KR102043403B1 - Motorized moving object and method for controlling the same - Google Patents

Abstract

Based on the kinetic information associated with the moving body, such as an electric moving bogie, calculating the drive torque for the driving wheel of the moving body to calculate the control current for controlling the motor associated with that driving wheel, and thereby controlling the driving wheel, Provided is a control method of a mobile body, which compensates for a movement error of the mobile body by at least one of centrifugal force and inertia generated according to the movement of the mobile body through control of a driving wheel.

Description

MOTORIZED MOVING OBJECT AND METHOD FOR CONTROLLING THE SAME}

Embodiments relate to a method of controlling a moving object such as an electric moving cart, and more particularly, to a method of compensating for a moving error of a moving object due to centrifugal force / inertia generated by moving a moving object by controlling a touch moving object based on acceleration information. do.

Background Art Recently, a mobile vehicle such as a moving vehicle or a cart has been widely used for carrying and transporting an object in various applications such as daily environments and industrial sites. In the case of loading a heavy object on the moving object, it is difficult to correctly control the movement (ie, speed and direction) of the moving object in carrying the object through the moving object.

Accordingly, a motor-driven mobile body has been developed that includes a motor in a wheel to form a driving wheel and to move the mobile body by the operation of the driving wheel. In the case of using such an electric movable body, even if a user applies only a small force to the movable body, the movable body can be easily moved through the driving wheel driven by the motor.

However, for the stable use of such a motorized moving object, it is necessary to appropriately control the posture and the moving speed of the electric moving object in accordance with the state of the ground and its moving speed and direction.

In order to control the posture and the moving speed of the motorized moving object, data measured by high level sensors such as an inertial measurement unit and an encoder may be used. However, such components such as IMUs and encoders are expensive, and there is a problem that it is difficult to stably control the moving object at low speed even when controlling the posture and the moving speed of the motorized moving object using the same.

Therefore, there is a need for a method of controlling a motorized moving object that can stably control the posture and the moving speed of the electric moving object even at a low speed without requiring expensive and complicated sensors such as an IMU and an encoder.

Published Utility Model Publication No. 20-2012-0001845 (published March 12, 2012) includes a pair of left and right manipulation handles, and after detecting a force applied to the left and right manipulation handles, An electric cart capable of driving by driving a drive motor is disclosed.

The information described above is merely for the sake of understanding, and may include content that does not form part of the prior art, and may not include what the prior art may suggest to those skilled in the art.

In one embodiment, the driving torque for the driving wheel is calculated based on the dynamic information including the modeling information of the moving body and the speed information associated with the driving wheel of the moving body obtained through a low-level sensor. And it can provide a method for controlling the driving wheel based on this.

According to an embodiment of the present disclosure, a driving torque for a driving wheel and a control current for a motor are calculated using the acceleration information obtained based on the modeling information of the moving body and the speed information obtained through the level sensor, and the driving wheel is controlled. Can be provided.

In one embodiment, when an external force is applied to the moving body, the force information obtained by the force sensor is converted into acceleration information, and the drive torque for the driving wheel and the control current for the motor are calculated by using the converted acceleration information. It is possible to provide a method of controlling the drive wheels.

In one aspect, there is a method for controlling the movement of a moving body, the method comprising: controlling a motor associated with a driving wheel of the moving body by calculating a driving torque for the driving wheel of the moving body based on dynamic information associated with the moving body. Calculating a control current and controlling the driving wheel by controlling the motor based on the calculated control current, wherein the dynamics information includes a modeling information and a low-level of the predefined moving object. And the speed information associated with the driving wheel obtained through the sensor, wherein the driving torque is calculated using the acceleration information obtained based on the modeling information and the speed information, and the driving wheel is driven by the control current. By controlling, at least one of the centrifugal force and the inertia generated by the movement of the movable body Provided is a control method of a mobile body, by which a movement error of the mobile body is compensated for.

The low level sensor may be a hall sensor.

The acceleration information may be based on a value estimated by applying a Proportional-Derivative (PD) or Proportional Integral Derivative (PID) controller to position information associated with the moving object estimated based on the integration of the speed information and the speed information. .

The acceleration information may be information indicating an acceleration error occurring when the moving body moves, depending on the position of the motor and the position of the driving wheel in the moving body.

The drive wheels may include left drive wheels and right drive wheels.

The driving torque may be calculated by Equation 1 as driving torques for the left driving wheel and the right driving wheel.

[Equation 1]

T _CL is a drive torque for the left drive wheel, T _CR is a drive torque for the right drive wheel, A and B are constants obtained based on the modeling information, respectively, and d is the left side. Distance from the center of the driving wheel and the right driving wheel to the left driving wheel or the right driving wheel, A _x is the acceleration error with respect to the moving displacement x of the moving body, and A _θ is the rotation angle of the moving body It may be the acceleration error with respect to θ .

The control current can be calculated by dividing the torque constant associated with the drive wheel or the motor by the drive torque.

The modeling information may include weight of the movable body, weight of the driving wheel, radius of the driving wheel, positional relationship information of the driving wheel with respect to the center of gravity of the movable body, and an inertia moment associated with the movable body.

The acceleration information may change according to the movement of the moving body.

Using the control current calculated based on the drive torque calculated according to the changing acceleration information, the drive wheels can be continuously controlled.

