Control of Many Agents Using Few Instructions
01 Jan 2008-pp 352
TL;DR: This paper considers the problem of controlling a group of agents under the constraint that every agent must be given the same control input, relevant for the control of mobile micro-robots that all receive the same power and control signals through an underlying substrate.
Abstract: This paper considers the problem of controlling a group of agents under the constraint that every agent must be given the same control input This problem is relevant for the control of mobile micro-robots that all receive the same power and control signals through an underlying substrate Despite this restriction, several examples in simulation demonstrate that it is possible to get a group of micro-robots to perform useful tasks All of these tasks are derived by thinking about the relationships between robots, rather than about their individual states
Citations
More filters
TL;DR: This work presents a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks, and demonstrates how the robots exhibit a plethora of driving behaviors, how they can operate on a host of unstructured surfaces under both dry and wet conditions, andHow they can accomplish fully automated micromanipulation tasks.
Abstract: Primary challenges in the building of untethered submillimeter sized robots include propulsion methods, power supply, and control. We present a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks. The term MagMite is derived from Magnetic Miteâa tribute to the underlying magnetic propulsion principle and the micro-scale dimensions of the robot. The device harvests magnetic energy from the environment and effectively transforms it into inertia-and impact-driven mechanical force while being fully controllable. It can be powered and controlled with oscillating fields in the kilohertz range and strengths as low as 2 mT, which is only roughly 50 times the average Earth magnetic field. These microrobotic agents with dimensions less than 300 μm A 300 μm A 70 μm and a total mass of 30â50 μg are capable of moving forward, backward and turning in place while reaching controllable speeds in excess of 12.5 mm sâ1 or 42 times the robotâs body length per second. The robots produce enough force to push micro-objects of similar sizes and can be visually servoed through a maze in a fully automated fashion. The prototype devices exhibit an overall degree of flexibility, controllability, and performance unmatched by other microrobots reported in the literature. The robustness of the MagMites leads to high experimental repeatability, which in turn enabled us to successfully compete in the RoboCup 2007 and 2009 Nanogram competitions. In this work it is demonstrated how the robots exhibit a plethora of driving behaviors, how they can operate on a host of unstructured surfaces under both dry and wet conditions, and how they can accomplish fully automated micromanipulation tasks. Various micro-objects ranging from beads to biological entities have been successfully manipulated. To the same end, multi-agent studies have shown great promise to be used in cooperative tasks.
193 citations
Cites background from "Control of Many Agents Using Few In..."
...Strategies dealing with this problem have been proposed in the literature but remain largely untested (Bretl 2007)....
[...]
...Although strategies exist for multi-agent control in this scenario, the tasks that multiple agents can perform are restricted to functions such as meeting at the same location, gathering close together, and avoiding collision (Bretl 2007)....
[...]
TL;DR: In this article, the authors proposed a parallel micro-robots assembly scheme using stress-engineered MEMS microrobots, which can be controlled to dock compliantly together, forming planar structures several times this size.
Abstract: We present designs, theory, and results of fabrication and testing for a novel parallel microrobotic assembly scheme using stress-engineered MEMS microrobots. The robots are 240-280 mum times 60 mum times 7-20 mum in size and can be controlled to dock compliantly together, forming planar structures several times this size. The devices are classified into species based on the design of their steering arm actuators, and the species are further classified as independent if they can be maneuvered independently using a single global control signal. In this paper, we show that microrobot species are independent if the two transition voltages of their steering arms, i.e., the voltages at which the arms are raised or lowered, form a unique pair. We present control algorithms that can be applied to groups of independent microrobot species to direct their motion from arbitrary nondead-lock configurations to desired planar microassemblies. We present designs and fabrication for four independent microrobot species, each with a unique transition voltage. The fabricated microrobots are used to demonstrate directed assembly of five types of planar structures from two classes of initial conditions. We demonstrate an average docking accuracy of 5 mum and use self-aligning compliant interaction between the microrobots to further align and stabilize the intermediate assemblies. The final assemblies match their target shapes on average 96%, by area.
