Research On Cable Installation Method In Constrained Space

Cable assembly are a common task in industrial production.Cable is manually operated by assemblers beacause it is deformed under external force and the deformation of the cable is unpredictable.However,as the cost of employing people rises,the production cost of products continues to rise.How to control costs has become the primary goal of enterprises.The use of robots for assembly work has become a trend,however,the robot cannot get the deformation information of the cable in real time,it is easy to encounter obstacles during the assembly process,which cause the failure of theb assembly.In response to this problem,this paper studies cable shape control technology and automated assembly technology.Measurement of the deformation state of the cable is important for assembly tasks.When measuring the deformation state of the marked cable,the deformation of the cable is measured by locating the marked points attached to the surface of the cable.Cable segmentation was performed using color information.Morphological processing was performed to reduce noise and make the markers clearer.Finally,the outline of the markers on the cable is extracted,and the pose information of the cable is calculated.When measuring the deformation state of the unmarked cable,the center line of the cable is extracted,and the deformation of the cable is measured by positioning the center line.The deformable object is model-identified before the shape control,which not only requires a large number of deformation parameters,but time-consuming.To solve this problem,this paper uses the model-free deformable object control theory to control the shape of the deformable object.The design of the vision-based shape controller was carried out according to the method proposed by Dmitry Berenson.In the shape control system,the shape feature error is expressed as the error between the theoretical deformation feature and the current deformation feature.Combined with the deformation Jacobian matrix and robot Jacobian matrix,the motion control amount of the robot motion space is obtained,and the shape control of the deformable object is completed.In order to achieve the assembly of the cable and avoid contact with surrounding obstacles at the same time.Combining shape control with obstacle avoidance control based on artificial potential field,a method of cable automatic assembly in constrained space is proposed.In order to verify the effectiveness of the proposed method,this paper builds a visual servo experimental platform,which includes vision system and robot control system.Before the experiment,the kinect v2 camera used in the vision system was calibrated and the calibration results were obtained.Subsequently,the Eye-to-hand hand-eye system was calibrated to obtain a hand-eye relationship matrix.Finally,the automated assembly experiments of marked cable and unmarked cable under constrained space are carried out respectively.The experimental results are analyzed in detail.The experimental results verify the effectiveness of the controller based on artificial potential field method.