Kristofer S. J. Pister

Kristofer S. J. Pister
University of California, Berkeley | UCB · Department of Electrical Engineering and Computer Sciences

About

333
Publications
109,468
Reads
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23,418
Citations
Additional affiliations
January 1997 - present
University of California, Berkeley
Position
  • Professor
August 1992 - December 1996
University of California, Los Angeles
Education
August 1986 - December 1992
University of California, Berkeley
Field of study
  • Electrical Engineering and Computer Sciences
September 1982 - June 1986
University of California, San Diego
Field of study
  • Applied Physics

Publications

Publications (333)
Preprint
Full-text available
Accurately predicting the consequences of agents' actions is a key prerequisite for planning in robotic control. Model-based reinforcement learning (MBRL) is one paradigm which relies on the iterative learning and prediction of state-action transitions to solve a task. Deep MBRL has become a popular candidate, using a neural network to learn a dyna...
Article
We present a nonlinear dynamics model for lateral electrostatic gap closing actuators (GCAs) operated in air and underwater. We factor in finger bending and the release phase's initial velocity over prior work, and we systematically study the effect on GCA pull-in and release time by varying both the finger length and the release spring constant. S...
Article
Nonholonomic control is a candidate to control nonlinear systems with path-dependant states. We investigate an underactuated flying micro-aerial-vehicle, the ionocraft, that requires nonholonomic control in the yaw-direction for complete attitude control. Deploying an analytical control law involves substantial engineering design and is sensitive t...
Preprint
Full-text available
Accurately predicting the dynamics of robotic systems is crucial for model-based control and reinforcement learning. The most common way to estimate dynamics is by fitting a one-step ahead prediction model and using it to recursively propagate the predicted state distribution over long horizons. Unfortunately, this approach is known to compound eve...
Article
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 electrochemi...
Article
We present a system for centimeter-precision 3 dimensional localization of a 2 x 3 x 0.3 mm³,, 5 mg, wireless system-on-chip by utilizing a temporally-structured infrared illumination scheme generated by a set of base stations. This 3D localization system builds on previous work by adding a second lighthouse station to enable 3D localization and us...
Article
Full-text available
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)...
Preprint
Building intelligent autonomous systems at any scale is challenging. The sensing and computation constraints of a microrobot platform make the problems harder. We present improvements to learning-based methods for on-board learning of locomotion, classification, and navigation of microrobots. We show how simulated locomotion can be achieved with mo...
Article
Full-text available
The single chip integration of a wireless sensor node would allow for cheap, low-power, dust-size devices. The key to realizing this vision is to eliminate bulky off-chip frequency references such as crystal oscillators or resonators, and their associated power-hungry circuitry. The immediate challenge of removing off-chip references is that there...
Article
Full-text available
Designing effective low-level robot controllers often entail platform-specific implementations that require manual heuristic parameter tuning, significant system knowledge, or long design times. With the rising number of robotic and mechatronic systems deployed across areas ranging from industrial automation to intelligent toys, the need for a gene...
Article
The convergence of operational and information technologies in the industry requires a new generation of IP-compliant communication protocols that can meet the industrial performance requirements while facilitating the integration with novel web-based supervisory control and data acquisition (SCADA) systems. For more than a decade, the industry has...
Preprint
Robot design is often a slow and difficult process requiring the iterative construction and testing of prototypes, with the goal of sequentially optimizing the design. For most robots, this process is further complicated by the need, when validating the capabilities of the hardware to solve the desired task, to already have an appropriate controlle...
Preprint
The elimination of the off-chip frequency reference, typically a crystal oscillator, would bring important benefits in terms of size, price and energy efficiency to IEEE802.15.4 compliant radios and systems-on-chip. The stability of on-chip oscillators is orders of magnitude worse than that of a crystal. It is known that as the temperature changes,...
Article
Microwire and microelectrode arrays used for cortical neural recording typically consist of tens to hundreds of recording sites, but often only a fraction of these sites are in close enough proximity to firing neurons to record singleunit activity. Recent work has demonstrated precise, depthcontrollable mechanisms for the insertion of single neural...
Preprint
Full-text available
Generating low-level robot controllers often requires manual parameters tuning and significant system knowledge, which can result in long design times for highly specialized controllers. With the growth of automation, the need for such controllers might grow faster than the number of expert designers. To address the problem of rapidly generating lo...