164 citations
Cites background from "Control of Many Agents Using Few In..."
...A related theoretical motion planning approach for systems with limited individual controllability has been recently presented by Bretl [37], showing that it is possible to use the relative distribution of identical agents controlled through a global signal to perform useful tasks....
[...]
...Available: http://www.wormbook.org [37] T. Bretl, “Control of many agents using few instructions,” in Proc....
[...]
Proceedings Article•
01 Jan 2008TL;DR: This work presents a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks, and exhibits an overall degree of flexibility, controllability, and performance unmatched by othermicrorobots reported in the literature.
Abstract: Primary challenges in the building of untethered submillimeter sized robots include propulsion methods, power supply, and control. We present a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks. The term MagMite is derived from Magnetic Miteâa tribute to the underlying magnetic propulsion principle and the micro-scale dimensions of the robot. The device harvests magnetic energy from the environment and effectively transforms it into inertia-and impact-driven mechanical force while being fully controllable. It can be powered and controlled with oscillating fields in the kilohertz range and strengths as low as 2 mT, which is only roughly 50 times the average Earth magnetic field. These microrobotic agents with dimensions less than 300 μm A 300 μm A 70 μm and a total mass of 30â50 μg are capable of moving forward, backward and turning in place while reaching controllable speeds in excess of 12.5 mm sâ1 or 42 times the robotâs body length per second. The robots produce enough force to push micro-objects of similar sizes and can be visually servoed through a maze in a fully automated fashion. The prototype devices exhibit an overall degree of flexibility, controllability, and performance unmatched by other microrobots reported in the literature. The robustness of the MagMites leads to high experimental repeatability, which in turn enabled us to successfully compete in the RoboCup 2007 and 2009 Nanogram competitions. In this work it is demonstrated how the robots exhibit a plethora of driving behaviors, how they can operate on a host of unstructured surfaces under both dry and wet conditions, and how they can accomplish fully automated micromanipulation tasks. Various micro-objects ranging from beads to biological entities have been successfully manipulated. To the same end, multi-agent studies have shown great promise to be used in cooperative tasks.
88 citations
Cites background from "Control of Many Agents Using Few In..."
...Strategies dealing with this problem have been proposed in the literature but remain largely untested (Bretl 2007)....
[...]
...Although strategies exist for multi-agent control in this scenario, the tasks that multiple agents can perform are restricted to functions such as meeting at the same location, gathering close together, and avoiding collision (Bretl 2007)....
[...]
TL;DR: Qualitative results from a scaled-up printed circuit board version of the specialized substrate operating on permanent magnets are presented and offer proof-of-concept results for the approach, and insights for practical implementations of such a system are reported.
Abstract: In this paper, a novel approach to achieving the independent control of multiple magnetic microrobots is presented. The approach utilizes a specialized substrate consisting of a fine grid of planar, MEMS-fabricated micro coils of the same size as the microrobots (≤ 500 μm). The coils can be used to generate real magnetic potentials and, therefore, attractive and repulsive forces in the workspace to control the trajectories of the microrobots. Initial work on modelling the coil and microrobot behavior is reported along with simulation results for navigating one and two microrobots along independent desired trajectories. Qualitative results from a scaled-up printed circuit board version of the specialized substrate operating on permanent magnets are presented and offer proof-of-concept results for the approach. These tests also provide insights for practical implementations of such a system, which are similarly reported. The ultimate goal of this work is to use swarms of independently controlled microrobots...
67 citations
TL;DR: Inspired by techniques in which human operators performed well, this work investigates controllers that use only the mean and variance of the swarm and proves that mean position is controllable and conditions under which variance is controLLable.
