Sensor Design And Motion Control For Soft Surgical Robot

Because of its material properties and structural characteristics,the cable driven soft robot have better flexibility,accessibility and environmental compliance than the rigid-body robot.Soft robot,designed for minimally invasive surgery,could get the target which can hardly be achieved by rigid manipulator or gurgeon.To further reduce the work of the surgeon and provide a more stable environment,a surgical system with automatically motion compensation for organ movement should be fabricated.First of all,environemtn information should be perceived.In this paper,the design of the proximity sensor and the force sensor for the cable driven soft robot have been proposed.Then we manufacture these sensor,as well as finish the calibration and performance test work of these self-fabricated sensor.The control experiment was carried out by using the soft operating arm with our sensors.According to the experiments,the practicability of the sensors are verified.This paper presents a optical-based proximity sensor.It is used to provide the information,when the image information is missing due to the influence of occlusion comes up to the camera lens.In addition,when the surgical instrument is too long and the interaction can not be fed back with the force sensor,it is also possible to use a proximity sensor for the target organ movement perception.In order to be used in the surgical environment,the sensor has been calibrated for different target surfaces and in different environment.The influence of media environments,external light have been tested.And the possible structure effect is considered,too.Finally,the position control experiment of the static target,which proves the usability of the system,is carried out by using the soft robot embedded with the proximity sensor.In this paper,the design of the optical fiber based silica gel force sensor have been proposed.This paper presents two kinds of force sensor design prototype,and compare these sensora according to their performance.Considering of the special using environment of the sensor,the surgical robot has high requirement for sturcture integration.Using the sensor's light transmittance property,we further proposes a fusion scheme of the proximity sensor and the force sensor.Then,we test and analyze the performance of the sensor based on the calibration experiment.Based on the sof manipulator platform embedded with the sensor,the force control experiment of the static object is carried out.And the practicability of the sensor is verified with this experiment.Moreover,we use this system to compare the impact absorption ability of the soft arm and the rigid arm,to verify the safety of soft surgical robot.At last,an adaptive iterative learning control algorithm is proposed for heart tracking task of the soft robot system.To prove the convergence of the algorithm,the Lyapunov function of the discrete-time system is proposed for the stability analysis of the controller.In order to evaluate the performance of the proposed controller,we use the PD position controller and the adaptive iterative learning controller to do the tracking experiment on the simulated heart platform.Then we compare and analyze the result of these two methods.