Xiaobo Tan's research while affiliated with Michigan State University and other places

Publications (305)

Article
Underwater gliders are known for their energy-efficiency and long-duration operations, with demonstrated applications in ocean exploration, fish tracking, and environmental sampling. Many applications such as exploring a large area of underwater ruins would benefit from accurate trajectory tracking. Trajectory tracking is particularly challenging f...
Article
Assessment of spawning-phase dynamics is an essential prerequisite to successful control of invasive sea lampreys in Great Lakes areas, which cause catastrophic damages in both commercial fishery and ecological systems. However, current assessment strategies may pose challenges for lake-wide abundance estimation and non-target anadromous species pr...
Article
We present a multi-material three-dimensional-printed snakeskin with orthotropic friction anisotropy, which permits undulatory slithering of a soft snake robot on rough surfaces. Such a snakeskin is composed of a soft skin base and embedded rigid scales attached to the robot's ventral surface. The bioinspired designs of scale shapes and arrangement...
Article
For mobile robots, localization is essential for navigation and spatial correlation of its collected data. However, localization in GPS-denied environments such as underwater has been challenging. LED-based optical localization has been proposed in literature, where the bearing angles extracted from the line-of-sight (LOS) of the robot viewed from...
Article
Robotic fish has received increasing attention in the last few decades, as they hold strong promise in a myriad of applications. Efficient and precise control of these robots, particularly accurate trajectory control, has become essential in many of these applications. This article proposes a dual-loop backstepping-based trajectory tracking control...
Article
We report a polypropylene (PP) based ferroelectret device with quasi-piezoelectricity features to measure negative pressures underwater. The device consists of a foam-structured middle layer with giant electric dipoles between two solid PP films. The quasi-piezoelectricity originates from the relative movement between two oppositely charged surface...
Article
Polyvinyl chloride (PVC) gels represent a novel type of electroactive polymer actuators with a number of appealing characteristics, including low cost, high compliance, large strain, medium-to-high stress output, fast response, and thermal stability. Despite their vast potential in a variety of applications, modeling and control of nonlinear dynami...
Article
In this paper, an economical and effective soft pressure sensor for underwater sea lamprey detection is proposed, which consists of an array of piezoresistive elements between two layers of perpendicular copper tape electrodes, forming a passive resistor network. With multiplexers, the apparent resistance corresponding to each pixel of the sensing...
Preprint
Full-text available
Recent advances in technology have renewed the interested in the impact of viscoelastic boundaries and active boundary modulation on hydrodynamic drag and boundary layer turbulence. Viscoelastic boundary materials, such as found in dolphin skin, have the potential to reduce frictional drag by delaying the transition from laminar to turbulent flow i...
Preprint
Designing effective rehabilitation strategies for upper extremities, particularly hands and fingers, warrants the need for a computational model of human motor learning. The presence of large degrees of freedom (DoFs) available in these systems makes it difficult to balance the trade-off between learning the full dexterity and accomplishing manipul...
Article
The conductivity and dielectric properties are integral to the function of polyvinyl chloride (PVC) gel actuators. The frequency-dependent properties of PVC gel actuators are investigated here in terms of their impedance, permittivity, and for the first time, electric modulus. The data shows that PVC gels’ conductive properties are just as, if not...
Article
We consider the tracking problem for an uncertain nonlinear single-input-single-output system satisfying the minimum-phase assumption, preceded by an unknown hysteresis operator. This is a widely used model for smart material-actuated systems, such as piezo-based nanopositioning systems. Existing hysteresis compensation methods typically require ex...
Article
This paper considers the problem of distributed state estimation of a linear time-invariant (LTI) system by a network of sensors in a discrete-time setting. Specifically, we consider a consensus-based distributed Kalman Filter (KF) where each sensor updates its estimate in two steps: a consensus step dictated by a weighted and directed communicatio...
Article
Increased interest in the use of autonomous aquatic robots in a variety of applications has led to the need for efficient and precise control of these robots. In particular, accurate trajectory control has become of importance in many of these applications. However, the highly nonlinear and underactuated dynamics of many aquatic robots present sign...
Article
Skin-like sensitivity, or the capability to recognize tactile information, is essential for future robots in elder care, housekeeping, search and rescue, entertainment and other applications involving unstructured environments. The fabrication of a sensitive skin consisting of thousands of pressure sensors is both mechanically complex and processin...
