International audienceThis paper presents the design of an observer for a lightweight robotic arm actuated by a single biased Shape Memory Alloy (SMA) wire. The internal states of the system are estimated via an Extended Kalman Filter (EKF) with sliding modeunknown input and states estimation. This observer allows estimating the temperature, stress and martensite fraction rate of the SMA wire. This approach avoids the use of switching dynamics in the observer's model, due to the martensite fraction being considered as the unknown input. The discretized model of the robotic arm and observer development is presented. Finally the effectiveness of the proposed observer is tested in simulation