The generating of the control current may include converting the force information obtained by the force sensing sensor into acceleration information when the external force is applied to the moving object, and calculating the driving torque by further using the converted acceleration information. Control current can be generated.

The drive wheels may include left drive wheels and right drive wheels. The driving torque may be calculated by Equation 2 as driving torques for the left driving wheel and the right driving wheel.

[Equation 2]

The T _CL is a drive torque for the left drive wheels, the T _CR is a drive torque for the right drive wheels, A and B are constants obtained based on the modeling information, respectively, and the F _L external force. Among the forces transmitted to the left driving wheel, F _R is the force transmitted to the right driving wheel of the external force, A _A and A _b may be a constant for converting the external force into acceleration.

In another aspect, an electrically driven mobile body, comprising: a drive wheel driven by a motor, at least one low-level sensor for obtaining speed information associated with the drive wheel, and dynamics associated with the mobile body Based on the information, calculating the drive torque for the drive wheel, calculating a control current for controlling the motor associated with the drive wheel, and controlling the drive wheel by controlling the motor based on the calculated control current. And a control unit, wherein the dynamic information includes predefined modeling information and the speed information of the moving object, and the control unit uses the acceleration information obtained based on the modeling information and the speed information to adjust the driving torque. Calculate, and the drive wheel is controlled by the control current, thereby the movement The movement of the centrifugal force and inertia caused by the moving object, at least one being a movement compensation error of the mobile body according to is provided.

The low level sensor may be a hall sensor.

The control unit may estimate the acceleration information based on a value of applying a Proportional-Derivative (PD) or Proportional Integral Derivative (PID) controller to position information associated with the moving object estimated based on the integration of the speed information and the speed information. Can be.

The drive wheels may include a pair of left drive wheels and right drive wheels.

The controller may calculate the driving torque as driving torque for the left driving wheel and the right driving wheel, respectively.

The movable body may further include a handle part for applying an external force by the user to the movable body and a force sensing sensor for measuring the external force applied through the handle part.

When the external force is applied to the moving body, the controller may convert the force information obtained by the force sensing sensor into acceleration information and further calculate the driving torque using the converted acceleration information.

The movable body may further include a manual wheel configured to rotate according to the movement of the movable body without driving by the power and to adjust the direction according to the moving direction of the movable body.

The movable body may further include a loading unit for loading an object to be transported.

The control unit may continuously control the driving wheel by using the control current calculated by calculating the driving torque according to the acceleration information that changes according to the movement of the moving body.

Based on the dynamic information including the modeling information of the moving object and the speed information associated with the driving wheel of the moving object obtained through the low-level sensor, the driving torque for the driving wheel is calculated and driven based on the dynamic information. By controlling the wheels, it is possible to stably control the posture and the moving speed of the moving body without having expensive parts such as an IMU and an encoder.

It is possible to stably control the attitude and the moving speed of the moving body even at low speed by calculating the driving torque for the driving wheel and the control current for the motor by using the acceleration information rather than the speed information associated with the moving body.

When an external force is applied to the moving object by the user, the driving wheel is controlled by converting the force information related to the external force into acceleration information and using the converted acceleration information to calculate the drive torque for the drive wheel and the control current for the motor. Thus, the moving object can be controlled by appropriately compensating for an error caused by the difference between the walking speed of the user and the moving speed of the moving object.

1 illustrates a motor driven (electric) moving body, according to one embodiment.
2 is a structural diagram showing configurations of the motorized moving body according to one embodiment.
3 shows the positional relationship between the configurations of the motorized mobile body and the operation of the components in the movement of the mobile body according to one embodiment.
4 illustrates a side view and a top view of the motorized moving body when an external force is applied by a user according to an example.
5 illustrates a control method of a motor associated with driving wheels of an electric movable body, according to an embodiment.
6 to 8 illustrate a comparison result between control of a mobile body using acceleration information and control of a mobile body using speed information according to an example.
9 is a flowchart illustrating a method of controlling a moving object based on dynamic information associated with the moving object, according to an embodiment.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 illustrates a motor driven (electric) moving body, according to one embodiment. On the other hand, Figure 2 is a structural diagram showing the specific configuration of the motorized moving body shown in FIG.

In the following description, for convenience of description, the "moving body 100" is shown in the form of a moving cart including a handle 130, but the embodiments are in any form including a driving wheel driven by a motor. It can be applied to a truck, cart, or robot.

The movable body 100 may be, for example, an electric trolley which can load and move an object to be carried.

The movable body 100 includes a loading unit 115 for loading an object to be transported, a driving wheel 111a and 111b, which are disposed on the left and right sides as shown, for driving a pair of driving wheels 111a and 111b. It may include the motor (112a, 112b).

The stacking unit 115 may be a main body of the mobile unit 100, and a configuration including the controller 140 to be described later may be included in the stacking unit 115.

The motors 112a and 112b may be provided with respect to the left driving wheel 111a and the right driving wheel 111b as shown. Alternatively, only one motor 112a or 112b may be provided for the driving wheels 111a and 111b.

The moving object 100 may include at least one low-level sensor 161a or 161b for obtaining speed information associated with the driving wheels 111a and 111b. The low level sensors 161a and 161b may refer to sensors having a simple structure, unlike an IMU or an encoder having a complicated structure. For example, the low level sensors 161a and 161b may be hall sensors. The hall sensors 161a and 161b may be included in, for example, the motors 112a and 112b which are brushless motors, and may acquire information regarding the rotation angle of the associated motor even without a separate encoder. The obtained information about the rotation angle may correspond to speed information associated with the driving wheels 111a and 111b. Alternatively, speed information associated with the driving wheels 111a and 111b may be calculated based on the obtained information about the rotation angle.

