The use of industrial robots for machining operations such as polishing is gaining popularity these days. However, maintaining a constant normal contact on unknown geometrical surfaces still remains a challenge. In order to cope with the issue, this research has developed a unique compliant robotic end-effector that can measure the depth and angles deviation of the robot from the normal complex surfaces in real-time without any prior geometric model of the workpiece. The indigenously developed compliant robotic end-effector is made up of three main components: a novel 3-axis force/torque sensor, a compliant contact pin, and a data acquisition board (DAQ). Initially, the 3-axis force/torque sensor has been validated with both simulation and testing. The advantage of being able to take measurements in real-time is provided by the DAQ’s automatic weight compensation feature. Additionally, the pose correction algorithm receives the estimated contact force as feedback during robot surface tracking in order to assess depth and angles and determine the proper distance and perpendicular relationship between the surface and end-effector. The proposed scheme is then evaluated using a 6-axis industrial robot. The experimental results show that the maximum average depth and angle errors are 0.13 mm and 0.64°, respectively. The developed system has achieved significant improvement in contact-based robot surface measuring.

The use of robots for machining operations has become very popular in the last few decades. However, the challenge of the robotic-based machining process, such as surface finishing on curved surfaces, still persists. Prior studies (non-contact- and contact-based) have their own limitations, such as fixture error and surface friction. To cope with these challenges, this study proposes an advanced technique for path correction and normal trajectory generation while tracking a curved workpiece’s surface. Initially, a key-point selection approach is used to estimate a reference workpiece’s coordinates using a depth measuring tool. This approach overcomes the fixture errors and enables the robot to track the desired path, i.e., where the surface normal trajectory is needed. Subsequently, this study employs an attached RGB-D camera on the end-effector of the robot for determining the depth and angle between the robot and the contact surface, which nullifies surface friction issues. The point cloud information of the contact surface is employed by the pose correction algorithm to guarantee the robot’s perpendicularity and constant contact with the surface. The efficiency of the proposed technique is analyzed by carrying out several experimental trials using a 6 DOF robot manipulator. The results reveal a better normal trajectory generation than previous state-of-the-art research, with an average angle and depth error of 1.8 degrees and 0.4 mm.

The edge sharpness of a propeller blade plays a vital role in improving energy transmission efficiency and reducing the power required to propel the vehicle. However, producing finely sharpened edges through casting is challenging due to the risk of breakage. Additionally, the blade profile of the wax model can deform during drying, making it difficult to achieve the required edge thickness. To automate the sharpening process, we propose an intelligent system consisting of a six-DoF industrial robot and a laser-vision sensor. The system improves machining accuracy through an iterative grinding compensation strategy that eliminates material residuals based on profile data from the vision sensor. An indigenously designed compliance mechanism is employed to enhance the performance of robotic grinding which is actively controlled by an electronic proportional pressure regulator to adjust the contact force and position between the workpiece and abrasive belt. The system’s reliability and functionality are validated using three different workpiece models of four-blade propellers, achieving accurate and efficient machining within the required thickness tolerances. The proposed system provides a promising solution for finely sharpened propeller blade edges, addressing challenges associated with the earlier robotic-based grinding studies.

The raw salt should be reduced the size to convert it into consumption salt. Salt crushing machine generally was designed to reduce salt grain size using rollers for crushing. The small-capacity salt-crushing machine should be designed to meet the needs of small businesses. This study aims to design a salt-crushing machine in a small capacity with a proper power transmission system that will be applied to a roller-type salt crusher. The transmission system is designed to upgrade the performance of roller-type salt crushers through V-belt and pulley transmission mechanisms and obtain the appropriate size or type of V-belt and pulley based on the capacity of the drive motor. The results show power required to crush salt by this system is 299.46 W. The motor used is a single-phase AC motor that has a power size of 1/2 HP, and the corresponding v belt is type A with a size of 51 inches, the rpm needed is 360 rpm, and the distance between rollers is 0,7 mm. Then the pulley needed is with a ratio of 1: 4. The pulleys used are type A1 which has a diameter of 3 inches and 12 inches. The average salt weight loss after the crushing process was 14.27%.