JP2007245244A - Movable body controlling system and absolute position calculating method for moving part of movable body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a movable body controlling system which precisely calculates the absolute position of a moving part of a movable body. <P>SOLUTION: The movable body controlling system including the movable body and a device to transmit signals containing the transmission time information, is equipped with: the main body; the moving part; an actuator to drive the moving part; a signal reception part mounted on the main body and receiving the signals; a position calculating part to calculate the absolute position of the signal reception part from the signals, a driving amount sensing part for the actuator; and a functional part to calculate the absolute position of the moving part from the position information calculated by the position calculating part and the driving amount obtained through sensing. The absolute position calculating part is equipped with: a timer; a memory part to store both the driving amount sensed and the sensing time; a specifying part to specify the driving amount at the point when a signal is transmitted from the transmitting time information out of the memory part; and a calculation part to calculate the absolute position of the moving part at the time of transmitting the signal, from the driving amount and the position information calculated by a main body position calculating device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a signal transmission device and a moving body control system including a moving body that moves in space.

A moving body control system that controls a moving body while recognizing the position of the moving body by a position detection system such as GPS is known. This type of moving body control system includes a moving body and a signal transmission device that transmits a signal to a space in which the moving body moves. The moving body includes a main body, a movable unit coupled to the main body via a joint, an actuator that drives the joint, a signal receiving unit that receives a signal transmitted from the signal transmission device to the space, and a signal receiving unit that receives the signal. A main body position calculation unit that calculates the absolute position of the signal receiving unit (hereinafter referred to as the absolute position of the main body) from the signal and a drive amount detection unit that detects the drive amount of the actuator. The moving body drives the joint by the actuator while moving in the space, and moves the movable part. Or it moves in space by driving a joint and moving a movable part.
In such a moving body, the absolute position of the movable part is calculated in order to cause the movable part to perform a desired motion. The absolute position of the movable unit is calculated using the absolute position of the main body calculated by the main body position calculating unit and the driving amount detected by the driving amount detecting unit. That is, the relative position of the movable part with respect to the main body is calculated from the drive amount of the actuator, and the absolute position of the movable part is calculated from the calculated relative position of the movable part and the absolute position of the main body.
A moving body that detects the absolute position of the main body using the above-described signal is disclosed in Patent Document 1.

JP 2004-17248 A

In the mobile body control system described above, a short time t is required between the time when the signal reception unit receives the signal and the time when the absolute position of the main body is calculated. That is, the absolute position of the main body calculated from the received signal is the absolute position of the main body at time t before the calculated time. Therefore, when the main body is moving, the actual position of the main body at the timing when the absolute position of the main body is calculated is slightly different from the calculated absolute position of the main body. For this reason, even if the absolute position of the movable part is calculated based on the calculated absolute position and the driving amount of the actuator at the time of calculation, the calculated absolute position is not a correct absolute position. If the absolute position of the movable part cannot be accurately calculated, there arises a problem that the movable part cannot be moved accurately.
For example, in a moving body in which a leg portion is configured by a movable portion connected to a main body via a joint and moves to a target position by driving the leg portion, control may be performed based on the position of the leg portion. However, as described above, if a time difference occurs in the calculation of the absolute position of the main body, the absolute position of the leg is not accurately calculated. Therefore, although it is determined that the leg has not reached the target position even though the leg has actually reached the target position, the leg is further driven. Therefore, the moving body cannot be stopped at the target position.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a moving body control system that moves a movable portion of a moving body with high accuracy.

The mobile body control system of the present invention includes a mobile body that moves in a space, and a signal transmission device that transmits a signal including time information indicating a transmission time to the space. The moving body includes a main body, a movable part coupled to the main body via a joint, an actuator that drives the joint, a signal receiving unit that is attached to the main body and receives a signal transmitted to the space by the signal transmission device, A body position calculation unit that calculates an absolute position of the signal reception unit from a signal received by the signal reception unit, a drive amount detection unit that detects the drive amount of the actuator, and position information and drive amount detection unit that are calculated by the body position calculation unit An absolute position calculation unit that calculates the absolute position of the movable part from the driving amount of the actuator detected in step (b). The absolute position calculation unit includes a timer that measures the time when the drive amount of the actuator is detected by the drive amount detection unit, and a detection that the timer detects the drive amount of the actuator that is detected by the drive amount detection unit at a predetermined time interval. Based on the storage unit that sequentially stores with time and the transmission time information of the signal corresponding to the position information calculated by the main body position calculation unit, the drive amount of the actuator at the time when the signal is transmitted is stored in the storage unit. The absolute position of the movable part at the time of transmitting the corresponding signal is calculated from the drive amount specifying unit specified from the drive amount, the position information calculated by the main body position calculating unit, and the drive amount specified by the drive amount specifying unit. A movable part position calculation unit is provided.
In this moving body control system, the drive amount of the actuator detected by the drive amount detection unit is stored in the storage unit in order along with the detection time. The signal transmission device transmits a signal including transmission time information, and the signal is received by the signal receiving unit. Since the signal transmitted by the signal transmission device is received by the signal receiving unit almost simultaneously with transmission, the signal transmission time information indicates the signal reception time. The main body position calculation unit calculates the absolute position of the signal reception unit based on the signal received by the signal reception unit. Then, the actuator at the time when the drive amount specifying unit receives those signals from the drive amounts stored in the storage unit using the transmission time information of the signal corresponding to the position information calculated by the main body position calculation unit as a key. Specify the drive amount. Thereby, the driving amount of the actuator at the same time as the signal reception time is specified. The movable part position calculating unit specifies the position of the movable part from the position information calculated by the main body position calculating unit and the drive amount specified by the drive amount specifying unit. Therefore, the absolute position of the movable part at the time of receiving the signal can be calculated with high accuracy.

