A two-degree-of-freedom（DOF）cable-driven based robot for detecting boiler pipes is designed and fabricated.Point-to-point straight line trajectory movement is achieved.Shrinkage testbed and its control system are designed and established.Dynamic model for the cable-driven robot is established

and foreard and inverse solution laws of position

velocity and acceleration are studied.A straight linear trajectory planning approach is developed

which is based on the position discrete differential and trapezoidal speed planning.Path planning trajectory is presented

then simulating and analyzing the laws of the length and velocity of the driving cable based on the point-to-point linear trajectory planning algorithm.The research shows that in point to point straight line trajectory movement

cable length change continuously

it assure that cable-driven robot can run smoothly

continuously

and positioning precision can meet requirement of detection.