RSSI-Based Localization Technique for Robotic Arm Positioning

Localization is a critical aspect in the operation of a robotic arm, which enables precise and accurate movements within its environment. Transmitters and receivers are crucial components in the localization systems used to guide a robotic arm’s end-effector to follow a specific point. This information is essential for tasks that require high precision, such as assembling components, performing delicate surgeries, or handling fragile objects. Accurate localization improves the efficiency and safety of robotic operations, reducing errors, and improving the overall performance of automated systems. In this paper, a Receiver Signal Strength Indicator (RSSI) based localization method is applied using the estimated distances between anchor nodes around a robotic arm and a receiver to find the x, y, and z coordinates of the receiver with respect to the base of the robotic arm. Using inverse kinematics, we can use the coordinates to precisely move the end effector to the receiver location, as discussed in the conducted experimental evaluation. The experimental results reveal significant variations in RSSI measurements across the BLE, Wi-Fi, and LoRa wireless protocols, especially in short ranges below 20 cm. Among these, LoRa exhibited the highest stability in RSSI readings, which can be attributed to its sub-GHz operating frequency (868 MHz), which is less susceptible to rapid fading and multipath effects in indoor environments. Consequently, LoRa achieved superior localization accuracy compared to BLE and Wi-Fi.