Article
LED-based free-space optical communication is becoming a promising alternative to the traditional acoustics mode of underwater communication because of its low cost, high data rate, and low power consumption. However, a fundamental challenge associated with the free space optical communication systems is to establish and maintain line-of-sight (LOS...
Article
The ability to monitor invasive sea lamprey (Petromyzon marinus) populations in the Laurentian Great Lakes is critical to protecting the region’s $\$ $ 7 billion USD fishing industry and preserving its biodiversity. Monitoring these invaders requires considerable fieldwork and human power, making remote lamprey detection systems attractive for th...
Article
Nanopositioning stages are widely used in high-precision positioning applications. However, they suffer from an intrinsic hysteretic behavior, which deteriorates their tracking performance. This study proposes an adaptive conditional servocompensator (ACS) to compensate the effect of the hysteresis when tracking periodic references. The nanopositio...
Article
Full-text available
Species-specific monitoring activities represent fundamental tools for natural resource management and conservation but require techniques that target species-specific traits or markers. Sea lamprey, a destructive invasive species in the Laurentian Great Lakes and conservation target in North America and Europe, is among very few fishes that posses...
Article
Full-text available
This paper presents a generalizable methodology for data-driven identification of nonlinear dynamics that bounds the model error in terms of the prediction horizon and the magnitude of the derivatives of the system states. Using higher-order derivatives of general nonlinear dynamics that need not be known, we construct a Koopman operator-based line...
Article
Acoustic-based techniques are the standard for localization and communication in underwater environments, but due to the challenges associated with this medium, it is becoming increasingly popular to find alternatives such as using optics. In our prior work we developed an LED-based Simultaneous Localization and Communication (SLAC) approach that u...
Article
Pectoral fins play an important role in the locomotion and maneuvering of robotic fish. Considering the cyclic nature of typical actuation modes, it is of interest to develop a dynamic average model that is amenable to controller design, where the control inputs are actuation pattern parameters. In this work, we propose a scaling-based approach to...
Article
Soft robotic manipulators have seen growing interest in recent years and have many applications in the medical and industrial fields. Path planning algorithms for these soft continuum arms often have features to include obstacle avoidance. The redundant nature of soft robots allows for these manipulators to avoid obstacles while moving towards a go...
Article
Polyvinyl chloride (PVC) gel-based actuators are a new class of soft, electroactive polymer actuators with several attractive properties, including low cost, large compliance, large strain output, high-stress output, fast response, and stability against thermal influence. While PVC gel actuators are quickly gaining attention, they remain largely un...
Article
Steerable drifters are a promising energy-efficient environmental sampling platform for aquatic environments with pronounced flows, such as rivers and lakes or oceans with circulation structures. Due to aging and environmental variability, the dynamics of a drifter are often uncertain, which poses challenges in achieving desired control of the robo...
Article
Full-text available
Background Autonomous underwater vehicles (AUVs) and animal telemetry have become important tools for understanding the relationships between aquatic organisms and their environment, but more information is needed to guide the development and use of AUVs as effective animal tracking platforms. A forward-facing acoustic telemetry receiver (VR2Tx 69...
Conference Paper
Localization of mobile robots is essential for navigation and data collection. This work presents an optical localization scheme for mobile robots during the robot’s continuous movement, despite that only one bearing angle can be captured at a time. In particular, this paper significantly improves upon our previous works where the robot has to paus...
Conference Paper
In this paper, we derive a dynamical model for a controllable flexible membrane which is point-actuated by distributed voice coil motors (VCM) connected to it. Besides the modal analysis of the membrane motion, which is the only dynamics discussed in most of related published works treating external pressures as inputs, we integrate the dynamics of...
Conference Paper
The problem of localizing a moving target arises in various forms in wireless sensor networks. Deploying multiple sensing receivers and using the time-difference-of-arrival (TDOA) of the target’s emitted signal is widely considered an effective localization technique. Traditionally, TDOA-based algorithms adopt a centralized approach where all measu...
Conference Paper
Drifters are energy-efficient platforms for monitoring rivers and oceans. Prior work largely focused on free-floating drifters that drift passively with flow and have little or no controllability. In this paper we propose steerable drifters that use multiple rudders for modulating the hydrodynamic forces and thus maneuvering. A dynamic model for dr...
