Omnidirectional vehicle and method of controlling the same
First Claim
1. An omnidirectional vehicle comprising:
- a body;
at least one driving unit fixed to the body and including a steering shaft, a first actuator fixed to the body for driving the steering shaft, a driving wheel having a shaft, and a second actuator fixed to the body for driving the shaft of the driving wheel;
a bearing fixed to the body for axially supporting the steering shaft;
first power transmitting means for transmitting a power from the first actuator to the steering shaft to drive the steering shaft;
second power transmitting means for transmitting a power from the second actuator to the driving wheel to thereby drive the driving wheel; and
supporting means having a bearing and positioned below the steering shaft for axially supporting the driving wheel via the bearing to thereby rotate the driving wheel together with the steering shaft around a vertical axis of the body;
wherein said driving wheel is positioned in a first plane including the shaft of the driving wheel which is perpendicular to a second plane including a rotation axis of the steering shaft, said driving wheel located in the first plane being spaced apart for a first predetermined distance (d) from the second plane, said first plane being spaced apart for a second predetermined distance (s) from the rotation axis of the steering shaft at a point intersecting the second plane to thereby freely rotate the driving wheel around a horizontal axis, and said shaft of the driving wheel and the steering shaft do not cross each other.
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Accused Products
Abstract
An omnidirectional vehicle includes a body, and a plurality of units, each unit including a bearing rotatably supporting a steering shaft around a vertical axis with a rotor plate, and a driving wheel axially supported by a supporter fixed to the rotor plate. The driving wheel is positioned at a location spaced apart for a first offset distance from the steering shaft in the rolling direction of the driving wheel and spaced apart for a second offset distance from the steering shaft in the direction perpendicular to the rolling direction of the driving wheel. A first motor is fixed to the body for driving the steering shaft, and a second motor is fixed to the body for rotating the driving wheel. In the holonomic omnidirectional vehicle, the control system and the driving system are simplified, and interference therebetween is prevented. Also, it is possible to reduce the capacities of the actuators, the electric power for driving the vehicle and the manufacturing costs.
141 Citations
13 Claims
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1. An omnidirectional vehicle comprising:
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a body;
at least one driving unit fixed to the body and including a steering shaft, a first actuator fixed to the body for driving the steering shaft, a driving wheel having a shaft, and a second actuator fixed to the body for driving the shaft of the driving wheel;
a bearing fixed to the body for axially supporting the steering shaft;
first power transmitting means for transmitting a power from the first actuator to the steering shaft to drive the steering shaft;
second power transmitting means for transmitting a power from the second actuator to the driving wheel to thereby drive the driving wheel; and
supporting means having a bearing and positioned below the steering shaft for axially supporting the driving wheel via the bearing to thereby rotate the driving wheel together with the steering shaft around a vertical axis of the body;
wherein said driving wheel is positioned in a first plane including the shaft of the driving wheel which is perpendicular to a second plane including a rotation axis of the steering shaft, said driving wheel located in the first plane being spaced apart for a first predetermined distance (d) from the second plane, said first plane being spaced apart for a second predetermined distance (s) from the rotation axis of the steering shaft at a point intersecting the second plane to thereby freely rotate the driving wheel around a horizontal axis, and said shaft of the driving wheel and the steering shaft do not cross each other. - View Dependent Claims (2, 3, 4, 5, 6)
defining vehicle-based-coordinates, an origin thereof being set at a reference point of the vehicle; and
controlling an angular rotating velocity of said first actuator in each of the driving units and an angular rotating velocity of the second actuator in each of the driving units based on a following equation relating to position data of the steering shaft on each of the driving units on the vehicle-based-coordinates and orientation data of the driving units on the vehicle-based-coordinates;
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7. An omnidirectional vehicle comprising:
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a body having a vertical axis;
a driving set mounted on the body and including a plurality of driving units, each having a steering shaft and a driving wheel having a shaft;
first power transmitting means including one of a belt and a chain;
second power transmitting means;
a first actuator for driving the steering shafts of the driving units collectively via the first power transmitting means;
a second actuator for driving the driving wheels of the driving units via the second power transmitting means;
a bearing mounted on the driving set for rotatably supporting the body around the vertical axis;
a third actuator mounted on the driving set for rotating the body around the vertical axis;
third power transmitting means mounted on the driving set for transmitting power from the third actuator; and
supporting means positioned below the steering shafts for axially supporting the driving wheels via bearings;
wherein each of said driving wheel is positioned in a first plane including the shaft of the driving wheel which is perpendicular to a second plane including a rotation axis of the steering shaft, said driving wheel located in the first plane being spaced apart for a first predetermined distance (d) from the second plane, said first plane being spaced apart for a second predetermined distance (s) from the rotation axis of the steering shaft at a point intersecting the second plane to thereby freely rotate the driving wheel around a horizontal axis, and said shaft of the driving wheel and the steering shaft do not cross each other. - View Dependent Claims (8, 9, 10, 11, 12, 13)
controlling an angular rotating velocity of the first actuator, an angular rotating velocity of the second actuator, and an angular rotating velocity of the third actuator based on following equations to control directions and velocities of the translational movements of the driving units and the body, and an orientation of the body;
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10. The method according to claim 8, wherein said θ
- w is measured by angle measuring means comprising an angle detector fixed to the body of the vehicle and a shaft, said shaft of the angle detector being rotated by the first power transmitting means of the first actuator for driving the steering shafts.
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11. The method according to claim 9, wherein said angle measuring means comprises:
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a first integrating encoder for detecting a rotation of a shaft of the first actuator;
a second integrating encoder for detecting a rotation of a shaft of the third actuator;
an absolute encoder for detecting an orientation of the driving wheel with respect to the body; and
a differential counter for counting a number of pulses contained in a first pulse train from said first integrating encoder and a number of pulses contained in a second pulse train from the second integrating encoder;
wherein said first pulse train indicates a normal rotation or a reverse rotation of the first actuator, and is inputted to a positive input of the differential counter;
said second pulse train indicates a normal rotation or a reverse rotation of the second actuator, and is inputted to a negative input of the differential counter;
said differential counter subtracts the number of pulses contained in the second pulse train from the number of pulses contained in the first pulse train, and outputs a result of the subtraction; and
said angle measuring means uses an output of the differential counter for lower place bits and an output of the absolute encoder for upper place bits, and connects said lower place bits and said upper place bits to obtain a relative angle value between the orientation of the vehicle and the driving wheel.
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12. The method according to claim 9, further comprising:
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detecting a slip between the driving wheels and a ground based on an output of a sensor disposed on the driving set, said sensor detecting a rotation around the vertical axis of the vehicle, and having a gyroscope; and
correcting a measured relative angle value between the orientations of the driving wheels and the body of the vehicle based on a detected slip value.
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13. The method according to claim 9, further comprising:
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detecting a rotation angle around the vertical axis of the vehicle by a sensor disposed on the body of the vehicle having a gyroscope; and
adding a detected rotation angle to data of the orientation of the body of the vehicle to correct stored data of the orientation of the body of the vehicle.
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Specification