  In the above-described mobile body control system, the absolute position calculation unit may further include a correction unit that corrects a deviation between the time measured by the timer and the time information included in the signal transmitted from the signal transmission device. preferable. By correcting the deviation between the time measured by the timer and the time information included in the signal, the absolute position of the movable part can be calculated with higher accuracy.

As a method for correcting the deviation between the time measured by the timer and the time information included in the signal, for example, the following method can be employed.
That is, the correction unit calculates the absolute position of the signal receiving unit by the main body position calculation unit at a predetermined time interval while operating the main body in a preset operation pattern, and calculates the operation performed on the main body and the main body position. The deviation between the time measured by the timer and the time information included in the signal transmitted from the signal transmission device is corrected from the deviation from the absolute position orbit of the signal reception unit calculated by the unit. According to this method, the deviation between the two can be corrected by a simple method.

The absolute position of the movable part calculated by the absolute position calculation unit described above is the absolute position at the time when the position information is transmitted (that is, the absolute position of the movable part before a predetermined time t from the current time). Therefore, it is preferable that the absolute position calculation unit further includes a predicted position calculation unit that predicts the current absolute position of the movable unit based on the absolute position of the movable unit calculated by the movable unit position calculation unit. By predicting the current absolute position based on the past accurate absolute position, the current absolute position can be predicted with high accuracy.
As a method of predicting the current absolute position, the current absolute position can be calculated based on the absolute position calculated by the movable part position calculating part and the movement command values to the main body and the movable part from that point to the present. .

The present invention also provides an absolute position calculation method capable of suitably calculating the absolute position of the movable part. That is, the absolute position calculation method of the present invention detects a main body, a movable part coupled to the main body via a joint, an actuator that drives the joint, a signal receiving part that receives a signal, and a driving amount of the actuator. Transmitting a signal including transmission time information to a signal receiving unit, a movable body that freely moves in a space provided with a driving amount detection unit that performs time measurement, a timer that measures time, and a storage unit that stores data In a moving body control system including a signal transmission device, an absolute position of a movable portion of the moving body is calculated. In this method, a step for storing the drive amount of the actuator detected by the drive amount detection unit together with the detection time in a storage unit in order at a predetermined time interval, and a signal including time information indicating the transmission time from the signal transmission device. A signal is received based on the transmission time information of the signal received by the signal receiving unit, the step of calculating the absolute position of the signal receiving unit from the received signal, and the signal received by the signal receiving unit A step of specifying the drive amount of the actuator at the time from among the drive amounts stored in the storage unit, a step of calculating the absolute position of the movable unit from the calculated absolute position of the signal receiving unit and the specified drive amount Have
According to this method, the absolute position of the movable part can be calculated with high accuracy.

The main features of the embodiments described in detail below are listed first.
(Mode 1) The robot control system includes a robot, a GPS signal output device, and a plurality of GPS antennas.
(Mode 2) The GPS signal output device includes a time counting unit that counts time, and the GPS signal output device outputs a signal including transmission time information counted by the time counting unit to each GPS antenna. Simultaneously, GPS radio waves including transmission time information are transmitted from the respective GPS antennas.
(Mode 3) The robot is attached to the head, the first movable part attached to the head, the second movable part attached to the first movable part,... The nth movable part is provided. The head and the first movable part are connected by joints, and the movable parts are also connected by joints. By driving each joint, each movable part connected by the joint moves relatively.
(Form 4) A leg part is comprised by a part of movable part group, and a robot walks by driving the joint of a leg part.
(Mode 5) A GPS sensor (GPS receiver) is installed on the head.
(Mode 6) The GPS sensor receives GPS radio waves, and detects the absolute position of the GPS sensor itself by analyzing the received GPS radio waves. The data transmitted by the GPS radio wave includes time data when the GPS radio wave is transmitted. The GPS sensor outputs the detected absolute position and time data.
(Mode 7) Each joint has a motor. When the joint is driven by the motor, the movable part connected by the joint moves.
(Mode 8) Each motor has an encoder, and the encoder detects the rotation angle of the motor.
(Mode 9) The robot has a control device. The control device is electrically connected to the GPS sensor, each encoder, and each motor.
(Mode 10) The control device includes a coordinate calculation unit that calculates the absolute position of the foot. The coordinate calculation unit calculates the absolute position of the tip of the foot from the absolute position and time data of the GPS sensor output from the GPS sensor and the detection value of each encoder.
(Mode 11) The control device outputs a control command value to the motor based on the detected value of each encoder and the absolute position of the tip of the foot calculated by the coordinate calculation unit, and causes the robot to walk.
(Mode 12) The coordinate calculation unit includes a timer that counts time, a first reading unit that reads the absolute position and time data of the main body output from the GPS sensor, and the detection time of each encoder while reading the detection value of each encoder The storage unit stores the second reading unit that is measured in Step 1, the storage unit that stores the detection value read by the second reading unit in association with the detection time, and the time data read by the first reading unit as keys. Among the detection values, a specifying unit for specifying a detection value associated with the time data closest to the time data, a movable unit based on the absolute position read by the first reading unit and the detection value specified by the specifying unit The calculation part which calculates absolute position of is provided.