Article
In this article, an adaptive conditional servocompensator is proposed to achieve precise tracking control of systems with hysteresis without requiring explicit inversion of the hysteresis. Motivated by a range of applications, such as the piezoelectric-actuated nanopositioning, the system considered in this work consists of a chain of integrators p...
Conference Paper
This paper proposes a highly stretchable strain sensor using viscous conductive materials as resistive element and introduces a simple and economic fabrication process by encapsulating the conductive materials between two layers of silicone rubbers Ecoflex 00-30. The fabrication process of the strain sensor is presented, and the properties of the v...
Conference Paper
Interest in soft robotics has increased in recent years due to their potential in a myriad of applications. A wide variety of soft robots has emerged, including bio-inspired robotic swimmers such as jellyfish, rays, and robotic fish. However, the highly nonlinear fluid-structure interactions pose considerable challenges in the analysis, modeling, a...
Preprint
We consider a scenario in which an autonomous vehicle equipped with a downward facing camera operates in a 3D environment and is tasked with searching for an unknown number of stationary targets on the 2D floor of the environment. The key challenge is to minimize the search time while ensuring a high detection accuracy. We model the sensing field u...
Article
Autonomous mobile robots operating in areas with poor GPS and wireless coverage (e.g., underwater) must rely on alternative localization and communication approaches. In this work, we present an LED-based system that achieves Simultaneous Localization and Communication (SLAC), where the line of sight (LOS) requirement for communication is exploited...
Article
Localization and tracking of a moving target arises in many different contexts and is of particular interest in the field of robotic networks. One important class of localization schemes exploits the time-difference-of-arrival (TDOA) of a signal emitted by the target and detected by multiple sensors. In this work, we propose a fully distributed app...
Article
In this paper we propose a novel pneumatic soft snake robot which exploits traveling-wave motion to move in complex, constrained environments such as a pipeline. The robot is modular, with a unique pneumatic system design that requires the use of only four air channels regardless of the number of modules. The robot is 3D-printed, and thus low-cost...
Article
Soft robots take advantage of rich nonlinear dynamics and large degrees of freedom to perform actions often by novel means beyond the capability of conventional rigid robots. Nevertheless, there are considerable challenges in analysis, design, and optimization of soft robots due to their complex behaviors. This is especially true for soft robotic s...
Article
Soft pressure sensors may find a wide range of applications in soft robotics, biomedical devices, and smart wearables. Here, an inkjet‐printed resistive pressure sensor that offers high sensitivity and can be fabricated using a very simple process is reported. The device is composed of a conductive silver nanoparticle (AgNP) layer directly printed...
Conference Paper
Full-text available
This paper presents a data-driven methodology for the linear embedding of nonlinear systems. Utilizing structural knowledge of general nonlinear dynamics, the authors exploit the Koopman operator to develop a systematic, data-driven approach for constructing a linear representation in terms of higher-order derivatives of the underlying nonlinear dy...
Conference Paper
This paper presents an adaptive, needle variation-based feedback scheme for controlling affine nonlinear systems with unknown parameters that appear linearly in the dynamics. The proposed approach combines an online parameter identifier with a second-order sequential action controller that has shown great promise for nonlinear, underactuated, and h...
Conference Paper
Autonomous underwater gliders have become valuable tools for a myriad of applications ranging from ocean exploration to fish tracking to environmental sampling. To be suitable for these types of applications, precise sensing and monitoring is desired, which makes accurate trajectory control important. However, highly nonlinear under-actuated dynami...
Conference Paper
Inflatable structures provide significant volume and weight savings for future space and soft robotic applications. Structural health monitoring (SHM) of these structures is essential to ensuring safe operation, providing early warnings of damage, and measuring structural changes over time. In this paper, we propose the design of a single flexible...
Article
Given a nonlinear dynamical system, this paper considers the problem of selecting a subset of the total set of sensors that has provable guarantees on standard metrics related to the nonlinear observability Gramian. The key contribution is a simple randomized algorithm that samples the sensors uniformly without replacement, and yields probabilistic...
Conference Paper
Smart material-based systems, such as piezo-electric nanopositioning stages, exhibit pronounced hysteresis nonlinearity that poses significant control challenges. Much of the existing work employs an inverse hysteresis operator to approximately cancel out the hysteresis nonlinearity. In this paper we propose an inversion-free approach to the contro...
