Closed chain linkages, that contain one or more
kinematic loops, admit a much greater variety than open
chains; thus, their analysis and synthesis are consequently
more complicated. Within this paper, we propose a general
algorithm for structural-parametric synthesis of linkages with
closed kinematic chains. The proposed method, previously used
for synthesis of anthropomorphic grippers’ fingers’ linkages and
galloping robots’ legs’ mechanisms, was applied to synthesize
the mechanics of an exosuit spine module to ensure ergonomics.
Wearable robots such as exosuits are used to reduce fatigue and
injuries, as well as increase the productivity of industry workers.
Exosuits’ design is challenging since human motion is not as
deterministic and precision as traditional robots’ motion. The
proposed method gives instructions for design steps and uses nongradient optimization techniques, such as genetic algorithms, for topology, parametric, and control co-design. In the considered example, an exosuit spine model has to not only compensate loads, but also does not interfere with the natural human motions.
We have used a dataset that contains participants’ whole-body
kinematics in order to check the ergonomics of an existing exosuit and improve its ergonomics using the proposed method.The
article contains general decryption of the proposed method, an
elaborated example with structural and parametric synthesis for
an exosuit design, and simulation results.