  A robot control system 100 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the robot control system 100 includes a robot 10, a GPS signal output device 102, and four GPS antennas (so-called indoor GPS satellites) 104a to 104d.

  As shown in FIG. 1, a plurality of GPS antennas 104 a to 104 d are attached around the field where the robot 10 moves. The GPS antennas 104 a to 104 d are connected to the GPS signal output device 102. The GPS signal output device 102 includes a time counting unit 106 that counts time t. The GPS signal output device 102 reads the time information t counted by the time counting unit 106 and outputs an electrical signal (GPS signal) including the time information t to the GPS antennas 104a to 104d. Then, each GPS antenna 104a-104d transmits simultaneously the electromagnetic wave (GPS electromagnetic wave) which converted the input GPS signal to the space which a robot moves. Accordingly, GPS radio waves including time information t are transmitted to the space in which the robot moves. Since the GPS signal output device 102 repeatedly outputs GPS signals at a predetermined cycle, GPS radio waves are repeatedly transmitted at a predetermined cycle to the space in which the robot moves. In addition, since the processing from when the GPS signal output device 102 reads the time information t to when the GPS antennas 104a to 104d transmit GPS radio waves is performed almost simultaneously, the time information t indicates the time when the GPS radio waves are transmitted. Yes.

The robot 10 is an autonomous mobile robot that is arranged on a flat floor surface and moves while walking to a target position on the floor surface.
As shown in FIG. 1, the robot 10 includes a head 12, a torso part 14, thigh parts 16 and 18, shin parts 20 and 22, and foot parts 24 and 26. The head 12 and the body 14 are connected by a joint 30. The body part 14 and the thigh part 16 are connected by joints 32 and 34. The thigh 16 and the shin 20 are connected by a joint 36. The shin part 20 and the foot part 24 are connected by a joint 38. The body part 14 and the thigh part 18 are connected by joints 40 and 42. The thigh 18 and the shin 22 are connected by a joint 44. The shin part 22 and the foot part 26 are connected by a joint 46. A right leg 50 is formed by the thigh 16, the shin 20, the foot 24, and the joints 32, 34, 36, and 38. A left leg 52 is formed by the thigh 18, the shin 22, the foot 26, and the joints 40, 42, 44, and 46.
Each joint is provided with a motor (not shown). By driving the motor, each joint is driven, and the angle of each joint is changed. Each motor has an encoder, and the encoder detects joint angles φ _{1 to} φ ₉ by detecting the rotation amount of the motor. As shown in FIG. 3, each motor and each encoder are connected to a control device 60 described later.

FIG. 2 is a diagram schematically showing the position of each joint and the rotation axis of each joint. In FIG. 2, the positions of the joints are indicated by points 30 to 46. Further, the tips 24a and 26a of the feet 24 and 26 are indicated by points 24a and 26a. Further, the position of the vertex 12a of the head 12 to which the GPS sensor 58 described later is attached is indicated by a point 12a. The relative position of each point is indicated by vectors l _{1 to} l ₁₁ . As shown in FIG. 2, the joints 30 to 46 rotate in directions of angles φ _{1 to} φ ₉ , respectively. The encoder of each joint detects each of the angles of engagement φ _{1 to} φ ₉ .

The robot 10 includes a GPS sensor 58 that receives GPS radio waves. The GPS sensor 58 is attached to the apex 12 a of the head 12. The GPS sensor 58 receives GPS radio waves (that is, GPS signals) transmitted from the respective GPS antennas 104a to 104d, and the GPS sensor 58 itself (that is, the vertex 12a of the head 12) is absolute based on the received GPS signals. Position A is detected. The GPS sensor 58 reads time information t included in the received GPS signal. As described above, since the GPS radio wave is repeatedly transmitted at a predetermined cycle, the GPS sensor 58 repeatedly receives the GPS signal at a predetermined cycle, and detects the absolute position A and the time information t. The GPS sensor 58 is connected to a control device 60 described later, and outputs the detected absolute position A and time information t to the control device 60.
In order for the GPS sensor 58 to detect (calculate) the absolute position A based on the received GPS signal, it is necessary to calculate the absolute position A by analyzing the GPS radio waves transmitted from the GPS antennas 104a to 104d. is there. Therefore, it takes a certain time until the absolute position A is detected after receiving the GPS signal. Since the procedure for calculating the absolute position A from the received GPS signal is well known in the art, detailed description thereof is omitted here.

