ^Is calculated. When the backward tipping condition is satisfied, the backward tipping avoidance torque command calculator 111 calculates the backward tipping avoidance torque command _Tmp based on the equation (30). The controller 103, when a backward fall condition is met, so that the motor torque T _m to follow the rear tipping avoid torque command T _mp, and controls the rotation of the motor 104.

Various parameters (passenger mass m ₁ , platform occupant center-to-center distance l _c , wheel mass m ₂ , wheel radius r, wheel inertia moment J ₂ related to the axle, etc.) used in the calculation of equation (18) and the like are respectively An appropriate value is set. Among these parameters, the passenger mass m ₁ and the platform occupant center-of-gravity distance l _c may be set in advance by the user, or the inverted moving body 201 may be a known method at the time of boarding or the like. It is good also as what estimates and sets automatically.

  In this way, according to the present embodiment, it is possible to estimate the posture of the occupant 202 while the inverted mobile body 201 is traveling without adding a special detector. Then, based on the estimated value of the posture of the occupant 202, it is determined whether or not the condition that the possibility of falling backward is high is satisfied. If it is determined that the possibility of falling backward is high, the passenger 202 The operation of the inverted moving body 201 can be controlled so as to easily avoid the falling (control that places more importance on preventing the passenger 202 from falling backward compared to maintaining the inverted moving body 201 in an inverted state). To implement).

Subsequently, a simulation result for the present embodiment will be described below. The numerical values used for the simulation are as follows.
m ₁ = 70 [kg],
J ₁₀ = 25.2 [kg · m ² ],
m ₂ = 5 [kg],
J ₂ = 0.025 [kg · m ² ],
l _c = 0.8 [m],
r = 0.1 [m],
g = 9.8 [m / s ² ],
σ = 0.2 (2π) [rad / s],
d = 0 [N · m],
θ ₁ (0) = π / 4 [rad],
θ ₁ ^(·) (0) = 0 [rad / s],
θ ₁ ^(··) (0) = 0 [rad / s ² ],
θ ₂ (0) = 0 [rad],
θ ₂ ^(·) (0) = 60 [rad / s],
θ ₂ ^(··) (0) = 0 [rad / s ² ],
θ ₃ (0) = − π / 4 [rad],
θ ₃ ^(•) (0) = 0 [rad / s],
θ ₃ ^(··) (0) = 0 [rad / s ² ]

Here, each symbol is defined as follows.
θ ₁ (0): Initial value of platform tilt angle θ ₁ θ ₁ ^(•) (0): Initial value of platform tilt angular velocity θ ₁ ^(•) θ ₁ ^(•) (0): Platform tilt angular acceleration θ ₁ ^(··) initial value θ ₂ (0): initial value of wheel angle θ ₂ θ ₂ ^(·) (0): initial value of wheel angular velocity θ ₂ ^(·) θ ₂ ^(··) (0): wheel Initial value of angular acceleration θ ₂ ^(•) θ ₃ (0): Initial value of passenger posture θ ₃ θ ₃ ^(•) (0): First-order time differential value θ ₃ ^{(•) of} passenger posture θ ₃ Initial value θ ₃ ^(••) (0): Initial value of second-order time derivative θ ₃ ^(••) of passenger posture θ ₃

  This simulation shows an example of numerical calculation when avoiding the passenger 202 from falling backward with respect to the above numerical example. This simulation simulates a situation in which the occupant 202 loses the balance backward while the inverted moving body 201 moves forward at a constant speed. In this situation, when the passenger 202 loses the balance backward, the upper body of the passenger 202 is leaning back, but the sole of the passenger 202 arrives without leaving the platform 101. Suppose it remains.

  3 to 5 are graphs showing the simulation results according to the present embodiment in the above-described situation. FIG. 3 is a graph showing a time change of a platform angle and a passenger posture angel. FIG. 4 is a graph showing a temporal change in wheel angular speed. FIG. 5 is a graph showing a time change of a torque reference (torque reference input).

