Jointsallow

Jointsallow is a concept in biomechanics and robotics referring to the defined allowable motion and tolerance of a joint within a system. It encompasses angular range, linear play, backlash, and deformation under load, and is used to ensure stability and safety in multi-joint mechanisms. The term emerged in early 21st-century engineering literature as systems grew more complex and required explicit joint safety envelopes. In practice, jointsallow is described by a safety envelope or "allowable motion set" consisting of upper and lower bounds on angular displacement, translational clearance, and torque limits. It may be specified as ISO-like tolerances or as a functional constraint within control software. In mechanical design, defining jointsallow early helps prevent overextension, collision, and excessive wear by constraining actuators to operate within this envelope. In robotics and prosthetics, jointsallow informs trajectory planning, impedance control, and fault detection by providing a model of permissible joint behavior under varying loads. Measurement involves tests for range of motion, backlash, stiffness, and torque saturation, often combined into a compact criterion such as a safety margin or envelope function. Limitations include variability across materials, wear over time, and changes in temperature or lubrication; inaccurate models can lead to overly conservative or unsafe operation. See also joint clearance, range of motion, and safe operating envelope. Jointsallow represents a design and analysis tool rather than a physical object, used to ensure predictable and safe joint performance.