The robot 10 includes a control device 60 that controls the motors of the joints 30 to 46. As shown in FIG. 3, the control device 60 is connected to a GPS sensor 58, a motor that drives each of the joints 30 to 46, and an encoder of the motor. The control device 60 is constituted by a microcomputer if it includes a CPU, ROM, RAM, and the like. The control device 60 executes a program stored in the ROM, thereby (1) outputting a torque command value to the motors of the joints 30 to 46 to drive the joints 30 to 46; coordinate calculating 2) and an absolute position a and the time data t outputted from the GPS sensor 58, the detected value phi ₁ to [phi] ₁₁ input from the encoder of the joints 30 to 46, the tip portion 24a, the absolute position of 26a It functions as the calculation unit 70.

  First, the configuration of the coordinate calculation unit 70 will be described. The coordinate calculation unit 70 includes a time counting unit 72, a storage unit 76, a data specifying unit 78, a calculation unit 80, a predicted position calculation unit 82, and a shaft foot determination unit 84.

The shaft foot determination unit 84 determines which of the right leg portion 50 and the left leg portion 52 is the shaft foot (that is, the leg portion to which the weight of the robot 10 is added more). Absolute position data AM _ti and AP _ti of the tip portions 24a and 26a of the foot portions 24 and 26 and absolute position data A _ti of the vertex 12a of the head 12 are input to the axial foot determination unit 84 from a calculation unit 80 described later. Is done. The shaft foot determination unit 84 determines which one is the shaft foot from the absolute position data of the tip portions 24a and 26a and the vertex 12a that are input. The determination value of the pivot foot determination unit 84 is input to the calculation unit 80.

  The time counting unit 72 counts time. The time data s counted by the time counting unit 72 is set to be substantially the same as the time data t counted by the time counting unit 106 of the GPS signal output device 102 described above. The time data s counted by the time counting unit 72 is read into the storage unit 76.

The storage unit 76 reads and stores the joint angles φ _{1 to} φ ₉ of the joints 30 to 46 from each encoder at a predetermined cycle. The storage unit 76 reads the time data s of the time counting unit 72 when reading the joint angles φ _{1 to} φ ₉ from each encoder, and stores the read angle data φ _{1 to} φ ₉ in association with the time data s.
The period for reading the joint angles φ _{1 to} φ ₉ of the joints 30 to 46 from the encoder is set shorter than the period from when the GPS signal is received by the GPS sensor 58 until the absolute position is output. . FIG. 6 schematically shows the relationship between the cycle for reading the joint angles φ _{1 to} φ ₉ and the cycle for outputting the absolute position by the GPS sensor 58. As shown in FIG. 6, while outputting the absolute position from the GPS sensor 58 once, the joint angles φ _{1 to} φ ₉ of the encoder are read a plurality of times and stored in the storage unit 76.

When the absolute position A and the time data t are input from the GPS sensor 58, the data specifying unit 78 uses the time data t as a key from the angle data stored in the storage unit 76, from the GPS sensor 58. The angle data corresponding to the output absolute position A is specified.
That is, the data specifying unit 78 receives the time data t _i and the absolute position data A _ti of the vertex 12a at the time t _i from the GPS sensor 58 at a predetermined cycle. Data identifying unit 78, is input to the time data t _i, searches the time data s storage unit 76 stores, for identifying a nearest time data s _n and the input time data t _i. Then, read the angle data phi ₁ to [phi] ₉ associated with time data s _n where specified. Further, the data identification unit 78, the reading angle data phi ₁ to [phi] ₉ from the storage unit 76, the read angle data phi ₁ to [phi] ₉ stored before the angle data phi ₁ to [phi] ₉ and time data s Erase. The read angle data φ _{1 to} φ ₉ and the absolute position data A _ti input from the GPS sensor 58 are input to the calculation unit 80.

The calculation unit 80 (1) the relative positions M _ti , P of the feet 24 and 26 (specifically, the tip portions 24a and 26a) with respect to the head 12 from the angle data φ _{1 to} φ ₉ specified by the data specifying unit 78. calculates _ti, (2) the calculated tip 24a, from the absolute position _{a ti} of the output head 12 from the relative positions and the GPS sensor 58 26a, the tip portion 24a, the absolute position _AM ti of 26a, _{AP ti} Is calculated.
That is, the absolute position data A _ti and the angle data φ _{1 to} φ ₉ are input to the calculation unit 80 from the data specifying unit 78 at a predetermined cycle. Calculating section 80, each time the data from the data identification unit 78 is input, the tip portion 24a at time _{t i} from the data input, the absolute position _AM ti of 26a, calculates _{AP ti.}

(1) the angle data phi ₁ to [phi] ₉ from the tip portion 24a, first, calculation of the relative position of 26a, the angle data phi ₁ to [phi] ₉ from the tip portion 24a, a method for calculating the relative position of 26a will be described. First, the coordinate axes in the robot will be described, and then the procedure for calculating the relative position will be described.