Abstract: Microrobotics has the potential to revolutionize many applications including targeted material delivery, assembly, and surgery. The same properties that promise breakthrough solutions—small size and large populations—present unique challenges for controlling motion. Robotic manipulation usually assumes intelligent agents, not particle systems manipulated by a global signal. To identify the key parameters for particle manipulation, we used a collection of online games in which players steer swarms of up to 500 particles to complete manipulation challenges. We recorded statistics from more than 10 000 players. Inspired by techniques in which human operators performed well, we investigate controllers that use only the mean and variance of the swarm. We prove that mean position is controllable and provide conditions under which variance is controllable. We next derive automatic controllers for these and a hysteresis-based switching control to regulate the first two moments of the particle distribution. Finally, we employ these controllers as primitives for an object manipulation task and implement all controllers on 100 kilobots controlled by the direction of a global light source.
28 citations
Cites methods from "Control of Many Agents Using Few In..."
...Limited position control was achieved in [18] and our previous work [19], but both used robots commanded in their local coordinate frame....
[...]
References
More filters
TL;DR: This work presents a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks, and demonstrates how the robots exhibit a plethora of driving behaviors, how they can operate on a host of unstructured surfaces under both dry and wet conditions, andHow they can accomplish fully automated micromanipulation tasks.
Abstract: Primary challenges in the building of untethered submillimeter sized robots include propulsion methods, power supply, and control. We present a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks. The term MagMite is derived from Magnetic Miteâa tribute to the underlying magnetic propulsion principle and the micro-scale dimensions of the robot. The device harvests magnetic energy from the environment and effectively transforms it into inertia-and impact-driven mechanical force while being fully controllable. It can be powered and controlled with oscillating fields in the kilohertz range and strengths as low as 2 mT, which is only roughly 50 times the average Earth magnetic field. These microrobotic agents with dimensions less than 300 μm A 300 μm A 70 μm and a total mass of 30â50 μg are capable of moving forward, backward and turning in place while reaching controllable speeds in excess of 12.5 mm sâ1 or 42 times the robotâs body length per second. The robots produce enough force to push micro-objects of similar sizes and can be visually servoed through a maze in a fully automated fashion. The prototype devices exhibit an overall degree of flexibility, controllability, and performance unmatched by other microrobots reported in the literature. The robustness of the MagMites leads to high experimental repeatability, which in turn enabled us to successfully compete in the RoboCup 2007 and 2009 Nanogram competitions. In this work it is demonstrated how the robots exhibit a plethora of driving behaviors, how they can operate on a host of unstructured surfaces under both dry and wet conditions, and how they can accomplish fully automated micromanipulation tasks. Various micro-objects ranging from beads to biological entities have been successfully manipulated. To the same end, multi-agent studies have shown great promise to be used in cooperative tasks.
193 citations
TL;DR: In this article, the authors proposed a parallel micro-robots assembly scheme using stress-engineered MEMS microrobots, which can be controlled to dock compliantly together, forming planar structures several times this size.
Abstract: We present designs, theory, and results of fabrication and testing for a novel parallel microrobotic assembly scheme using stress-engineered MEMS microrobots. The robots are 240-280 mum times 60 mum times 7-20 mum in size and can be controlled to dock compliantly together, forming planar structures several times this size. The devices are classified into species based on the design of their steering arm actuators, and the species are further classified as independent if they can be maneuvered independently using a single global control signal. In this paper, we show that microrobot species are independent if the two transition voltages of their steering arms, i.e., the voltages at which the arms are raised or lowered, form a unique pair. We present control algorithms that can be applied to groups of independent microrobot species to direct their motion from arbitrary nondead-lock configurations to desired planar microassemblies. We present designs and fabrication for four independent microrobot species, each with a unique transition voltage. The fabricated microrobots are used to demonstrate directed assembly of five types of planar structures from two classes of initial conditions. We demonstrate an average docking accuracy of 5 mum and use self-aligning compliant interaction between the microrobots to further align and stabilize the intermediate assemblies. The final assemblies match their target shapes on average 96%, by area.
