In this paper, an integrated ankle torque sensor and mechanism (Foot Link) of a Tendon driven-type wearing walking aid robot were designed. The foot link consists of an ankle torque sensor and a mechanism connected to the footrest. The size of the sensing part of the ankle torque sensor was designed through structural analysis and assembled by attaching a strain gauge. As a result, the reproducibility error and the nonlinearity error were within 0.04%, respectively. And the calibration result of the ankle torque sensor, reproducibility error, and non-linearity error were identified to be within 1%, respectively. Therefore, it is proposed that the ankle torque sensor presented in this paper can be used to measure the torque acting on the tendon-driven walking aid robot.

In this paper, we design and fabricate a wearable walking-assist robot using a tendon-driven method. Most wearable walking-assist robots are designed using the method of the attaching of the motors to the hip, knee, and ankle joints. The robot needs the capacities of the motors attached to the hip and knee joints to equal the weights of the motors attached to the knee and ankle joints and the motor attached to the ankle, respectively. To solve these problems, we design and fabricate the wearable walking-assist robot using a tendon-driven method that rotates the joints by attaching the motors of the hip, knee, and ankle joints to the waist joint, and pulling it with a line. The gait patterns of a normal person are photographed and analyzed, thereby providing the ankle position (x, y) during the walking that is then calculated using the forward kinematic equation, while each joint angle is calculated using the inverse kinematic equation. As a result of the characteristic experiment of the wearable walking-assist robot, the resultant walking aspect is similar to that of the normal person.