(Setting of robot coordinate axes)
The basic posture of the robot 10 is set to a posture in which the joint shown in FIG. 4 is extended. Also, an x′y′z ′ coordinate system (the coordinate system of the robot 10) is set such that the front direction of the robot 10 is the x ′ axis, the vertical direction is the z ′ axis, and the direction perpendicular to the x ′ axis and the z ′ axis is the y ′ axis. ) Is set.
The position of each point (joint 30 to 46, the apex 12a, the tip portion 24a, 26a) is defined by the relative position vector _l 1 _{to l 11.} Vectors l _{1 to} l ₁₁ indicate the relative positions of downstream points adjacent to each point (the vertex 12a side is the upstream side). l _{1 to} l ₁₁ are constants determined by the dimensions of each part of the robot 10. For example, the relative position of the point 26a with respect to the point 46 in the basic posture is defined by the vector l ₁₁ = (0, 0, l ₁₁ ). Further, the angles φ _{1 to} φ ₉ of the joints 30 to 46 are defined by the angles with respect to the basic posture.
Under the above setting, the points 24a, the relative position at time _{t i} of 26a (relative position data _{M ti, P ti)} is calculated in place.

(Calculation of relative position in the coordinate system of the head 12)
Relative position _{M 6} for the point 38 of the point 24a in FIG. 2, the vector _l to ₆ direction _{z 6-axis, y 6} axis direction of the rotation axis of the joint 38, _{x 6} axis direction orthogonal to the _{z 6} axis and _{y 6} axes defined by the the _{x 6 y} 6 _z 6 coordinate system (the coordinate system of the foot 24). Accordingly, the relative position M ₆ of the point 24a with respect to the point 38 is (0, 0, l ₆ ). _Then, x ₆ y 6 _z relative position _{M 6} points 24a, shown in ₆ coordinate system, _{y 5-axis} the rotation axis direction of the vector _{l 5} direction _{z 5-axis,} the joint 38, _{z 5-axis} and y relative position _M 5 in _5-axis and the direction perpendicular to the _{x 5} -axis _x 5 _y 5 _{z 5} coordinate system (the coordinate system of the leg portion _{20) (x m5, y m5} , z m5) to coordinate transformation. The relative position M ₅ is obtained by rotating the vector M ₆ about the rotation axis y ₅ by an angle φ ₅ . That is,

Here, Rot (y ₅ , φ ₅ ) is a rotation vector that rotates a predetermined coordinate system by φ ₅ around the y ₅ axis. _Thus, the relative positions _{M 5} for the point 38 of the point 24a in ₅ y 5 _{z 5} coordinate system x are calculated.
Next, the relative position _{M 5} calculated, the same _{x 5 y} 5 _z 5 position relative to the point 36 in the coordinate system _{M 5 '(x m5',} y m5 ', z m5') to coordinate conversion. Since the relative position M ₅ ′ is a coordinate obtained by sliding the relative position M ₅ by the vector l ₅ minutes,

As a result, the relative position M ₅ ′ of the point 24 a with respect to the point 36 in the x ₅ y ₅ z ₅ coordinate system is calculated. By repeating such coordinate transformation for each point toward the upstream side, the vector l ₁ direction is set to the z ₁ axis, and the rotation axis direction of the joint 30 is set to the x ₁ axis, the x ₁ axis, and the z ₁ axis. The relative position M ₁ ′ (x _m1 ′, y _m1 ′, z _m1 ′) of the point 24a with respect to the point 12a in the x ₁ y ₁ z ₁ coordinate system (coordinate system of the head 12) with the orthogonal direction as the y ₁ axis. Is calculated. That is,

Similarly, the relative position P ₁ ′ of the point 26a with respect to the point 12a is also calculated.

(Calculation of posture angle of head 12)
Next, the calculation unit 80 reads the current shaft foot from the shaft foot determination unit 84. Then, the posture angle of the head 12 is calculated from the angles of the joints 30 and the joints 30 of the shaft foot.
That is, the foot part (grounding foot) on the shaft foot side is parallel to the floor surface. Therefore, the posture angle of the head 12 can be obtained from the joint angle from the foot on the axial foot side to the head 12. As shown in FIG. 5, the posture angle of the head 12 is indicated by an inclination angle phi _0y at an inclination angle phi _0x and y 'around the axis of about axis' x of the axis' vector l ₁ and z. For example, as shown in FIG. 2, when the leg part 52 is a shaft foot, it calculates with the following formula | equation.

(Calculation of relative position in the coordinate system of the robot 10)
Next, from the vector M ₁ ′, the vector P ₁ ′, the angle φ _0x and the angle φ _0y , a relative position M ₀ (relative to the point 12a of the point 24a in the x′y′z ′ coordinate system (the coordinate system of the robot 10)). x _m0 , y _m0 , z _m0 ) and the relative position P ₀ (x _p0 , y _p0 , z _p0 ) of the point 26 a with respect to the point 12 a in the x′y′z ′ coordinate system are calculated. The relative positions M ₀ and P ₀ are calculated by converting the coordinates of the relative positions M ₁ ′ and P ₁ ′ with the angles φ _0x and φ _0y . That is,

The calculated relative positions M ₀ and P ₀ are the relative positions M _ti and P _ti of the tips 24a and 26a with respect to the head 12.