164 citations
Proceedings Article•
01 Jan 2008TL;DR: This work presents a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks, and exhibits an overall degree of flexibility, controllability, and performance unmatched by othermicrorobots reported in the literature.
Abstract: Primary challenges in the building of untethered submillimeter sized robots include propulsion methods, power supply, and control. We present a novel type of microrobot called MagMite that utilizes a new class of wireless resonant magnetic micro-actuator that accomplishes all three tasks. The term MagMite is derived from Magnetic Miteâa tribute to the underlying magnetic propulsion principle and the micro-scale dimensions of the robot. The device harvests magnetic energy from the environment and effectively transforms it into inertia-and impact-driven mechanical force while being fully controllable. It can be powered and controlled with oscillating fields in the kilohertz range and strengths as low as 2 mT, which is only roughly 50 times the average Earth magnetic field. These microrobotic agents with dimensions less than 300 μm A 300 μm A 70 μm and a total mass of 30â50 μg are capable of moving forward, backward and turning in place while reaching controllable speeds in excess of 12.5 mm sâ1 or 42 times the robotâs body length per second. The robots produce enough force to push micro-objects of similar sizes and can be visually servoed through a maze in a fully automated fashion. The prototype devices exhibit an overall degree of flexibility, controllability, and performance unmatched by other microrobots reported in the literature. The robustness of the MagMites leads to high experimental repeatability, which in turn enabled us to successfully compete in the RoboCup 2007 and 2009 Nanogram competitions. In this work it is demonstrated how the robots exhibit a plethora of driving behaviors, how they can operate on a host of unstructured surfaces under both dry and wet conditions, and how they can accomplish fully automated micromanipulation tasks. Various micro-objects ranging from beads to biological entities have been successfully manipulated. To the same end, multi-agent studies have shown great promise to be used in cooperative tasks.
88 citations
TL;DR: Qualitative results from a scaled-up printed circuit board version of the specialized substrate operating on permanent magnets are presented and offer proof-of-concept results for the approach, and insights for practical implementations of such a system are reported.
Abstract: In this paper, a novel approach to achieving the independent control of multiple magnetic microrobots is presented. The approach utilizes a specialized substrate consisting of a fine grid of planar, MEMS-fabricated micro coils of the same size as the microrobots (≤ 500 μm). The coils can be used to generate real magnetic potentials and, therefore, attractive and repulsive forces in the workspace to control the trajectories of the microrobots. Initial work on modelling the coil and microrobot behavior is reported along with simulation results for navigating one and two microrobots along independent desired trajectories. Qualitative results from a scaled-up printed circuit board version of the specialized substrate operating on permanent magnets are presented and offer proof-of-concept results for the approach. These tests also provide insights for practical implementations of such a system, which are similarly reported. The ultimate goal of this work is to use swarms of independently controlled microrobots...
67 citations
TL;DR: Inspired by techniques in which human operators performed well, this work investigates controllers that use only the mean and variance of the swarm and proves that mean position is controllable and conditions under which variance is controLLable.
Abstract: Microrobotics has the potential to revolutionize many applications including targeted material delivery, assembly, and surgery. The same properties that promise breakthrough solutions—small size and large populations—present unique challenges for controlling motion. Robotic manipulation usually assumes intelligent agents, not particle systems manipulated by a global signal. To identify the key parameters for particle manipulation, we used a collection of online games in which players steer swarms of up to 500 particles to complete manipulation challenges. We recorded statistics from more than 10 000 players. Inspired by techniques in which human operators performed well, we investigate controllers that use only the mean and variance of the swarm. We prove that mean position is controllable and provide conditions under which variance is controllable. We next derive automatic controllers for these and a hysteresis-based switching control to regulate the first two moments of the particle distribution. Finally, we employ these controllers as primitives for an object manipulation task and implement all controllers on 100 kilobots controlled by the direction of a global light source.
28 citations