In FIG. 3, the occupant posture θ ₃ and the occupant posture estimated value θ ₃ ^ according to the present embodiment are shown using solid lines, and the platform inclination angle θ ₁ is shown using broken lines. Incidentally, the occupant posture estimator 108 were passenger posture estimation value theta _{3 ^} calculated based on equation (18), in order to better match the passenger posture theta _3, shown overlapping the passenger posture theta ₃ ing.

In FIG. 3, the timing when the passenger 202 loses the balance backward as described above is 0 [s]. At this time, the platform inclination angle θ ₁ is π / 4 [rad], and the occupant posture θ ₃ is −π / 4 [rad] (that is, the platform 101 is tilted forward, but the The posture is tilted backward). Then, it is assumed that the backward fall condition is satisfied at 0 [s].

In the prior art, the platform 101 and the passenger 202 illustrated in FIG. 2 are regarded as one load body, and the inverted state of the load body is maintained. However, since the platform 101 and the occupant 202 are not actually integrated, according to the prior art, as a result of trying to maintain only the inverted state of the platform 101, the occupant 202 is pulled backwards and is safely boarded. (That is, the occupant posture θ ₃ monotonously decreases from −π / 4 [rad] with respect to the situation shown in FIG. 3).

On the other hand, in the present embodiment, in order to avoid the passenger 202 from falling backward, the passenger posture estimator 108 estimates the passenger posture estimated value θ ₃ ^ (shown by a solid line in FIG. 3). Based on the estimated passenger posture estimation value θ ₃ ^, it is determined whether or not the passenger 202 has lost the balance backward (whether or not the rearward fall condition (formula (20)) is satisfied). It was determined by instrumental 109, passenger 202 if you have unbalanced backward controls the occupant posture theta ₃ to converge to 0 [rad].

In the present embodiment, in FIG. 3, the platform inclination angle θ ₁ gradually decreases as the wheel angular velocity θ ₂ changes with time. When the passenger posture θ ₃ converges to 0 [rad], it is determined that the passenger 202 has not lost the balance backward, and normal inversion control based on only the platform inclination angle θ ₁ is performed.

As shown in FIG. 4, the wheel speed rapidly decreases between 0 [s] and 1.5 [s] in order to apply a forward acceleration to the passenger 202 who is out of balance at the rear. deceleration and, thereafter, it is the passenger posture θ ₃ and gradually accelerated so as to converge to 0 [rad]. That is, once the speed is reduced, a forward force is applied to the backward passenger 202, and after the posture of the passenger 202 returns to some extent, the posture of the passenger 202 may be returned by its inertia. After that, it is controlled to increase the speed by accelerating the wheel.

In Figure 5, since it is determined already occupant 202 is assumed to have unbalanced rearward, the rear tipping avoid torque command T _mp is calculated as the torque command T _m. In FIG. 5, the backward tipping avoidance torque command _Tmp initially takes a relatively large value in order to apply a forward acceleration to the passenger 202 whose balance is lost backward. Then, as the passenger posture θ ₃ approaches 0 [rad], the backward fall avoidance torque command _Tmp gradually decreases, and reaches a value corresponding to the inertial force of the load body that combines the platform 101 and the passenger 202. And converge.

  As described above, according to the present invention, the posture of the occupant 202 can be estimated during the traveling of the inverted moving body 201 without adding a special detector. Therefore, good control can be realized from the viewpoint of safety and riding comfort.

  From the viewpoint of safety, for example, when it is determined whether or not a condition that has a high possibility of falling backward is satisfied based on the estimated value of the posture of the passenger 202 and it is determined that the possibility of falling backward is high, The operation of the inverted mobile body 201 is controlled so that the person 202 can easily avoid the rearward fall (control that places greater importance on preventing the passenger 202 from falling backward than maintaining the inverted state of the inverted mobile body 201) can do.

