The advanced computing and communication between components within the intelligent transportation system creates vulnerabilities that can be exploited by bad actors. To ensure the safety of autonomous vehicles and sec...
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ISBN:
(纸本)9798350399462
The advanced computing and communication between components within the intelligent transportation system creates vulnerabilities that can be exploited by bad actors. To ensure the safety of autonomous vehicles and secure the infrastructure, we must first understand how a cyber attack propagates through the intelligent transportation system. This propagation occurs through communications between individual agents and entire subsystems. By understanding the impact of component and subsystem interactions, we can better fortify the intelligent transportation system against cyber attacks. This paper presents an agent-based model for detection of and recovery from cyber attacks on the intelligent transportation system for autonomous vehicles. In this model, vehicles, pedestrians, and intelligent infrastructure are represented as distinct agent populations. Simulations were run to test the spread of cyber attack while considering the origin and aggressiveness of the attack, and detection and defense capabilities. The simulations showed that clusters of distinct agents will form based on communication ranges. These clusters can quickly merge as new agents are introduced. Preventing the introduction of new agents can isolate subsystems affected by an attack.
A cyber-physical-social system (CPSS) is a brand-new paradigm of cyber-physical and cyber-social systems that integrates dynamic stochastic hybrid systems including computation, communication, sensing and actuation, a...
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This paper presents a new control scheme for cooperative dual-arm robots manipulating heavy objects. The proposed method uses the full dynamical model of the kinematically coupled robot system and builds on a hierarch...
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ISBN:
(纸本)9781665491907
This paper presents a new control scheme for cooperative dual-arm robots manipulating heavy objects. The proposed method uses the full dynamical model of the kinematically coupled robot system and builds on a hierarchical quadratic programming (HQP) formulation to enforce dynamical inequality constraints such as joint torques or internal loads. This ensures optimal tracking of an object trajectory, while additional objectives with lower priority are optimized on the prior solution space. Therefore, the redundancy of the inherent load distribution problem between the two arms can be eliminated. With this approach, higher object loads can be manipulated compared to non-optimized methods. Simulations with a 14 degree of freedom (dof) dual-arm robotic system demonstrate the effectiveness of the proposed control method. The real-time feasibility is guaranteed with an average computation time of less than 0.35 milliseconds at a control rate of 1 kilohertz.
One degree-of-freedom (1DOF) nonlinear vibration isolators have better vibration-damping performance than 1DOF linear isolators, but the former has an inherent flaw, that is, when the excitation disappears, the load c...
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An increase in the number of power consumers leads to scale up a power supply grids, and the introduction of Smart Grid (SG) for connecting components and subsystems of distributed generation, increases the complexity...
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In order for a humanoid robot to balance on the movable ground, balance feedback control in response to its unpredictable movement is required. However, feedback control in response to ground movement has the followin...
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ISBN:
(纸本)9781665491907
In order for a humanoid robot to balance on the movable ground, balance feedback control in response to its unpredictable movement is required. However, feedback control in response to ground movement has the following two issues, (A) Interaction between the ground dynamics and the balance control may cause vibration. (B) The balance control may rather deteriorate the stability due to the response delay. To solve these problems, this study proposes the support foot acceleration term in the walking stabilizer and gives its gain by considering the following two conditions, (A) Avoiding steady-state vibration in a two-mass linear inverted pendulum model on an arbitrary ground, and (B) reducing the influence of inertial forces resulting from the delay of ZMP feedback. Experiments with a life-size humanoid JAXON verified the steady-state vibration phenomenon and improved the stability of acceleration and deceleration when boarding the Two-Wheeled Scooter.
Rocket recycling is a crucial pursuit in aerospace technology, aimed at reducing costs and environmental impact in space exploration. The primary focus centers on rocket landing control, involving the guidance of a no...
