Integration of the control electronics for a mm³-sized autonomous microrobot into a single chip

Abstract

Microrobots were proposed more than 20 years ago but it has proven challenging to integrate a power system and actuators into some few mm 3 . There have been some attempts to create an autonomous mobile microrobot but any has been successful. Moreover, the proposed microrobots were simply mobile platforms incapable of sensing its environment and taking decisions. I-SWARM has been designed to be a real autonomous microrobot. It is powered by solar cells and provided with a locomotion unit for moving, an IR module for communicating and a contact tip for detecting near objects. Those modules are managed by an ASIC designed specifically for I-SWARM. All the electronics (power electronics, buffers, ADCs, DACs, control unit, analog transducers and an oscillator) have been embedded in the ASIC due to the limited area, 3 x 3 mm 2 . The ASIC is a complete System On Chip (SoC) that has several features not reported before in any circuit for microrobots: communicate and act cooperatively with other I-SWARM microrobots, detect near objects, measure distance to an object, light trailing and reprogramability. This paper gives some guidelines to design integrated circuits for microrobots. A Fig. 1. Block diagram of the major electronics circuits for a microrobot.

A new binary arithmetic for finite-word-length linear controllers: MEMS applications

“…These two linear controllers were used in previous work [18] to control the FT-G100 microgripper (www.femtools.com) on a dSPACE platform. Source : [4] III. APPLICATION CONTEXT Microrobotics is one of the MEMS applications.…”

“…It is the field of miniature robotics, in particular mobile robots with characteristic dimensions less than 1mm. Microrobots [4] and Micromanipulators [19] are two outstanding examples of MEMS devices, dedicated to work in the micro-world. At this scale, the systems should have accuracy and resolution that are better than one micron.…”

“…This dictates the use of power-efficient solutions in control and in the implementation of the controller as well. A typical example is the mm 3 robots [4], called I-SWARM. It is a real autonomous mobile micro-robot; powered by solar cells, equipped with a locomotion unit for moving, an infra-red unit for communication, and a contact tip for detecting near objects.…”

“…One intermediate step toward portability will be to substitute the calculation unit used for the real-time calculation by an FPGA board, wherein only the control algorithm is embedded [3]. The ideal solution would be to incorporate the whole electronics (control, power, signal conditioning, and conversion) into a low-power ASIC [4], directly connected to the micro-gripper (Fig. 1).…”

Design of high-speed and low-power finite-word-length PID controllers

“…Therefore, the most appropriate PID in this case is PIDX_1 as it is the least power consumer. Adversely, for very fast dynamic systems, such as MEMS [45] or microrobotics applications [46], PIDX_n/2 is the most adequate option as it leads to the highest control rate.…”