The moving object 100 may include a controller 140 that acquires and processes data from the sensors 161a and 161b and controls driving of the motors 112a and 112b. The controller 140 may execute a program or application used to manage and control the configuration of the moving object 100, and may process necessary operations. The controller 140 may be a processor or at least one core in the processor.

The controller 140 may calculate driving torques for the driving wheels 111a and 111b based on the dynamic information associated with the moving object 100 and control the motors 112a and 112b associated with the driving wheels 111a and 111b. The control current can be calculated. In addition, the controller 140 may control the driving wheels 111a and 111b by controlling the motors 112a and 112b based on the calculated control current. In other words, the controller 140 may include a motor controller for controlling each of the motors 112a and 112b.

The dynamic information associated with the moving object 100 may include modeling information of the moving object 100 and velocity information obtained from the sensors 161a and 161b. The controller 140 may obtain the obtained acceleration information based on the modeling information and the speed information included in the dynamic information, and calculate the driving torque for the driving wheels 111a and 111b using the obtained acceleration information. . In other words, the controller 140 may calculate driving torques for the left driving wheel 111b and the right driving wheel 111b, respectively.

The controller 140 may calculate the control currents for the motors 112a and 112b based on the calculated driving torque, and control the motors 112a and 112b using the calculated control currents (ie, the moving agents 100). The driving wheels 111a and 111b of the movable body 100 can be controlled.

As the driving wheels 111a and 111b are controlled by the control current calculated by the controller 140, the movement error of the movable body 100 due to at least one of the centrifugal force and the inertia generated by the movement of the movable body 100 is compensated for. Can be. Therefore, the movable body 100 can be stably moved.

A more detailed method of calculating the drive torque for the drive wheels 111a and 111b and the control current for the motors 112a and 112b will be described in more detail with reference to FIG. 5 to be described later.

The movable body 100 may further include manual wheels 151a and 151b configured to rotate according to the movement of the movable body 100 without being driven by a motor or other power, and to adjust a direction according to the moving direction of the movable body 100. Can be. The manual wheels 151a and 151b may be wheels that rotate manually according to the rotation of the driving wheels 111a and 111b or an external force by the user. The manual wheels 151a and 151b may be configured to be adjustable in direction according to the moving direction of the movable body 100. In other words, the movable body 100 may be steered in a desired direction according to the direction adjustment of the manual wheels 151a and 151b.

The movable body 100 may further include a handle 130 for applying an external force by the user to the movable body 100. For example, an external force may be applied to the movable body 100 by the user holding the handle 130 and pushing the movable body 100.

The moving body 100 may further include force detection sensors 121 and 122 for measuring an external force applied through the handle 130. One force sensor 121 and 122 may be provided on each of the left and right sides. For example, the left force detection sensor 121 is configured to acquire force information transmitted to the left driving wheel 111a, and the right force detection sensor 122 is configured to acquire force information transmitted to the left driving wheel 111b. Can be. Alternatively, only one force sensor 121 or 122 may be provided at a position corresponding to the center of the handle 130.

The force sensors 121 and 122 may include, for example, strain gauges, and various devices capable of appropriately measuring the applied force such as a load cell may be used.

The controller 140 may calculate driving torques for the driving wheels 111a and 111b and control currents for the motors 112a and 112b by further considering force information obtained by the force sensors 121 and 122. For example, when an external force is applied to the moving object 100, the controller 140 may convert force information obtained by the force sensing sensors 121 and 122 into acceleration information, and drive using the converted acceleration information further. The drive torque for the wheels 111a and 111b can be calculated.

By the movable body 100 of the embodiment, even if the user is applied to the handle 130 and the force transmitted to the body portion of the movable body 100 is maintained, the magnitude of the force transmitted to the body portion is amplified so that the motor 112a, 112b Since the operation can be controlled, the user can easily move the object by manipulating the moving object 100 even when a heavy weight is loaded on the loading unit 115.

In addition, the driving wheels 111a and 111b are controlled based on the driving torque calculated in consideration of the external force by the user, so that when the user pushes the moving object 100, the walking speed of the user and the movement of the moving object 100 are performed. The error generated by the difference between the speeds can be properly compensated so that the moving object 100 can be controlled.

The moving object 100 is not limited to the electric moving cart shown, and may correspond to any kind of apparatus and robot capable of accepting an interaction from a user or amplifying a force applied from the user.

More detailed operations of the movable body 100 and the controller 140 will be described in more detail with reference to FIGS. 3 to 5 to be described later.

3 is a view illustrating a positional relationship between components of a motorized mobile body and operations of the components in the movement of the mobile body according to an embodiment, and FIG. 4 is a motorized type when an external force is applied by a user according to an example. The side view and the top view of the moving body are shown.

3 and 4, more specific examples of the movable body 100 described above with reference to FIGS. 1 and 2 are described.

In FIG. 3, the positional relationship between the components of the moving body 100 is shown. In the example shown, Cartesian coordinates are used that represent the global axes of x , y and θ . In the example shown, N ₁ , N ₂ may correspond to the x and y axes, respectively. θ may mean an angle formed by the moving direction of N ₁ and the moving object 100. θ is It may be a rotation angle of the moving body.

