Controls and Control Theory Commons^™

Improving Manufacturing Processes Through Energy Monitoring, Andrew Grzelak

Purdue Polytechnic Masters Theses

Energy efficiency and sustainability are very popular topics in the current field of manufacturing. With the increase in use of automation technology as well as the recent growth in the area of energy management, there is much focus on the overall improvement of manufacturing processes. For this research a project was completed to create a system that could improve both process efficiency as well as decrease energy consumption. By taking a look at the machine level energy consumption of an automated piece of manufacturing equipment, by eliminating waste in process, both energy efficiency and operational efficiency can be improved.

Using …

Disturbance Detection, Identification, And Recovery By Gait Transition In Legged Robots, Aaron M. Johnson, Galen Clark Haynes, Daniel E. Koditschek

Daniel E Koditschek

We present a framework for detecting, identifying, and recovering within stride from faults and other leg contact disturbances encountered by a walking hexapedal robot. Detection is achieved by means of a software contactevent sensor with no additional sensing hardware beyond the commercial actuators’ standard shaft encoders. A simple finite state machine identifies disturbances as due either to an expected ground contact, a missing ground contact indicating leg fault, or an unexpected “wall” contact. Recovery proceeds as necessary by means of a recently developed topological gait transition coordinator. We demonstrate the efficacy of this system by presenting preliminary data arising from …

Sprawl Angle In Simplified Models Of Vertical Climbing: Implications For Robots And Roaches, Goran A. Lynch, Lawrence Rome, Daniel E. Koditschek

Daniel E Koditschek

Empirical data taken from fast climbing sprawled posture animals reveals the presence of strong lateral forces with significant pendulous swaying of the mass center trajectory in a manner captured by a recently proposed dynamical template. In this simulation study we explore the potential benefits of pendulous dynamical climbing in animals and in robots by examining the stability and power advantages of variously more and less sprawled limb morphologies when driven by conventional motors in contrast with animal-like muscles. For open loop models of gait generation inspired by the neural-deprived regimes of high stride-frequency animal climbing, our results corroborate earlier hypotheses …

Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas

George J. Pappas

We consider deployment problems where a mobile robotic network must optimize its configuration in a distributed way in order to minimize a steady-state cost function that depends on the spatial distribution of certain probabilistic events of interest. Three classes of problems are discussed in detail: coverage control problems, spatial partitioning problems, and dynamic vehicle routing problems. Moreover, we assume that the event distribution is a priori unknown, and can only be progressively inferred from the observation of the location of the actual event occurrences. For each problem we present distributed stochastic gradient algorithms that optimize the performance objective. The stochastic …

Adaptive Robot Deployment Algorithms, Jerome Le Ny, George J. Pappas

George J. Pappas

In robot deployment problems, the fundamental issue is to optimize a steady state performance measure that depends on the spatial configuration of a group of robots. For static deployment problems, a classical way of designing high- level feedback motion planners is to implement a gradient descent scheme on a suitably chosen objective function. This can lead to computationally expensive deployment algorithms that may not be adaptive to uncertain dynamic environments. We address this challenge by showing that algorithms for a variety of deployment scenarios in stochastic environments and with noisy sensor measurements can be designed as stochastic gradient descent algorithms, …

The Wireless Control Network: Monitoring For Malicious Behavior, Shreyas Sundaram, Miroslav Pajic, Christoforos N. Hadjicostis, Rahul Mangharam, George J. Pappas

George J. Pappas

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. In a companion paper, we developed a protocol where each node repeatedly transmits a linear combination of the values in its neighborhood. For certain topologies, we showed that these linear combinations can be designed so that the closed loop system is stable (i.e., the wireless network itself acts as a controller for the plant). In this paper, we design a Intrusion Detection System (IDS) for this control scheme, which observes the transmissions of certain nodes in the network and uses that information to (a) …

Topological Conditions For Wireless Control Networks, Miroslav Pajic, Shreyas Sundaram, George J. Pappas, Rahul Mangharam

George J. Pappas

We study the problem of stabilizing a linear system over a wireless control network. We propose a scheme where each wireless node maintains a scalar state, and periodically updates it as a linear combination of neighboring plant outputs and node states. We make connections to decentralized fixed modes and structured system theory to provide conditions on the network topology that allow the system to be stabilized. Our analysis provides the minimal number of feedback edges that have to be introduced to stabilize the system over a network, and shows that as long as the network connectivity is larger than the …

Network Synthesis For Dynamical System Stabilization, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam

George J. Pappas

We present our recent results in the area of distributed control over wireless networks. In our previous work, we introduced the concept of a Wireless Control Network (WCN), where the network acts as a decentralized structured controller. In this case, the network is not used only as a communication medium (as in traditional control paradigms), but instead as a fully distributed computational substrate. We show that the dynamics of the plant dictate the types of network topologies that can be used to stabilize the system. Finally, we describe how to obtain a stabilizing configuration for the WCN if the topological …

A Simple Distributed Method For Control Over Wireless Networks, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam

George J. Pappas

We present a distributed scheme used for control over wireless networks. In our previous work, we introduced the concept of a Wireless Control Network (WCN), where the network itself, with no centralized node, acts as the controller. In this work, we show how the WCN can be modified to include observer style updates which substantially improves robustness of the closed-loop system to link failures. In addition, we analyze how the WCN simplifies extraction of the communication and computation schedules and enables system compositionality and scalability.