Article
Ideal microrobots are on the millimeter-scale with integrated actuators, power sources, sensors, and controllers. Numerous researchers are inspired by insects for the mechanical or electrical design of microrobots. Previously, the authors proposed and demonstrated microrobots that can replicate the tripod gait locomotion of an ant, the legs of whic...
Article
Objective: Microwire and Utah-style neural recording arrays are the predominant devices used for cortical neural recording, but the implanted electrodes cause a significant adverse biological response and suffer from well-studied performance degradation. Recent work has demonstrated that carbon fiber electrodes do not elicit this same adverse resp...
Article
The Internet-of-Things (IoT) promises one trillion wireless sensors in the next 10 to 15 years. To enable this scale, we present the experimental results on the time-keeping ability of crystal-free radios to lower the cost of the wireless sensors. We propose a Network Referenced Frequency Lock Loop and demonstrate a one sigma mean frequency accurac...
Preprint
Robots and control systems rely upon precise timing of sensors and actuators in order to operate intelligently. We present a functioning hexapod robot that walks with a dual tripod gait; each tripod is actuated using its own local controller running on a separate wireless node. We compare and report the results of operating the robot using two diff...
Preprint
Full-text available
Microwire and microelectrode arrays used for cortical neural recording typically consist of tens to hundreds of recording sites, but often only a fraction of these sites is in close enough proximity to firing neurons to record single-unit activity. Recent work has demonstrated precise, depth-controllable mechanisms for the insertion of single neura...
Article
This work presents an insect-scale microrobot that flies silently and with no mechanical moving parts, using a mechanism with no analogue in the natural world: electrohydrodynamic thrust produced by ions generated via corona discharge. For the first time, attitude and acceleration data is continuously collected from takeoff and sustained flight of...
Preprint
Objective: Microwire and Utah-style neural recording arrays are the predominant devices used for cortical neural recording, but the implanted electrodes cause a significant adverse biological response and suffer from well-studied performance degradation. Recent work has demonstrated that carbon fiber electrodes do not elicit this same adverse respo...
Article
Full-text available
The design of gaits for robot locomotion can be a daunting process which requires significant expert knowledge and engineering. This process is even more challenging for robots that do not have an accurate physical model, such as compliant or micro-scale robots. Data-driven gait optimization provides an automated alternative to analytical gait desi...
Conference Paper
We describe opportunities and challenges with wireless robotic materials. Robotic materials are multi-functional composites that tightly integrate sensing, actuation, computation and communication to create smart composites that can sense their environment and change their physical properties in an arbitrary programmable manner. Computation and com...
Article
Full-text available
We describe opportunities and challenges with wireless robotic materials. Robotic materials are multi-functional composites that tightly integrate sensing, actuation, computation and communication to create smart composites that can sense their environment and change their physical properties in an arbitrary programmable manner. Computation and com...
Article
Full-text available
Electrohydrodynamic thrust is an emerging propulsion mechanism for flying insect-scale robots. There is a need to both minimize the operating voltage and maximize the output force when designing microfabricated electrodes for use in these robots. In this work, an array of hybrid wire-needle and grid electrode geometries were fabricated and characte...
Article
We propose a crystal-free radio receiver exploiting a free-running oscillator as a Local Oscillator (LO) while simultaneously satisfying the 1% packet error rate specification of the IEEE 802.15.4 standard. This results in significant power savings for wireless communication in millimeter-scale microsystems targeting Internet of Things (IoT) applic...
Article
The IETF IPv6 over the time synchronized channel hopping mode of IEEE 802.15.4e (6TiSCH) working group standardizes a distributed mechanism for neighbor motes to agree on a schedule to communicate, driven by a scheduling function. This letter introduces the notion of housekeeping to the schedule function, in which motes relocate cells in the schedu...
Article
Full-text available
The miniaturization of integrated fluidic processors affords extensive benefits for chemical and biological fields, yet traditional, monolithic methods of microfabrication present numerous obstacles for the scaling of fluidic operators. Recently, researchers have investigated the use of additive manufacturing or “three-dimensional (3D) printing” te...
Article
Despite recent growth in the field of wearable devices, persistent collection of data with clear biomedical relevance remains elusive. The majority of products focus on short-term personal fitness metrics instead of long-term biomedical monitoring. The ideal wearable platform for researchers would include flexibility to test different biometric sen...