In the example shown in FIG. 3, d may be a distance from the center I of the left driving wheel 111a and the right driving wheel 111b to the left driving wheel 111a or the right driving wheel 111b. In other words, d may be defined as the center distance of the driving wheels 111a and 111b. r may represent the radius of the drive wheels 111a and 111b. L may represent a distance from the center of gravity of the movable body 100 to the center I of the driving wheels 111a and 111b. For example, the motors 112a and 112b may be provided at the center I.

The positions of d , L and r and the center I and the center of gravity of the moving object 100 may be part of modeling information associated with the moving object 100, and may be values previously known by the controller 140 as a predefined value. .

The acceleration information used to calculate the drive torque for the drive wheels 111a and 111b depends on the position of the motors 112a and 112b and the position of the drive wheels 111a and 111b in the movable body 100. It may be information indicating an acceleration error occurring when the 100 is moved.

FIG. 3 schematically illustrates the movable body 100, and unlike the illustrated example, only the manual wheels 151a and 151b of the driving wheels 111a and 111b and the manual wheels 151a and 151b are driven as the direction can be adjusted. The wheels 111a and 111b and the manual wheels 151a and 151b may be arranged differently from those shown in the directions.

As shown in FIG. 4, the user may apply external force to the movable body 100 by pushing the handle 130. The handle 130 may be provided at the driving wheels 111a and 111b as described above with reference to FIG. 1, but may be provided at the side of the manual wheels 151a and 151b as shown in FIG. 4. The driving wheels 111a and 111b and the wheels 151a and 151b may be provided at both sides. In addition, according to the direction in which the user wants to move the movable body 100, the user may apply external force to the movable body 100 by pulling the handle 130 as well as pushing the handle 130. According to the direction of the external force applied, the controller 140 determines the direction of rotation of the driving wheels 111a and 111b (that is, the direction of rotation of the motors 112a and 112b) (in a direction to amplify the external force from the user). Can be.

As described above, the description of the technical features described above with reference to FIGS. 1 and 2 may be applied as it is to FIGS. 3 and 4, and thus redundant descriptions thereof will be omitted.

5 illustrates a control method of a motor associated with driving wheels of an electric movable body, according to an embodiment.

The controller 140 described above with reference to FIG. 1 may include a main controller 520 and motor controllers 530a and 530b. The motor controller 530a may control driving of the motor 112a associated with the left driving wheel 111a, and the motor controller 530b may control driving of the motor 112b associated with the left driving wheel 111b.

The hall sensors 161a and 161b may be included in the motors 112a and 112b and the motors 112a and 112b may be, for example, brushless DC motors (BLDC motors). The signal obtained from the hall sensors 161a and 161b is directly transmitted to the main controller 520 or to the motor controllers 530a and 530b (or to the main controller 520 through the motor controllers 530a and 530b). Can be.

For example, VESC may be used as the motor controllers 530a and 530b, and Arduino 2560 may be used as the main controller 520. The motor controllers 530a and 530b may communicate with the main controller at a predetermined time interval (eg, 10 ms) through serial communication.

The main controller 520 is configured to drive torques for the driving wheels 111a and 111b and motors 112a and 112b based on the modeling information associated with the moving object 100 and the speed information obtained from the hall sensors 161a and 161b. The control current can be calculated. The motor controllers 530a and 530b may control the motors 112a and 112b using the calculated control current.

The main controller 520 may calculate the driving torque for the driving wheels 111a and 111b and the control current for the motors 112a and 112b by further considering the force information obtained from the force detection sensors 121 and 122. The force signals from the force detection sensors 121 and 122 may be amplified through the amplifiers 510a and 510b and then transferred to the main controller 520. For example, YZC-1B and HX711 may be used as the force sensing sensors 121 and 122 and the amplifiers 510a and 510b, respectively.

Hereinafter, the main controller 520 will be described in more detail how to calculate the drive torque for the drive wheels 111a and 111b and the control current for the motors 112a and 112b. The calculation and estimation described below with reference to equations may be performed by the controller 140 (or the main controller 520).

Equations 1 and 2 below may be torque relations represented by dynamic models of the left driving wheel 111a and the right driving wheel 111b, respectively. The torques represented by the kinetic models of the drive wheels 111a and 111b include coulomb friction torque, centrifugal torque and inertia torque for the center of moment and the center of the wheel. .

[Equation 1]

[Equation 2]

는 예컨대, 홀 센서일 수 있는 로우 레벨 센서(161a, 161b)에 의해 획득된 값으로부터 계산될 수 있다. 변수 위의 ·는 해당 변수의 미분 값을 의미할 수 있다. 나머지 변수들에 대해서는 앞서 도 3을 참조하여 설명되었다. T _L and T _R may be the drive torque (input torque) for the left drive wheel 111a and the right drive wheel 111b, respectively, and C _ml And C _mr may be Coulomb friction of the left driving wheel 111a and the right driving wheel 111b, M _c may be the weight of the movable body 100, and M _w is the weight of the driving wheels 111a and 111b. May be, and I ₃ of the moving object 100 It may be the moment of inertia in the z-axis direction, J may be the moment of inertia of the drive wheels (111a, 111b) relative to the axis of rotation, k is the moment of inertia of the drive wheels (111a, 111b), not the rotation axis It may be a moment of inertia about the axis. x may be a displacement of the moving object 100.