(2) Calculation of absolute position of tip portions 24a and 26a First, the calculation unit 80 advances the robot 10 from the input absolute position data A _ti and the absolute position data A _ti-1 input in the previous processing cycle. Calculate the direction. The traveling direction of the robot 10 can be represented by an angle θ with respect to the x axis.
When the angle θ is calculated, the calculating unit 80 converts the relative position data M _ti and P _ti in the x′y′z ′ coordinate system into the absolute position data AM _ti and AP _ti of the end portions 24a and 26a in the xyz coordinate system. To do. The absolute position data AM _ti and AP _ti are obtained by rotating the relative position data M _ti and P _ti by an angle θ around the z axis and sliding the absolute position data A _ti by the absolute position data A _ti . That is,

The absolute position data AM _ti and AP _ti of the tip portions 24 a and 26 a calculated by the calculation unit 80 are input to the predicted position calculation unit 82. Further, the absolute position data AM _ti and AP _{ti of} the tip portions 24 a and 26 a and the absolute position data A _ti axis foot determining unit 84 of the vertex 12 a are input.

The predicted position calculation unit 82 predicts the absolute positions of the tip portions 24a and 26a of the current foot portions 24 and 26 from the calculated absolute position data AM _ti and AP _ti .
That is, the absolute position data AM _ti and AP _ti are input to the predicted position calculation unit 82 at a predetermined cycle. The predicted position calculation unit 82 _reads , from the control unit 62, the movement command value output to each motor from the time when the tip portions 24a and 26a are in the absolute position data _AMti and _APti to the present. Then, from the relative movement values of the tip portions 24a and 26a predicted from the read movement command value and the input absolute position data AM _ti and AP _ti , the absolute positions AM ₀ and AP ₀ of the current tip portions 24a and 26a are obtained. Predict.
The absolute position data AM ₀ and AP ₀ predicted by the predicted position calculation unit 82 are input to the control unit 62.

  The time data synchronization unit 86 inputs control data to the control unit 62 to cause the robot 10 to execute a specific operation, and reads the absolute position data A and time data t input from the GPS sensor 58. Then, based on the motion trajectory of the vertex 12a of the head 12 calculated from the joint angle and the motion trajectory of the vertex 12a calculated from the absolute position data A input from the GPS sensor 58, the time count of the GPS signal output device 102 is counted. The time data t counted by the unit 106 and the time data s counted by the time counting unit 72 are synchronized.

The control unit 62 includes absolute positions AM ₀ and AP _{0 of} the tips 24a and 26a predicted by the predicted position calculation unit 82, joint angles φ _{1 to} φ ₉ input from the encoders, and target position coordinates input separately. Based on (that is, target trajectory data), a torque command value to be output to each motor is calculated. Specifically, the control unit 62 firstly shifts the absolute positions AM ₀ and AP _{0 of} the tip portions 24a and 26a predicted by the predicted position calculation unit 82 from the target positions of the tip portions 24a and 26a based on the target trajectory data. The target position to be output next is corrected. Based on the corrected target position and the joint angles φ _{1 to} φ ₉ input from each encoder, a torque command value to be output to each motor is calculated. The calculated torque command value is output to each motor.
In addition, about the procedure which calculates the torque command value which the control part 62 outputs to each motor, since a conventionally well-known method can be used, it abbreviate | omits here for the detailed description.

Next, an absolute position calculation process executed by the control device 60 described above will be described. FIG. 7 is a flowchart showing the absolute position calculation process of the control device 60.
The controller 60 as shown in FIG. 7 first determines whether the absolute position data _{A ti} and time data _{t i} is inputted from the GPS sensor 58 (Step S2). If there is no data input from the GPS sensor 58 (NO in step S2), the control device 60 ends the process as it is. If there is data input from the GPS sensor 58 (YES in step S2), the process proceeds to step S4.

In step S4, the control unit 60 as a key time data _{t i} input from the GPS sensor 58, of the angle data phi ₁ to [phi] ₉ in the storage unit 76 is stored, the time data _{t i} input And corresponding angle data φ _{1 to} φ ₉ are read (step S4). That is, to identify the nearest time data s _n to the time data t _i that is input, reads out the angle data phi ₁ to [phi] ₉ associated with the time data s _n.
Reading the angle data phi ₁ to [phi] _9, the controller 60 erases the angle data phi ₁ to [phi] ₉ stored in the storage unit 76 of the time before the time data t _i input (step S6) . Thereby, unnecessary data is erased from the storage unit 76.

Next, the control device 60 acquires information indicating which shaft foot is from the shaft foot determination unit 84 (step S8), and the acquired shaft foot information and the angle data φ _{1 to} φ input in step S4. ₉ , the relative position data M _ti and P _ti of the tips 24a and 26a of the feet 24 and 26 with respect to the vertex 12a of the head 12 are calculated (step S10). The procedure for calculating the relative position data M _ti and P _ti has already been described.

When the relative position data M _ti and P _ti are calculated, the control device 60 calculates the absolute position data A _ti input from the GPS sensor 58 input in step S2 and the relative position data M _ti and P _ti calculated in step S10. Based on the above, the absolute positions AM _ti and AP _ti of the tips 24a and 26a of the feet 24 and 26 are calculated (step S12). Next, based on the absolute positions AM _ti and AP _ti calculated in step S12 and the movement command value output from the control unit 62, the control device 60 determines the current positions of the distal end portions 24a and 26a of the foot portions 24 and 26. The absolute positions AM ₀ and AP ₀ are predicted (step S14). Thereby, the process of the control device 60 is terminated.

