### Abstract

The purpose of this study is to present a general mathematical framework to compute a set of feedback matrices which stabilize an unstable nonlinear anthropomorphic musculoskeletal dynamic model. This method is activity specific and involves four fundamental stages. First, from muscle activation data (input) and motion degrees-of-freedoin (output) a dynamic experimental model is obtained using system identification schemes. Second, a nonlinear musculoskeletal dynamic model which contains the same number of muscles and degrees-of-freedom and best represents the activity being considered is proposed. Third, the nonlinear musculoskeletal model (anthropomorphic model) is replaced by a family of linear systems, parameterized by the same set of input/ output data (nominal points) used in the identification of the experimental model. Finally, a set of stabilizing output feedback matrices, parameterized again by the same set of nominal points, is computed such that when combined with the anthropomorphic model, the combined system resembles the structural form of the experimental model. The method is illustrated in regard to the human squat activity.

Original language | English (US) |
---|---|

Pages (from-to) | 165-187 |

Number of pages | 23 |

Journal | Computer Methods in Biomechanics and Biomedical Engineering |

Volume | 4 |

Issue number | 2 |

DOIs | |

State | Published - Dec 1 2001 |

Externally published | Yes |

### Fingerprint

### Keywords

- Anthropomorphic model
- Experimental model
- Extended linearization
- Gain scheduling
- Generalized inverse
- Nominal points
- System identification
- System Jacobians

### ASJC Scopus subject areas

- Bioengineering
- Biomedical Engineering
- Human-Computer Interaction
- Computer Science Applications

### Cite this

**Computation of a stabilizing set of feedback matrices of a large-scale nonlinear musculoskeletal dynamic model.** / Dhaher, Yasin Y.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - Computation of a stabilizing set of feedback matrices of a large-scale nonlinear musculoskeletal dynamic model

AU - Dhaher, Yasin Y.

PY - 2001/12/1

Y1 - 2001/12/1

N2 - The purpose of this study is to present a general mathematical framework to compute a set of feedback matrices which stabilize an unstable nonlinear anthropomorphic musculoskeletal dynamic model. This method is activity specific and involves four fundamental stages. First, from muscle activation data (input) and motion degrees-of-freedoin (output) a dynamic experimental model is obtained using system identification schemes. Second, a nonlinear musculoskeletal dynamic model which contains the same number of muscles and degrees-of-freedom and best represents the activity being considered is proposed. Third, the nonlinear musculoskeletal model (anthropomorphic model) is replaced by a family of linear systems, parameterized by the same set of input/ output data (nominal points) used in the identification of the experimental model. Finally, a set of stabilizing output feedback matrices, parameterized again by the same set of nominal points, is computed such that when combined with the anthropomorphic model, the combined system resembles the structural form of the experimental model. The method is illustrated in regard to the human squat activity.

AB - The purpose of this study is to present a general mathematical framework to compute a set of feedback matrices which stabilize an unstable nonlinear anthropomorphic musculoskeletal dynamic model. This method is activity specific and involves four fundamental stages. First, from muscle activation data (input) and motion degrees-of-freedoin (output) a dynamic experimental model is obtained using system identification schemes. Second, a nonlinear musculoskeletal dynamic model which contains the same number of muscles and degrees-of-freedom and best represents the activity being considered is proposed. Third, the nonlinear musculoskeletal model (anthropomorphic model) is replaced by a family of linear systems, parameterized by the same set of input/ output data (nominal points) used in the identification of the experimental model. Finally, a set of stabilizing output feedback matrices, parameterized again by the same set of nominal points, is computed such that when combined with the anthropomorphic model, the combined system resembles the structural form of the experimental model. The method is illustrated in regard to the human squat activity.

KW - Anthropomorphic model

KW - Experimental model

KW - Extended linearization

KW - Gain scheduling

KW - Generalized inverse

KW - Nominal points

KW - System identification

KW - System Jacobians

UR - http://www.scopus.com/inward/record.url?scp=0035259745&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035259745&partnerID=8YFLogxK

U2 - 10.1080/10255840008908003

DO - 10.1080/10255840008908003

M3 - Article

C2 - 11264866

AN - SCOPUS:0035259745

VL - 4

SP - 165

EP - 187

JO - Computer Methods in Biomechanics and Biomedical Engineering

JF - Computer Methods in Biomechanics and Biomedical Engineering

SN - 1025-5842

IS - 2

ER -