May be calculated from a value obtained by the low level sensors 161a, 161b, which may be, for example, hall sensors. · On a variable can mean the derivative of the variable. The remaining variables have been described above with reference to FIG. 3.

는 (v _L +v _R )/2로서 계산될 수 있다. 한편, θ의 미분 값인

는 1/d와 (-v _L +v _R )/2의 곱으로서 계산될 수 있다.

와

를 적분함으로써 θ와 이동 변위 x가 획득될 수 있다.The method of obtaining the above-described θ and the movement displacement x is described in more detail below with reference to FIG. 3. [theta] and the movement displacement x can be calculated from the values obtained by the low level sensors 161a, 161b present in association with the drive wheels 111a, 111b, respectively. Each of the low level sensors 161a and 161b may be a hall sensor. The speed v _L can be obtained from the left hall sensor 161a associated with the left drive wheel 111a and the speed v _R can be obtained from the left hall sensor 161b associated with the right drive wheel 111b. At this time,

Can be calculated as ( v _L + v _R ) / 2 . On the other hand, the derivative of θ

Is 1 / d and ( -v _L + v _R ) / 2 Can be calculated as a product.

Wow

By integrating θ and the displacement x Can be obtained.

The above-described modeling information associated with the movable body 100 includes the weight of the movable body 100, the weight of the driving wheels 111a and 111b, the radius of the driving wheels 111a and 111b, and the driving wheel 111a for the center of gravity of the movable body. , Position relation information (eg, d ) of 111b), and moments of inertia associated with the moving body (eg, I ₃ , J, and k) . The modeling information may be configured as values that are previously measured and defined as a predefined value at the manufacturing stage of the moving object 100.

Equations 1 and 2 may be rewritten by Equations 3 and 4 below. Viscosity torque and gravity torque as compared to inertial torque can be ignored.

[Equation 3]

[Equation 4]

Each of A and B may be a constant obtained based on modeling information. x and θ are It may be a value obtained from the low level sensors 161a and 161b (eg, a hall sensor) or a value that can be estimated / calculated from the obtained value. G (x) may represent a term related to gravity. In the case where the moving object 100 is operated on a flat surface, G (x) may be zero.

The torque in the actual system can be defined as in Equation 5 below.

[Equation 5]

τ _m can represent the torque in the actual system. M (θ) may represent a term related to the inertia force. G (θ) may represent the term related to gravity. θ _m may represent a state variable in the actual driving system of the moving object 100.

The torque in the modeled system can be defined as in Equation 6 below.

[Equation 6]

τ _v may represent the torque in the modeled system. M _v (θ) may represent a term related to the inertia force in the modeled system. G _v (θ) may represent a term related to the inertia force in the modeled system. θ _v may be defined as in Equation 7 below. θ _v may represent state variables in the modeled system. A proportional-derivative (PD) controller (or a proportional integral derivative) controller (PID) may be applied to Equation 7 to estimate the acceleration of the modeled system.

For example, the movable body 100 of the embodiment does not include components such as an IMU and an encoder, and includes only low level sensors 161a and 161b such as hall sensors, so that the exact position of the movable body 100 may not be known. The position of the moving object 100 may be estimated from the speed information obtained from the hall sensor, and the acceleration may be estimated therefrom. The controller 140 is associated with the moving object 100 estimated based on the integration of the acceleration information used to calculate the driving torque for the driving wheels 111a and 111b based on the speed information and the speed information obtained through the Hall sensor. The position information may be estimated based on a value obtained by applying a Proportional-Derivative (PD) or Proportional Integral Derivative (PID) controller. For example, the rotation angle of the motor associated with the driving wheels 111a and 111b to which the hall sensors are attached may be measured through the hall sensor, and the speed information and the position information may be estimated based on the hall sensor.

[Equation 7]

θ _m can be the rotation angle of the drive wheels 111a and 111b in the actual drive system, θ _des can be the rotation angle of the target drive wheels 111a and 111b and k _d is the D of the PD controller. It may be a gain value, and k _p may be a P gain value of the PD controller.

Assuming that the torque in the actual system in Equation 5 and the torque in the modeled system in Equation 6 are the same, Equation 8 below can be obtained.

[Equation 8]

는 0이 될 수 있고, 이를 정리하면 수학식 9가 획득될 수 있다.For Equation 8, Equations 9 and 10 can be obtained by applying the acceleration of the modeled system estimated above. In other words, assuming that values of Equations 6 and 8 are the same, the difference between the two equations may be zero. At this time,

May be 0, and in summary, Equation 9 may be obtained.

[Equation 9]

By arranging Equation 9, Equation 10 can be obtained.

[Equation 10]

If the inertia of the actual system and the modeled system are the same in Equation 10, Equation 11 can be obtained.

[Equation 11]

는 가속도 오차에 대응할 수 있다. e는 θ_des -θ_m 를 의미할 수 있다. 수학식 11에서 획득된 가속도 오차는 전술된 구동 바퀴(111a, 111b)에 대한 구동 토크를 계산하기 위해 사용되는 가속도 정보에 대응할 수 있다.

May correspond to an acceleration error. e may mean θ _des − θ _m . The acceleration error obtained in Equation 11 may correspond to the acceleration information used to calculate the driving torque for the driving wheels 111a and 111b described above.