  In addition, from the viewpoint of ride comfort, it is possible to control in consideration of the posture of the passenger 202. For example, by adjusting the moving speed of the inverted moving body 201 according to the posture of the passenger 202, motion sickness Etc. can be suppressed and the ride comfort of the passenger can be improved.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. For example, in Embodiment 1 described above, the case where the rotating body included in the inverted moving body 201 is a pair of opposed wheels 106 has been described as an example, but the present invention is not limited to this. That is, the rotating body may be configured by one or three or more wheels, or one or a plurality of spherical driving wheels may be used.

  Further, the shape of the platform 101 on which the passenger 202 is boarded is not limited, and any shape on which the passenger 202 can board can be adopted. The present invention can be applied regardless of whether or not the inverted mobile body 201 has a handle that can be gripped by the occupant 202, but the inverted mobile body 201 that does not have a handle is more suitable for the platform 101. And the passenger 202 cannot be reliably handled as a single unit, and thus the effect of the present invention can be exerted more strongly.

  Furthermore, in the above-described first embodiment, the operation control of the inverted mobile body 201 for determining whether or not the possibility of falling backward is high and avoiding backward falling has been described as an example. The invention is not limited to this. That is, based on the estimated value of the posture of the passenger 202, it is possible to determine whether or not there is a high possibility of falling forward, and to control the operation of the inverted moving body 201 for avoiding forward falling. is there.

101 platform,
102 platform tilt angle detector,
103 controller,
104 motor,
105 reducer,
106 wheels,
107 wheel angle detector,
108 Passenger attitude estimator,
109 backward fall condition determiner,
110 Passenger attitude time differential estimator,
111 Back fall avoidance torque command calculator,
201 inverted mobile,
202 passenger,

Claims (10)

A boarding area on which the passengers board;
A rotating body having a circular cross section for moving the boarding board;
The tilt angle with respect to the vertical direction of the boarding board, the rotation angle of the rotating body, the rotational drive torque command of the rotating body, the mass of the rotating body, the radius of the rotating body, and the rotation axis of the rotating body Based on the moment of inertia, the mass of the occupant, and the distance between the boarding platform and the center of gravity of the occupant, the occupant attitude with respect to the vertical direction of the occupant is estimated as an estimated occupant attitude value. A passenger attitude estimator;
A controller that controls the rotational drive of the rotating body based on the inclination angle of the boarding base with respect to the vertical direction, the estimated passenger posture estimated by the passenger attitude estimator, and the rotational angle of the rotating body. When,
Inverted mobile body with Back to determine whether or not the passenger is likely to fall backward based on the estimated passenger posture estimated by the passenger posture estimator and the rotation angle of the rotating body Further comprising a fall condition judging device,
The controller is
When it is determined that the condition that the passenger is likely to fall backward is satisfied by the backward fall condition determiner, control is performed so as to avoid the passenger from falling backward. The inverted moving body according to claim 1. The tilt angle with respect to the vertical direction of the boarding base, the rotation angle of the rotating body, the passenger posture estimated value estimated by the passenger posture estimator, the time differential value of the passenger posture, and the mass of the rotating body And avoiding a backward fall based on the radius of the rotating body, the moment of inertia related to the rotation axis of the rotating body, the mass of the occupant, and the distance between the boarding platform and the center of gravity of the occupant. A reverse overturn avoidance torque command calculator for calculating a torque command;
The controller is
When it is determined that the condition that the passenger is likely to fall backward is satisfied by the backward fall condition determiner, based on the backward fall avoidance torque command calculated by the backward fall avoidance torque command calculator The inverted moving body according to claim 2, wherein control is performed. An inclination angle with respect to a vertical direction of the boarding base, a rotation angle of the rotating body, a passenger posture estimated value estimated by the passenger posture estimator, a mass of the rotating body, a radius of the rotating body, Based on the moment of inertia related to the rotation axis of the rotating body, the mass of the occupant, and the distance between the boarding platform and the center of gravity of the occupant, the time differential value of the occupant attitude is calculated as the occupant attitude time. Further comprising a passenger attitude time differential estimator for estimating as a differential estimate,
The backward tipping avoidance torque command calculator is
The tilt angle of the boarding base with respect to the vertical direction, the rotation angle of the rotating body, the passenger posture estimated value estimated by the passenger posture estimator, and the passenger posture time estimated by the passenger posture time differential estimator Between the differential estimated value, the mass of the rotating body, the radius of the rotating body, the moment of inertia related to the rotation axis of the rotating body, the mass of the occupant, and the center of gravity of the boarding platform and the occupant The inverted moving body according to claim 3, wherein a backward tipping avoidance torque command is calculated based on the distance. The passenger posture estimator is
θ ₁ : angle of inclination of the boarding base with respect to the vertical direction,
θ ₂ : rotation angle of the rotating body,
r: radius of the rotating body,
l _c : distance between the boarding platform and the center of gravity of the passenger,
m ₁ : mass of the passenger,
m ₂ : mass of the rotating body,
J ₂ : moment of inertia related to the rotation axis of the rotating body,
T _m : rotational drive torque command for the rotating body,
θ ₃ ^: As the passenger posture estimation value,
Using the following equation (31), the estimated occupant posture is estimated.

