Kristofer S.J. Pister (Advisor)

Research Advised by Professor Kristofer S.J. Pister

Pister Group:  List of Projects | List of Researchers

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
2021

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
2021

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
2021

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

Alumni
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
2020

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
2020

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
2020

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-...

Actuation and Localization of Resource-Constrained Autonomous Microrobotic Systems

Brian Kilberg
2021

With recent advances in miniaturized wireless system-on-chips, microactuators, sensors, and power supplies, autonomous microrobotic systems that can independently explore spaces and process information are approaching fruition. These systems, which can be smaller than1 cubic centimeter, require actuation and localization modalities that are compatible with these strict payload and size requirements. The first part of this dissertation focuses on the development of millimeter-scale aerodynamic control surfaces actuated by electrostatic inchworm motors, intended for controlling pencil-size...

BLISS: Berkeley Low-Cost Interplanetary Solar Sail

Alexander Alvara
2021
Spring 2021 BSAC Research Review Presentation View Slides View Presentation

Monolithic Wireless Transceiver Design

Filip Maksimovic
Kristofer S.J. Pister
2020

Recently, there has been an increasing push to make everything wireless. In contrast to high-performance cellular communication, where the demand for enormous quantities of data is skyrocketing, these small wireless sensor and actuator nodes require low power, low cost, and a high degree of system integration. A typical CMOS system-on-chip requires a number of off-chip components for proper operation, namely, a crystal oscillator to act as an accurate frequency reference, and an antenna. The primary goal of this thesis is to address the hurdles associated with operating without these...