Assuming that the inertia of the system and the inertia of the modeled system are the same, Equation 11 can be obtained.

If the acceleration error of Equation 11 is applied to Equation 3 described above and converted to the Cartesian coordinate system, the following Equation 12 may be obtained.

[Equation 12]

By arranging Equation 12 below, Equation 13 can be obtained.

[Equation 13]

일 수 있다. A_θ 는

일 수 있다. 이와 같이, 좌측 구동 바퀴(111a) 및 우측 구동 바퀴(111b)에 대한 구동 토크는 추정된 가속도 정보에 기반하여 계산될 수 있다. 구동 바퀴(111a, 111b)와 연관된 모터(112a, 112b)를 제어하기 위한 제어 전류는 수학식 13에 의해 구동 토크에 구동 바퀴(111a, 111b) 또는 모터(112a, 112b)와 연관된 토크 상수를 나눔으로써 계산될 수 있다(아래 수학식 14 참조). A _x may be an acceleration error with respect to the movement displacement x of the moving object 100, and A _θ may be an acceleration error with respect to the rotation angle θ of the moving object. A _x is

Can be. A _θ is

Can be. As such, the driving torques for the left driving wheel 111a and the right driving wheel 111b may be calculated based on the estimated acceleration information. The control current for controlling the motors 112a and 112b associated with the drive wheels 111a and 111b divides the torque constant associated with the drive wheels 111a and 111b or the motors 112a and 112b by the equation (13). It can be calculated as (see Equation 14 below).

[Equation 14]

K _τl may be a left driving wheel (111a) (or the motor (112a)) may be associated with a torque constant, K _τr is right drive wheels (111b) (or motor (112b)) are associated with constant torque. I _cl may be a control current value for controlling the motor 112a. I _cr may be a control current value for controlling the motor 112b.

The acceleration information calculated by estimating may change according to the movement of the moving object 100. The controller 140 may continuously control the driving wheels 111a and 111b by using the control current calculated by calculating the driving torque according to the acceleration information that changes according to the movement of the movable body 100.

In the following, the drive torque for the driving wheels 111a and 111b is calculated when an external force by the user is applied to the movable body 100 (eg, via the handle 130), and the motors 112a and 112b are calculated. A method of generating a control current for the following is described in more detail.

As described above, in the case where the moving object 100 is a device that is controlled by amplifying the applied force from the user, when the speed at which the user walks and the moving speed of the moving object 100 are different, a reaction force is generated by this speed difference. ) May occur. As a result, the movable body 100 cannot maintain a stable speed.

In order to solve this problem, it is possible to determine the driving torque for the driving wheels (111a, 111b) by applying the relationship of the equation (12) described above, and to calculate the control current for controlling the motor (112a, 112b).

When the external force is applied to the moving body 110, the controller 140 converts the force information acquired by the force sensors 121 and 122 into acceleration information, and further uses the converted acceleration information to drive wheels 111a and 111b. Drive torque can be calculated.

For example, the drive torque for the drive wheels 111a and 111b may be calculated by Equation 15 below.

[Equation 15]

As described above, T _CL is the drive torque for the left drive wheels 111a, T _CR is the drive torque for the right drive wheels 111b, and A and B are constants obtained based on the modeling information, respectively. Can be.

It may be a force transmitted to the left driving wheel 111a of the F _L external force. For example, F _L may correspond to the value obtained by the force sensor 121. F _R may be a force transmitted to the right driving wheel 111b of the external force. For example, F _R may correspond to the value obtained by the force sensing sensor 122. A _a and A _b may be constant values for converting external force into acceleration. A _a and A _b are values obtained through experiments. For example, A _a and A _b may be obtained through experiments of a trial-error method.

In other words, when an external force is applied to the moving object 100, the driving torque (and control current) for the driving wheels 111a and 111b is controlled based on the acceleration information, thereby driving torque (and control current) in the same dimension as the acceleration information. Can be controlled. Accordingly, the moving body 100 is more stable than the driving torque (and control current) in terms of speed, and in particular, the moving body 100 can be controlled more stably even at a low speed, and the acceleration and deceleration of the moving body 100 is repeated. You can solve the problem.

As described above, the description of the technical features described above with reference to FIGS. 1 to 4 may be applied to FIG. 5 as it is, and thus redundant descriptions thereof will be omitted.

6 to 8 illustrate a comparison result between control of a mobile body using acceleration information and control of a mobile body using speed information according to an example.

The moving object 100 is a non-interaction mode in which the control of the moving object 100 is performed in relation to Equation 12 described above (ie, no external force by the user), and the control of the moving object 100 in relation to Equation 15. It can be divided into the interaction mode (the external force of the user) is performed. According to the embodiment, the control of the mobile 100 that is robust against external fluctuations (ground and other external forces) in the non-interaction mode can be achieved. In addition, according to the embodiment, the moving object 100 may be controlled so that the user does not feel heterogeneity with respect to the external force (pushing or pulling force) of the user in the interaction mode.

In the embodiment, only the hall sensor is provided without the encoder attached to the motors 112a and 112b which are brushless motors, but the control at low speed can be performed stably.

6A illustrates an example of controlling the driving wheels 111a and 111b of the moving object 100 based on the speed information. It can be seen that the speeds of the left driving wheels and the right driving wheels 111a and 111b are unstable and fluctuating.

