Design and prototyping of a smart powered lifting robotic arm (SPLRA)

Engineering notes

Key topics: autonomous driving, control. See the paper for implementation details and experimental results.

Chinese explanation / 中文解读

中文解读待补充：本站会优先为端到端自动驾驶、BEV感知、3D目标检测、轨迹预测、路径规划、LiDAR感知等高价值论文补充中文说明。

Original abstract

This paper presents the design, prototype fabrication, and experimentally validated testing of the Smart Powered Lifting Robotic Arm (SPLRA) for low-cost applications in areas of education, prototyping, and lab automation. It aims to tackle common shortcomings found in many affordable robotic arms in which mechanical design, actuator sizing, structural verification, gear transmission, embedded control system design, and payload test analysis are typically considered separately without adequate empirical validation. SPLRA uses SolidWorks CAD for its link and gear designs, FDM printed PLA/PETG components, NEMA 17 stepper motors, spur gear transmission, Arduino open-loop control, and human-machine Bluetooth interface through an HC-06 module. The actuator sizing problem has been reformulated based on electrical motor torque requirements and not the force used by hydraulic or pneumatic actuators. The sizing of the lifting joint involved factors such as payload force, perpendicular distance to the pivot point, dynamic load factor, gear ratio, transmission efficiency, and factor of safety. In a lifting of a payload of 0.8 kg with a moment arm distance of 0.2 m, static torque equaled 1.57 Nm, service torque equalled 2.04 Nm, while geared output torque equals approximately 6.0 Nm giving an actuator safety factor of 2.94. The adequacy of the structure was verified analytically by performing the stress analysis with respect to the maximum material strength of PLA/PETG and design factor of safety of 2.0. The critical component in this structure was the EBAarm2_006_horarm, which had a calculated equivalent stress of 18.6 MPa and a safety factor of 2.69 less than the allowable design stress. The experimental validation involved multiple lift-and-place tests with the specified 0.8 kg payload. The SPLRA lifted the 0.8 kg payload 100% successfully in 10 cycles. Its repeatability in terms of position was 2.47 ± 0.58 mm and 0.41 ± 0.23° in angle. It did not exhibit any payload falling off, motor stalling, visible plastic deformations, loose joints, mounting hole stretching, nor layer de-lamination. Lift time varied from 4.0 s at 90 degrees to 2.6 s at 180 degrees suggesting greater mechanical advantage at high angles of lifting. Electrical test results showed stable running within the 24 W power supply capability.

Links and sources

• PDF from original source

Comments