Next, time data synchronization processing executed by the control device 60 will be described. FIG. 9 is a flowchart showing a time data synchronization process executed by the control device 60 in order to synchronize the time count unit 72 of the coordinate calculation unit 70 and the time count unit 106 of the GPS signal output device 102.
As shown in FIG. 8, when the time data synchronization process is started, the control device 60 first stands the robot 10 upright (step S36), and the initial position A _p (x _p , y _p ) is acquired (step S38). That is, the control device 60 stands by until the absolute position data of the head 12 is output from the GPS sensor 58. When the absolute position data is output from the GPS sensor 58, the output absolute position data is converted to the initial position A. Store as _p .

When the process proceeds to step S40, the control device 60 outputs a control command value to the motor of the joint 30, and causes the robot 10 to swing in a constant cycle (step S40). In parallel as to the swinging motion to the robot 10, the controller 60 sequentially obtains the absolute position data _{A ti} and time data _{t i} output from the GPS sensor 58 (step S42). In parallel with the data acquisition in step S42, the control device 60, with sequentially reads the angle phi ₁ of the joint 30, and acquires the read time _{s n} (step S44).
Next, the control unit 60 plots the y-coordinate _{y ti} of absolute position data _{A ti} are sequentially acquired in step S42, the time data _{t i} in the graph (see FIG. 10, step S46). Further, the control device 60 from the initial position of the acquired head 12 at the joint angle phi ₁ and step S38 are sequentially obtained in step S44, the y-coordinate _{y sn} head 12 at time _{s n} from the following formula calculate. Note that θ in the following expression is an angle between the orientation of the robot 10 and the x axis. Y-coordinate _{y sn} and time data _{s n} of the calculated head 12 are plotted in the graph (step S48).

When the motion trajectory of the head 12 based on the GPS sensor 58 is plotted in step S46 and the motion trajectory of the head 12 based on the detection result of the encoder is plotted in step S48, the control device 60 determines that the y coordinate y _ti is The y coordinate y _sn is compared, and the difference between the time data t and the time data s is calculated (step S50). That is, since the robot 10 is only swinging in an upright state, the head 12 based on the motion trajectory of the head 12 of the robot 10 detected by the GPS sensor 58 and the joint angle φ ₁ detected by the encoder. The motion trajectories should be consistent. Therefore, the time deviation Δt (Δt in FIG. 10) between the y-coordinate y _{ti of the} head 12 based on the GPS sensor 58 and the y-coordinate y _sn of the head 12 based on the encoder is determined by the GPS signal output device 102. There is a time lag between the time count unit 106 and the time count unit 72 in the control device 60. Therefore, the control device 60 corrects the time data s of the time counting unit 72 in the control device 60 according to the deviation time Δt calculated in step S50 (step S52). Thereby, the time data t of the GPS signal output device 102 and the time data s in the control device 60 can be accurately synchronized.

As described above, in the robot control system 100 of the present embodiment, when the GPS sensor 58 receives the GPS signals, GPS sensor 58, the time information _{t i} contained in the GPS signal, is calculated from the GPS signal The absolute position is output to the control device 60. In the control unit 60, along with reading the angle phi ₁ to [phi] ₉ of each joint which each encoder detects, it stores the read time s _n to the reading memory section 76. When the control device 60 calculates the absolute positions of the tip portions 24a and 26a of the feet 24 and 26, the GPS received by the GPS sensor 58 from the angle data φ _{1 to} φ _{9 in} the storage unit 76. identifying the angular data phi ₁ to [phi] ₉ corresponding to the time information t _i contained in the signal. Then, the control unit 60 calculates the absolute position data output from the GPS sensor 58, the angle data phi ₁ to [phi] ₉ that specified, the tip portion 24a of the legs 24 and 26, the absolute position of 26a. Therefore, the control device 60 can accurately calculate the absolute positions of the tip portions 24a and 26a.
Further, in the robot control system 100 according to the present embodiment, the joint 30 is driven to cause the head 12 of the robot 10 to swing in a state where the legs 50 and 52 of the robot 10 are not moved with respect to the floor surface. . Then, the absolute position output from the GPS sensor 58 is detected at a predetermined cycle while performing a swing motion, and the angle φ _{1 of the} joint 30 is read to calculate the y coordinate y _sn of the head 12. Then, the y-coordinate y _{sn of the} head 12 based on the GPS sensor 58 is compared with the y-coordinate y _ti of the head 12 based on the detection value of the encoder to calculate the time difference t between the time data t and the time data s. . Thereby, the absolute position can be calculated with high accuracy.
Further, in the robot control system 100 of the present embodiment, the absolute position of the current distal end portions 24a and 26a is predicted from the absolute position of the distal end portions 24a and 26a calculated by the control device 60, and based on the predicted absolute position. Correct the trajectory data. For this reason, the robot 10 can accurately walk on the target trajectory and stop accurately at the target position.