FIG. 6B illustrates an example of controlling the driving wheels 111a and 111b of the moving object 100 based on the acceleration information according to the embodiment. It can be seen that the speeds of the left driving wheels and the right driving wheels 111a and 111b are very stable compared to the example of FIG. 6 (a). Accordingly, it can be seen that the motors 112a and 112b do not include encoders, the motors 112a and 112b include only hall sensors, and even in an environment in which reaction force exists, stable control is achieved in the embodiment.

7 and 8 show the same dynamic information as that of the embodiment (ie, modeling information) when the user pushes the moving object 100 through the handle 130 with a greater force for 1 second and releases for 1.5 seconds. 7 is compared with the case where no dynamic information (ie, modeling information) is used as shown in the example (FIG. 8).

The difference in torque components due to the input force for the left / right side is not considered for significant comparison.

Due to the influence of inertia, a difference in speed appeared between the two wheels. Thus, in FIG. 7 (b), a position error between the driving wheels 111a and 111b was shown as a result. At this time, the movable body 100 will rotate about the center of gravity.

Meanwhile, in FIGS. 8A and 8B, dynamic information (that is, modeling information) is used to control the driving wheels 111a and 111b, so that the positional error between the driving wheels 111a and 111b may be reduced. It can be seen that the problem of rotation about the center of gravity caused is solved.

That is, by controlling the drive torque (and the control current for the motor 112a, 112b) for the drive wheels (111a, 111b) by using the dynamic information including the modeling information of the moving object 100 as in the embodiment In addition, the moving object 100 may be stably controlled even when there is a fluctuation caused by the reaction force, and stable control may be performed even when the user exerts a force or releases the moving object 100.

As described above, the description of the technical features described above with reference to FIGS. 1 to 5 may be applied as it is to FIGS. 6 to 8, and thus redundant descriptions thereof will be omitted.

9 is a flowchart illustrating a method of controlling a moving object based on dynamic information associated with the moving object, according to an embodiment.

In FIG. 9, the control method of the moving object 100 described with reference to FIGS. 1 to 8 will be described with reference to a flowchart.

In operation S910, the controller 140 may calculate driving torques for the driving wheels 111a and 111b of the movable body 100 based on the dynamic information associated with the movable body 100. The dynamic information may include predefined modeling information of the moving object 100 and speed information associated with the driving wheels 111a and 111b obtained through the low-level sensors 161a and 161b. The controller 140 may calculate the driving torque for the driving wheels 111a and 111b using the acceleration information obtained based on the modeling information and the speed information.

In operation S920, the controller 140 may calculate a control current for controlling the motors 112a and 112b associated with the driving wheels 111a and 111b of the moving object 100. The controller 140 may generate the control current based on the calculated value of the control current.

In addition, when the external force is applied to the moving object 100, the control unit 140 converts the force information obtained by the force sensors 121 and 122 into acceleration information, and further uses the converted acceleration information to drive wheels 111a. By calculating the drive torque for, 111b), the control current can be calculated / generated.

In operation S930, the controller 140 may control the driving wheels 111a and 111b by controlling the motors 112a and 112b based on the calculated control current. By controlling the driving wheels 111a and 111b based on the calculated control current, the movement error of the movable body 100 due to at least one of the centrifugal force and the inertia generated by the movement of the movable body 100 may be compensated for.

As described above, the description of the technical features described above with reference to FIGS. 1 to 8 may be applied to FIG. 9 as it is, and thus redundant descriptions thereof will be omitted.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the devices and components described in the embodiments may be, for example, processors, controllers, arithmetic logic units (ALUs), digital signal processors, microcomputers, field programmable arrays (FPAs), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to the execution of the software. For the convenience of understanding, a processing device may be described as one being used, but a person skilled in the art will appreciate that the processing device includes a plurality of processing elements and / or a plurality of types of processing elements. It can be seen that it may include. For example, the processing device may include a plurality of processors or one processor and one controller. In addition, other processing configurations are possible, such as parallel processors.

The software may include a computer program, code, instructions, or a combination of one or more of the above, and configure the processing device to operate as desired, or process independently or collectively. You can command the device. Software and / or data may be any type of machine, component, physical device, virtual equipment, computer storage medium or device in order to be interpreted by or to provide instructions or data to the processing device. Or may be permanently or temporarily embodied in a signal wave to be transmitted. The software may be distributed over networked computer systems so that they are stored or executed in a distributed manner. Software and data may be stored on one or more computer readable recording media.

Method according to the embodiment is implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the media may be those specially designed and constructed for the purposes of the embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer readable recording media include magnetic media such as hard disks, floppy disks and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine code, such as produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Although the embodiments have been described by the limited embodiments and the drawings as described above, various modifications and variations are possible to those skilled in the art from the above description. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or even if replaced or substituted by equivalents, an appropriate result can be achieved.