The Wireless Control Network: Synthesis And Robustness, Miroslav Pajic, Shreyas Sundaram, Jerome Le Ny, George J. Pappas, Rahul Mangharam

George J. Pappas

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. Traditional networked control schemes are designed with one of the nodes in the network acting as a dedicated controller, while the other nodes simply route information to and from the controller and the plant. We introduce the concept of a Wireless Control Network (WCN) where the entire network itself acts as the controller. Specifically, at each time-step, each node updates its internal state to be a linear combination of the states of the nodes in its neighborhood. We show that this causes the entire …

The Wireless Control Network: A New Approach For Control Over Networks, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam

George J. Pappas

We present a method to stabilize a plant with a network of resource constrained wireless nodes. As opposed to traditional networked control schemes where the nodes simply route information to and from a dedicated controller (perhaps performing some encoding along the way), our approach treats the network itself as the controller. Specifically, we formulate a strategy for each node in the network to follow, where at each time-step, each node updates its internal state to be a linear combination of the states of the nodes in its neighborhood. We show that this causes the entire network to behave as a …

Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas

George J. Pappas

We consider deployment problems where a mobile robotic network must optimize its configuration in a distributed way in order to minimize a steady-state cost function that depends on the spatial distribution of certain probabilistic events of interest. Three classes of problems are discussed in detail: coverage control problems, spatial partitioning problems, and dynamic vehicle routing problems. Moreover, we assume that the event distribution is a priori unknown, and can only be progressively inferred from the observation of the location of the actual event occurrences. For each problem we present distributed stochastic gradient algorithms that optimize the performance objective. The stochastic …

Adaptive Robot Deployment Algorithms, Jerome Le Ny, George J. Pappas

George J. Pappas

In robot deployment problems, the fundamental issue is to optimize a steady state performance measure that depends on the spatial configuration of a group of robots. For static deployment problems, a classical way of designing high- level feedback motion planners is to implement a gradient descent scheme on a suitably chosen objective function. This can lead to computationally expensive deployment algorithms that may not be adaptive to uncertain dynamic environments. We address this challenge by showing that algorithms for a variety of deployment scenarios in stochastic environments and with noisy sensor measurements can be designed as stochastic gradient descent algorithms, …

The Wireless Control Network: Monitoring For Malicious Behavior, Shreyas Sundaram, Miroslav Pajic, Christoforos N. Hadjicostis, Rahul Mangharam, George J. Pappas

George J. Pappas

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. In a companion paper, we developed a protocol where each node repeatedly transmits a linear combination of the values in its neighborhood. For certain topologies, we showed that these linear combinations can be designed so that the closed loop system is stable (i.e., the wireless network itself acts as a controller for the plant). In this paper, we design a Intrusion Detection System (IDS) for this control scheme, which observes the transmissions of certain nodes in the network and uses that information to (a) …

Topological Conditions For Wireless Control Networks, Miroslav Pajic, Shreyas Sundaram, George J. Pappas, Rahul Mangharam

George J. Pappas

We study the problem of stabilizing a linear system over a wireless control network. We propose a scheme where each wireless node maintains a scalar state, and periodically updates it as a linear combination of neighboring plant outputs and node states. We make connections to decentralized fixed modes and structured system theory to provide conditions on the network topology that allow the system to be stabilized. Our analysis provides the minimal number of feedback edges that have to be introduced to stabilize the system over a network, and shows that as long as the network connectivity is larger than the …

Network Synthesis For Dynamical System Stabilization, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam

George J. Pappas

We present our recent results in the area of distributed control over wireless networks. In our previous work, we introduced the concept of a Wireless Control Network (WCN), where the network acts as a decentralized structured controller. In this case, the network is not used only as a communication medium (as in traditional control paradigms), but instead as a fully distributed computational substrate. We show that the dynamics of the plant dictate the types of network topologies that can be used to stabilize the system. Finally, we describe how to obtain a stabilizing configuration for the WCN if the topological …

A Simple Distributed Method For Control Over Wireless Networks, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam

George J. Pappas

We present a distributed scheme used for control over wireless networks. In our previous work, we introduced the concept of a Wireless Control Network (WCN), where the network itself, with no centralized node, acts as the controller. In this work, we show how the WCN can be modified to include observer style updates which substantially improves robustness of the closed-loop system to link failures. In addition, we analyze how the WCN simplifies extraction of the communication and computation schedules and enables system compositionality and scalability.

The Wireless Control Network: Synthesis And Robustness, Miroslav Pajic, Shreyas Sundaram, Jerome Le Ny, George J. Pappas, Rahul Mangharam

George J. Pappas

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. Traditional networked control schemes are designed with one of the nodes in the network acting as a dedicated controller, while the other nodes simply route information to and from the controller and the plant. We introduce the concept of a Wireless Control Network (WCN) where the entire network itself acts as the controller. Specifically, at each time-step, each node updates its internal state to be a linear combination of the states of the nodes in its neighborhood. We show that this causes the entire …

The Wireless Control Network: A New Approach For Control Over Networks, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam

George J. Pappas

We present a method to stabilize a plant with a network of resource constrained wireless nodes. As opposed to traditional networked control schemes where the nodes simply route information to and from a dedicated controller (perhaps performing some encoding along the way), our approach treats the network itself as the controller. Specifically, we formulate a strategy for each node in the network to follow, where at each time-step, each node updates its internal state to be a linear combination of the states of the nodes in its neighborhood. We show that this causes the entire network to behave as a …

Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas

George J. Pappas

We consider deployment problems where a mobile robotic network must optimize its configuration in a distributed way in order to minimize a steady-state cost function that depends on the spatial distribution of certain probabilistic events of interest. Three classes of problems are discussed in detail: coverage control problems, spatial partitioning problems, and dynamic vehicle routing problems. Moreover, we assume that the event distribution is a priori unknown, and can only be progressively inferred from the observation of the location of the actual event occurrences. For each problem we present distributed stochastic gradient algorithms that optimize the performance objective. The stochastic …