Fig. 14

Measurement of traction forces with both prototypes. a, b The experimental setup and measured results, respectively. The load values and speeds are obtained by \(100\left( {1 + N \cdot m_{\text{N}} /m_{\text{p}} } \right) [\% ]\) and \(100(v/v_{0} ) [\% ]\), respectively, where \(m_{\text{p}}\) and \(m_{\text{N}}\) denote the weight of the prototype and M8 nut, respectively, \(N\) is the number of nuts, and \(v\) and \(v_{0}\) denote the climbing speed with nuts and without nut