The inverted moving body according to any one of claims 1 to 4, wherein the inverted moving body is characterized in that The backward fall condition determiner is
θ ₂ : rotation angle of the rotating body,
θ ₃ ^: As the passenger posture estimation value,
Using the following equation (32), it is determined whether or not the condition that the passenger is likely to fall backward is satisfied.

The inverted movable body according to any one of claims 2 to 5, wherein The backward tipping avoidance torque command calculator is
θ ₁ : angle of inclination of the boarding base with respect to the vertical direction,
θ ₂ : rotation angle of the rotating body,
θ ₃ ^: the estimated passenger posture value,
θ ₃ ^ ^(•) , θ ₃ ^ ^(••) : Time derivative estimated value of the passenger posture,
r: radius of the rotating body,
l _c : distance between the boarding platform and the center of gravity of the passenger,
m ₁ : mass of the passenger,
m ₂ : mass of the rotating body,
J ₂ : moment of inertia related to the rotation axis of the rotating body,
T _mp : As for the backward fall avoidance torque command,
The backward fall avoidance torque command is calculated using the following equation (34).

The inverted moving body according to any one of claims 3 to 6, characterized in that The passenger attitude time differential estimator is
θ ₁ : angle of inclination of the boarding base with respect to the vertical direction,
θ ₂ : rotation angle of the rotating body,
θ ₃ ^: the estimated passenger posture value,
r: radius of the rotating body,
l _c : distance between the boarding platform and the center of gravity of the passenger,
m ₁ : mass of the passenger,
m ₂ : mass of the rotating body,
J ₂ : moment of inertia related to the rotation axis of the rotating body,
T _mp : the backward fall avoidance torque command,
θ ₃ ^ ^(•) , θ ₃ ^ ^(••) : the passenger posture time derivative estimated value,
The passenger posture time differential estimated value is estimated using the following equation (33).

The inverted moving body according to any one of claims 4 to 7, characterized in that The inverted moving body according to any one of claims 1 to 9, wherein the rotating body is two wheels facing each other. A control method for an inverted moving body comprising: a boarding board on which a passenger boards; and a rotating body having a circular cross section for moving the boarding board,
The tilt angle with respect to the vertical direction of the boarding board, the rotation angle of the rotating body, the rotational drive torque command of the rotating body, the mass of the rotating body, the radius of the rotating body, and the rotation axis of the rotating body Based on the moment of inertia, the mass of the occupant, and the distance between the boarding platform and the center of gravity of the occupant, the occupant attitude with respect to the vertical direction of the occupant is estimated as an estimated occupant attitude value. A passenger posture estimation step;
A control step for controlling the rotational drive of the rotating body based on the inclination angle of the boarding base with respect to the vertical direction, the estimated passenger posture estimated by the passenger attitude estimator, and the rotational angle of the rotating body. When,
A method for controlling an inverted mobile object having

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