In the embodiment described above, on the basis of the time data t _i and s _n, although GPS radio waves specified angle data phi ₁ to [phi] ₉ when it is transmitted, the present invention is not limited to such an embodiment . For example, the delay time from the reception of the GPS radio wave by the GPS sensor 58 to the output of the absolute position is measured in advance, and the angle data φ _{1 to} φ ₉ when the GPS radio wave is transmitted is specified based on the delay time May be.
In the embodiment described above, the angle data φ _{1 to} φ ₉ is stored in the storage unit 76, but the present invention is not limited to such a form. For example, the control device 60 calculates the relative position data M _ti and P _ti from the detected joint angles φ _{1 to} φ ₉ and stores the calculated relative position data M _ti and P _ti in the storage unit. Good.
In the above-described embodiment, y _sn and y _ti are calculated and compared in the time data synchronization process, but the present invention is not limited to such a form. For example, by plotting the joint angle φ ₁ and the y-coordinate y _ti on a graph, the deviation time Δt can be obtained from the phase shift of these trajectories. That is, to calculate the other type of data that indicates the position change of the apex 12a from the detected value and the joint angles phi ₁ of the GPS sensor, time data by comparing them can be synchronized.
In the above-described embodiment, the time data is synchronized by driving only the joint 30 while the robot 10 is standing upright, but various other operations are performed without moving the feet 24 and 26. Thus, the time data can be synchronized.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

1 is an overall view of a robot control system 100 of the present embodiment. Explanatory drawing of the robot 10 of a present Example. The block diagram of the robot 10 of a present Example. Explanatory drawing of the robot 10 of a present Example. Explanatory drawing of the attitude | position angle of the head 12 of the robot 10 of a present Example. Explanatory drawing of the absolute position of the head 12, and the detection timing of a joint angle. The flowchart of the absolute position calculation process of the leg parts 24 and 26. The flowchart of a time data synchronous process. Diagram showing movement trajectory deviation during time data synchronization processing

Explanation of symbols

10: Robot 12: Head 12a: Vertex 14: Body part 16, 18: Thigh part 20, 22: Tibial part 24, 26: Foot part 24a, 26a: Tip part 30-46: Joint 50: Right leg part 52: Left leg 58: GPS sensor 60: control device 62: control unit 70: coordinate calculation unit 72: time counting unit 76: storage unit 78: data specifying unit 80: calculation unit 82: predicted position calculation unit 84: shaft foot determination unit 86: Time data synchronization unit 100: Robot control system 102: GPS signal output devices 104a to 104d: GPS antenna 106: Time count unit

Claims (5)

A moving body control system comprising a moving body that moves in space, and a signal transmission device that transmits a signal including time information indicating a transmission time to the space,
The moving body
The body,
A movable part coupled to the body via a joint;
An actuator that drives the joint;
A signal receiving unit that is attached to the main body and receives a signal transmitted from the signal transmission device to the space;
A main body position calculation unit that calculates the absolute position of the signal reception unit from the signal received by the signal reception unit;
A drive amount detector for detecting the drive amount of the actuator;
An absolute position calculation unit that calculates the absolute position of the movable unit from the position information calculated by the main body position calculation unit and the drive amount of the actuator detected by the drive amount detection unit,
Its absolute position calculator is
A timer for counting the time when the drive amount of the actuator is detected by the drive amount detector; and a storage unit for sequentially storing the drive amount of the actuator detected by the drive amount detector at a predetermined time interval together with the detection time counted by the timer; ,
Based on the transmission time information of the signal corresponding to the position information calculated by the main body position calculation unit, the drive amount that identifies the drive amount of the actuator at the time of signal transmission from the drive amounts stored in the storage unit A specific part,
A movable part position calculating unit that calculates the absolute position of the movable part at the time of transmitting a corresponding signal from the position information calculated by the main body position calculating part and the driving amount specified by the driving amount specifying part is provided. Mobile control system.   The movement according to claim 1, wherein the absolute position calculation unit further includes a correction unit that corrects a deviation between a time measured by the timer and time information included in a signal transmitted from the signal transmission device. Body control system.   The correction unit calculates the absolute position of the signal reception unit by the main body position calculation unit at predetermined time intervals while operating the main body in a preset operation pattern, and the operation performed by the main body and the main body position calculation unit. 3. The movement according to claim 2, wherein a deviation between the time measured by the timer and the time information included in the signal transmitted from the signal transmitting device is corrected from the calculated deviation from the absolute position orbit of the signal receiving unit. Body control system.   The absolute position calculation unit further includes a predicted position calculation unit that predicts the current absolute position of the movable unit based on the absolute position of the movable unit calculated by the movable unit position calculation unit. 4. The mobile control system according to any one of 3 above. A main body, a movable part coupled to the main body via a joint, an actuator that drives the joint, a signal receiving part that receives a signal, a drive amount detection part that detects the drive amount of the actuator, and a time count A moving body control system including a timer, a moving body that freely moves in a space including a storage unit that stores data, and a signal transmission device that transmits a signal including transmission time information to the signal receiving unit. In the method of calculating the absolute position of the movable part of the moving body,
Storing the drive amount of the actuator detected by the drive amount detection unit in the storage unit in order at a predetermined time interval together with the detection time;
Transmitting a signal including time information indicating a transmission time from the signal transmission device;
Receiving the signal by the signal receiving unit, and calculating the absolute position of the signal receiving unit from the received signal;
Identifying the driving amount of the actuator at the time when the signal is transmitted based on the transmission time information of the signal received by the signal receiving unit from among the driving amounts stored in the storage unit;
A calculation method comprising: calculating the absolute position of the movable part from the calculated absolute position of the signal receiving part and the specified driving amount.

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