### Abstract

In this study, we deal with the twisting motion of a falling cat robot by means of two torque inputs around her waist. The cat robot consists of two rigid columns and has two internal actuators at the joint to generate torque inputs around normal coordinates. This system is a nonholonomic system whose angular momentum is conserved. We formulate the state equation that has torque inputs to the joint by using the nonholonomic constraint and the Lagrange-d'Alembert principle. Then, we transform the system into a linear parameter varying system. In order to improve error learning of a final-state control method, we provide the initial inputs in order to determine the appropriate rotation direction in the early stage of the twisting motion. Next, we introduce the method of the artificial potential function to the final-state control in order to make the maximum bending angle small. The feedforward torque inputs can be obtained by the final-state control in order to bring the system from the initial state to the final state in the desired time. In simulations, we also demonstrate that the two-link cat robot can land on her feet by using the 2-d.o.f. control system even when her waist damping coefficient varies.

Original language | English |
---|---|

Pages (from-to) | 325-343 |

Number of pages | 19 |

Journal | Advanced Robotics |

Volume | 16 |

Issue number | 4 |

DOIs | |

Publication status | Published - 2002 |

Externally published | Yes |

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### Keywords

- Error learning
- Final-state control
- Motion control
- Nonholonomic constraint
- Two-link cat robot

### ASJC Scopus subject areas

- Control and Systems Engineering

### Cite this

*Advanced Robotics*,

*16*(4), 325-343. https://doi.org/10.1163/15685530260174511

**Final-state control of a two-link cat robot.** / Weng, Zhiqiang; Nishimura, Hidekazu.

Research output: Contribution to journal › Article

*Advanced Robotics*, vol. 16, no. 4, pp. 325-343. https://doi.org/10.1163/15685530260174511

}

TY - JOUR

T1 - Final-state control of a two-link cat robot

AU - Weng, Zhiqiang

AU - Nishimura, Hidekazu

PY - 2002

Y1 - 2002

N2 - In this study, we deal with the twisting motion of a falling cat robot by means of two torque inputs around her waist. The cat robot consists of two rigid columns and has two internal actuators at the joint to generate torque inputs around normal coordinates. This system is a nonholonomic system whose angular momentum is conserved. We formulate the state equation that has torque inputs to the joint by using the nonholonomic constraint and the Lagrange-d'Alembert principle. Then, we transform the system into a linear parameter varying system. In order to improve error learning of a final-state control method, we provide the initial inputs in order to determine the appropriate rotation direction in the early stage of the twisting motion. Next, we introduce the method of the artificial potential function to the final-state control in order to make the maximum bending angle small. The feedforward torque inputs can be obtained by the final-state control in order to bring the system from the initial state to the final state in the desired time. In simulations, we also demonstrate that the two-link cat robot can land on her feet by using the 2-d.o.f. control system even when her waist damping coefficient varies.

AB - In this study, we deal with the twisting motion of a falling cat robot by means of two torque inputs around her waist. The cat robot consists of two rigid columns and has two internal actuators at the joint to generate torque inputs around normal coordinates. This system is a nonholonomic system whose angular momentum is conserved. We formulate the state equation that has torque inputs to the joint by using the nonholonomic constraint and the Lagrange-d'Alembert principle. Then, we transform the system into a linear parameter varying system. In order to improve error learning of a final-state control method, we provide the initial inputs in order to determine the appropriate rotation direction in the early stage of the twisting motion. Next, we introduce the method of the artificial potential function to the final-state control in order to make the maximum bending angle small. The feedforward torque inputs can be obtained by the final-state control in order to bring the system from the initial state to the final state in the desired time. In simulations, we also demonstrate that the two-link cat robot can land on her feet by using the 2-d.o.f. control system even when her waist damping coefficient varies.

KW - Error learning

KW - Final-state control

KW - Motion control

KW - Nonholonomic constraint

KW - Two-link cat robot

UR - http://www.scopus.com/inward/record.url?scp=0036280519&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036280519&partnerID=8YFLogxK

U2 - 10.1163/15685530260174511

DO - 10.1163/15685530260174511

M3 - Article

AN - SCOPUS:0036280519

VL - 16

SP - 325

EP - 343

JO - Advanced Robotics

JF - Advanced Robotics

SN - 0169-1864

IS - 4

ER -