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ISBN:
(纸本)9798350377712;9798350377705
Rocket recycling is a crucial pursuit in aerospace technology, aimed at reducing costs and environmental impact in space exploration. The primary focus centers on rocket landing control, involving the guidance of a nonlinear underactuated rocket with limited fuel in real-time. This challenging task prompts the application of reinforcement learning (RL), yet goal-oriented nature of the problem poses difficulties for standard RL algorithms due to the absence of intermediate reward signals. This paper, for the first time, significantly elevates the success rate of rocket landing control from 8% with a baseline controller to 97% on a high-fidelity rocket model using RL. Our approach, called Random Annealing Jump Start (RAJS), is tailored for real-world goal-oriented problems by leveraging prior feedback controllers as guide policy to facilitate environmental exploration and policy learning in RL. In each episode, the guide policy navigates the environment for the guide horizon, followed by the exploration policy taking charge to complete remaining steps. This jump-start strategy prunes exploration space, rendering the problem more tractable to RL algorithms. The guide horizon is sampled from a uniform distribution, with its upper bound annealing to zero based on performance metrics, mitigating distribution shift and mismatch issues in existing methods. Additional enhancements, including cascading jump start, refined reward and terminal condition, and action smoothness regulation, further improve policy performance and practical applicability. The proposed method is validated through extensive evaluation and Hardware-in-the-Loop testing, affirming the effectiveness, real-time feasibility, and smoothness of the proposed controller.
Real-time interception of fast-moving objects by robotic arms in dynamic environments poses a formidable challenge due to the need for rapid reaction times, often within milliseconds, amidst dynamic obstacles. This pa...
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ISBN:
(纸本)9798350377712;9798350377705
Real-time interception of fast-moving objects by robotic arms in dynamic environments poses a formidable challenge due to the need for rapid reaction times, often within milliseconds, amidst dynamic obstacles. This paper introduces a unified control framework to address the above challenge by simultaneously intercepting dynamic objects and avoiding moving obstacles. Central to our approach is using diffusion-based variational autoencoder for motion planning to perform both object interception and obstacle avoidance. We begin by encoding the high-dimensional temporal information from streaming events into a two-dimensional latent manifold, enabling the discrimination between safe and colliding trajectories, culminating in the construction of an offline densely connected trajectory graph. Subsequently, we employ an extended Kalman filter to achieve precise real-time tracking of the moving object. Leveraging a graph-traversing strategy on the established offline dense graph, we generate encoded robotic motor control commands. Finally, we decode these commands to enable real-time motion of robotic motors, ensuring effective obstacle avoidance and high interception accuracy of fast-moving objects. Experimental validation on both computer simulations and autonomous 7-DoF robotic arms demonstrates the efficacy of our proposed framework. Results indicate the capability of the robotic manipulator to navigate around multiple obstacles of varying sizes and shapes while successfully intercepting fast-moving objects thrown from different angles by hand. Complete video demonstrations of our experiments can be found in https://***/view/multirobotskill/home.
We propose novel symmetry-based modeling and hybrid orientation-force control frameworks for cutaneous haptic device (CHD) to generate precise three degree-of-freedom (DoF) contact force on the fingertip robustly agai...
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ISBN:
(纸本)9781665491907
We propose novel symmetry-based modeling and hybrid orientation-force control frameworks for cutaneous haptic device (CHD) to generate precise three degree-of-freedom (DoF) contact force on the fingertip robustly against user variability. The CHD hardware is designed in a form of an underactuated cable-driven parallel mechanism, with springs placed along the tendon to stabilize the pose. We analyze the kinematics of the CHD and propose a pose estimator by exploiting the symmetrical nature of the mechanism. We then devise a hybrid orientation-force controller to track the direction and magnitude of the desired contact force simultaneously in a feedback manner for control accuracy and robustness. We also adopt a tension regulator to mitigate friction effect during the actuation. Experimental validation and demonstration show the efficacy of the CHD with our proposed estimation and control framework.
control centers for automated vehicle fleets (CC-AVFs) are pivotal in enabling autonomous driving at a large scale. This work conducts a holistic survey of CC-AVFs, focusing on European studies. It discusses operation...
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ISBN:
(纸本)9798350399462
control centers for automated vehicle fleets (CC-AVFs) are pivotal in enabling autonomous driving at a large scale. This work conducts a holistic survey of CC-AVFs, focusing on European studies. It discusses operational concepts, requirements, architectures, transmission technologies, monitoring, and remote operation methods. Additionally, we present a design concept for CC-AVFs that structures the outlined topics and addresses dependencies. This paper connects the fragmented literature regarding CC-AVFs and gives design considerations to guide future research for efficient and safe CC-AVF implementation in contexts such as public transport.
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