Kristofer S.J. Pister (Advisor)

Research Advised by Professor Kristofer S.J. Pister

Algorithms for Distributed Sensor Networks

James D. McLurkin
Kristofer S. J. Pister

A distributed sensor network is many (100-10000) autonomous sensor nodes spread out over a large area. Each node is equipped with a processor, mission-specific sensors, and short-range communications. Local interactions between sensor nodes allow them to reach global conclusions from their data. This work develops algorithms that allow:

The group to establish robust spatial patterns of messages The group to develop a communications network by dividing tasks among themselves Each mote to determine its position in physical space based on their location in the network topology Each mote...

A System Supporting Tiny Networked Sensors

Jason Hill
David Culler
Kristofer Pister

As the post-PC era emerges, several new niches of computer system design are taking shape with characteristics that are quite different from traditional desktop and server regimes. One of the most interesting of these new design regimes is networked sensors. The networked sensor is enabled, in part, by "Moore's Law" pushing computing and storage into a smaller, cheaper, lower-power unit. However, three other trends are equally important: complete systems on a chip, integrated low-power communication, and integrated low-power devices that interact with the physical world. The combination of...

Adversarial Swarm Defense with Decentralized Swarms

Jason Zhou
Kristofer S.J. Pister

The rapid proliferation of unmanned aerial vehicles (UAVs) in both commercial and consumer applications in recent years raises serious concerns of public security, as the versatility of UAVs allow the platform to be easily adapted for malicious activities by adversarial actors. While interdiction methods exist, they are either indiscriminate or are unable to disable a large swarm of drones. Recent work in wireless communications, microelectromechanical systems, fabrication, and multi-agent reinforcement learning make UAV-based counter-UAV systems increasingly feasible - that is, defense...

Analyzing the Prediction Accuracy of Trajectory-Based Models with High-Dimensional Control Policies for Long-term Planning in MBRL

Howard Zhang
Kristofer S.J. Pister

Learning effective policies with model-based reinforcement learning is highly dependent on the accuracy of the dynamics model. Recently, a new parametrization called the trajectory-based model was introduced, which takes in an initial state, a future time index, and control policy parameters, and returns the state at that future time index [3]. This new method has demonstrated improved prediction accuracy in long horizons, increased sample efficiency, and ability to predict the task reward. However, this model has limited transferability to MBRL due to the limited expressivity of its...

Small Autonomous Robot Actuator (SARA): A Solar-powered Wireless MEMS Gripper

Alex Moreno
Kristofer S.J. Pister

Solar-powered actuation of a 15 mN electrostatic MEMS gripper was demonstrated while wirelessly triggered by IEEE 802.15.4 RF signals. The solar-powered gripper was shown to actuate at a rate of 640 um/s. The complete system is composed of three capacitors and three chips: MEMS gripper, microprocessor/crystal-free radio, and solar cell array/high voltage buffer. Control signals for the electrostatic inchworm motors originate from the 3x2x0.3 mm3 chip with an ARM Cortex-M0 microprocessor and are passed through 119V high voltage buffers. Power for all components, including the crystal-free...

Redesigning Power Systems on a Single Chip Micro Mote with Berkeley Analog Generator Low Dropout Series Regulator Generation

Jackson Paddock
Kristofer S.J. Pister

The Single Chip Micro Mote (SCμM) is a crystal-free radio chip with an on-board CPU developed at UC Berkeley in the Swarm Lab. This chip was designed to function as the brain of an untethered microrobot with no external components other than a power source required. SCμM also features an optical programmer so that no cables are even needed to program it. With its size and functionality, SCμM has the potential to allow a swarm of microrobots to communicate and perform complex tasks in tandem.

Like every other circuit, SCμM needs power to operate, and one of the most common power...

Jason Zhou

Electrical Engineering and Computer Sciences
Professor Kristofer S.J. Pister (Advisor)
M.S. 2021

Quadrotor-Based Lighthouse Localization with Time-Synchronized Wireless Sensor Nodes and Bearing-Only Measurements

Brian G. Kilberg
Felipe M. R. Campos
Craig Schindler
Kristofer S.J. Pister

Some robotic localization methods, such as ultra wideband localization and lighthouse localization, require external localization infrastructure in order to operate. However, there are situations where this localization infrastructure does not exist in the field, such as robotic exploration tasks. Deploying low power wireless sensor networks (WSNs) as localization infrastructure can potentially solve this problem. In this work, we demonstrate the use of an OpenWSN network of miniaturized low power sensor nodes as localization infrastructure. We demonstrate a quadrotor performing laser-...

QuickCal: Assisted Calibration for Crystal-Free Micro-Motes

Tengfei Chang
Thomas Watteyne
Filip Maksimovic
Brad Wheeler
David C. Burnett
Titan Yuan
Xavier Vilajosana
Kristofer S.J. Pister

The Single Chip Micro Mote (SCµM) is a crystal-free single-chip mote that brings us one step closer to the Smart Dust vision, in particular as it can communicate with off-the-shelf IEEE802.15.4 and Bluetooth Low Energy devices. However, before it can be part of such networks, the crystal-free SCµM chip needs to be able to accurately tune its communication frequency to synchronize to the network. This is a challenge since its on-board RC and LC-based resonating circuits have a drift rate that can be 3 orders of magnitude worse than crystal based oscillators typically used in today’s radios...

Stencil-Printed Lithium-Ion Micro Batteries for IoT Applications

Anju Toor
Albert Wen
Filip Maksimovic
Abhinav M. Gaikwad
Kristofer S.J. Pister
Ana C. Arias

A battery design and fabrication process is demonstrated to make Lithium-ion (Li-ion) microbatteries with high capacity to power IoT devices. The battery consists of printed anode and cathode layers based on graphite and lithium cobalt oxide (LCO) respectively. The active area of the electrodes is scaled down to 1 mm2 and the resulting electrochemical performance is evaluated. These miniature batteries demonstrate a significantly higher discharge capacity (6.4 mAh/cm2) and energy density (23.6 mWh/cm2) than thin-film and thick-film, and 3D microbatteries. This work shows a miniaturized Li-...