Claims (17)

There is a method of controlling the movement of the moving object,
Calculating a control current for controlling a motor associated with a drive wheel of the mobile body by calculating a drive torque for the drive wheel of the mobile body based on the kinetic information associated with the mobile body; And
Controlling the drive wheel by controlling the motor based on the calculated control current
Including,
The dynamics information includes predefined modeling information of the moving object and speed information associated with the driving wheels obtained through a low-level sensor,
The driving torque is calculated using the acceleration information obtained based on the modeling information and the speed information,
The acceleration information is information indicating an acceleration error occurring when the moving body moves, depending on the position of the motor and the position of the driving wheel in the moving body,
By controlling the driving wheel by the control current, the movement error of the movable body by at least one of the centrifugal force and the inertia generated in accordance with the movement of the movable body is compensated for. The method of claim 1,
The low level sensor is a Hall sensor,
The acceleration information is based on a value estimated by applying a Proportional-Derivative (PD) or Proportional Integral Derivative (PID) controller to position information associated with the moving object estimated based on the integration of the speed information and the speed information. Control method. delete The method of claim 1,
The driving wheel includes a left driving wheel and a right driving wheel,
The drive torque is calculated by Equation 1 as the drive torque for the left drive wheel and the right drive wheel,
[Equation 1]

T _CL is a drive torque for the left drive wheel, T _CR is a drive torque for the right drive wheel, A and B are constants obtained based on the modeling information, respectively, and d is the left side. Distance from the center of the driving wheel and the right driving wheel to the left driving wheel or the right driving wheel, A _x is the acceleration error with respect to the moving displacement x of the moving body, and A _θ is the rotation angle of the moving body A control method for a moving object, which is the acceleration error with respect to θ . The method of claim 1,
And the control current is calculated by dividing the torque constant associated with the drive wheel or the motor by the drive torque. The method of claim 1,
The modeling information,
And the weight of the movable body, the weight of the driving wheel, the radius of the driving wheel, the positional relationship information of the driving wheel relative to the center of gravity of the movable body, and the moment of inertia associated with the movable body. The method of claim 1,
The acceleration information is changed according to the movement of the moving body,
And the driving wheels are continuously controlled using the control current calculated based on the driving torque calculated according to the changing acceleration information. The method of claim 1,
Generating the control current,
When the external force is applied to the movable body, the control information of the movable body is generated by converting the force information obtained by the force sensing sensor into acceleration information and calculating the drive torque using the converted acceleration information further. Way. There is a method of controlling the movement of the moving object,
Calculating a control current for controlling a motor associated with a drive wheel of the mobile body by calculating a drive torque for the drive wheel of the mobile body based on the kinetic information associated with the mobile body; And
Controlling the drive wheel by controlling the motor based on the calculated control current
Including,
The dynamics information includes predefined modeling information of the moving object and speed information associated with the driving wheels obtained through a low-level sensor,
The driving torque is calculated using the acceleration information obtained based on the modeling information and the speed information,
By controlling the driving wheel by the control current, the movement error of the movable body by at least one of the centrifugal force and the inertia generated by the movement of the movable body is compensated for,
Generating the control current,
When the external force is applied to the movable body, the control current is generated by converting the force information obtained by the force sensing sensor into acceleration information and calculating the driving torque using the converted acceleration information further,
The driving wheel includes a left driving wheel and a right driving wheel,
The drive torque is calculated by Equation 2 as the drive torque for the left drive wheel and the right drive wheel,
[Equation 2]

The T _CL is a drive torque for the left drive wheels, the T _CR is a drive torque for the right drive wheels, A and B are constants obtained based on the modeling information, respectively, and the F _L external force. Is a force transmitted to the left driving wheel, F _R is a force transmitted to the right driving wheel among the external forces, and A _a and A _b are constants for converting the external force into acceleration. . A program recorded on a computer-readable recording medium which performs the method of any one of claims 1, 2, and 4-9. In the electrically driven mobile body,
Drive wheels driven by a motor;
At least one low-level sensor for obtaining speed information associated with the drive wheels; And
By calculating a drive torque for the drive wheel based on the kinetic information associated with the moving body, by calculating a control current for controlling the motor associated with the drive wheel, and controlling the motor based on the calculated control current. Control unit for controlling the driving wheel
Including,
The dynamics information includes predefined modeling information of the moving object and the speed information, and the controller calculates the driving torque using the acceleration information obtained based on the modeling information and the speed information.
The acceleration information is information indicating an acceleration error occurring when the moving body moves, depending on the position of the motor and the position of the driving wheel in the moving body,
And the driving wheel is controlled by the control current, thereby compensating for a movement error of the movable body due to at least one of a centrifugal force and an inertia generated according to the movement of the movable body. The method of claim 11,
The low level sensor is a Hall sensor,
The controller estimates the acceleration information based on a value of applying a Proportional-Derivative (PD) or Proportional Integral Derivative (PID) controller to position information associated with the moving object estimated based on the integration of the speed information and the speed information. , Moving object. The method of claim 11,
The drive wheels include a pair of left drive wheels and right drive wheels,
And the control unit calculates the drive torque as drive torque for the left drive wheel and the right drive wheel, respectively. The method of claim 12,
A handle for applying an external force by the user to the movable body; And
Force sensing sensor for measuring the external force applied through the handle portion
More,
The control unit, when the external force is applied to the moving object, converts the force information obtained by the force sensor to the acceleration information, and further calculates the drive torque using the converted acceleration information. The method of claim 11,
Manual wheel configured to rotate according to the movement of the movable body without driving by the power, the direction is adjusted according to the moving direction of the movable body
The moving body further comprising. The method of claim 11,
Loading section for loading the goods to be transported
The moving body further comprising. The method of claim 11,
And the control unit continuously controls the drive wheels using the control current calculated by calculating the drive torque in accordance with the acceleration information that changes with the movement of the mover.

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