Article
It is of interest to exploit the insight from the lateral line system of fish for flow sensing applications. In this paper, a novel fish canal lateral line-inspired pressure difference sensor is proposed by embedding an ionic polymer-metal composite (IPMC) sensor within a canal filled with viscous fluid. Such a sensor could be used by underwater ro...
Article
Full-text available
Soft pressure sensors are one class of the essential devices for robotics and wearable device applications. Despite the tremendous progress, sensors that can reliably detect both positive and negative pressures have not yet been demonstrated. In this paper, a soft capacitive pressure sensor, made using a convenient and low‐cost screen‐printing proc...
Article
To map the hemodynamic responses of kidney microstructures at 7.05 T with improved sensitivity, a Wireless Amplified NMR Detector (WAND) with cylindrical symmetry was fabricated as an endoluminal detector that can convert externally provided wireless signal at 600.71 MHz into amplified MR signals at 300.33 MHz. When this detector was inserted insid...
Article
There has been an increasing interest in the use of autonomous underwater robots to monitor freshwater and marine environments. In particular, robots that propel and maneuver themselves like fish, often known as robotic fish, have emerged as mobile sensing platforms for aquatic environments. Highly nonlinear and often under-actuated dynamics of rob...
Article
The field of soft robotics has seen increasing interest and developments in recent years. Stiffness tuning is a desirable characteristic for soft robots since it enables adaptively modulating the load-bearing capability, shape, and locomotion behavior of the robots. In this article a compact and cost-effective mechanism for stiffness tuning is prop...
Conference Paper
In recent years, gliding robotic fish have emerged as promising mobile platforms for underwater sensing and monitoring due to their notable energy efficiency and maneuverability. For sensing of aquatic environments, it is important to use efficient sampling strategies that incorporate previously observed data in deciding where to sample next so tha...
Conference Paper
Hysteresis is a nonlinearity exhibited by a wide class of smart materials, such as piezoelectrics and shape memory alloys, and it presents challenges in the control of smart material-actuated systems (for example, piezo-based nanopositioning systems). Existing methods for hysteresis compensation typically require an explicit model of the hysteresis...
Conference Paper
Stretchable strain sensors with large strain range, high sensitivity, and excellent reliability are of great interest for applications in soft robotics, wearable devices, and structure-monitoring systems. Unlike conventional template lithography-based approaches, 3D-printing can be used to fabricate complex devices in a simple and cost-effective ma...
Conference Paper
Full-text available
The hysteresis nonlinearity is widely exhibited in a variety of materials and systems. As a popular model, the Preisach operator has been adopted to capture both monotonic and non-monotonic hysteresis. Existing studies on the control of hysterestic systems predominantly rely on feedforward or feedback approaches that require a constantly applied in...
Article
Full-text available
Light-emitting diode (LED)-based optical communication is emerging as a low-power, low-cost and high-data rate alternative to acoustic communication for mobile applications underwater. However, it requires a close-to-line-of-sight link between the transmitter and the receiver. Alignment for maintaining line-of-sight (LOS) is challenging due to the...
Article
Ionic polymer-metal composites (IPMCs) have intrinsic sensing and actuation properties. Typical IPMC sensors are in the shape of beams and only respond to stimuli acting along beam-bending directions. Rod or tube-shaped IPMCs have been explored as omnidirectional bending actuators or sensors. In this paper, physics-based modeling is studied for a t...
Article
The programming of different mechanical states of a MEMS mirror is presented here. The mirror is based on a smart material called vanadium dioxide (VO₂) and actuated through Joule heating. The system exhibits dynamical and hysteresis nonlinearity. While hysteresis is largely deemed undesirable, in this paper, the hysteretic behavior of the VO₂ is e...
Conference Paper
Full-text available
Soft pressure sensors have a wide range of applications, such as aerodynamic control of cars and unmanned aerial vehicles, navigation of underwater vehicles, and wearable electronics. Existing soft pressure sensors are typically based on capacitive or resistive principles. However, these sensors, made of multiple layers of different materials, tend...
Article
Analyzing hysteretic systems presents a significant challenge due to the memory effect of hysteresis. In this paper we present an incremental harmonic balance (IHB)-based approach to compute the steady-state response of a closed-loop system with hysteresis under a sinusoidal excitation, where the hysteresis element is modeled by the Prandtl–Ishlins...
Conference Paper
Localization and tracking of a moving target arises in many different contexts and is an important problem in the field of wireless sensor networks. One class of localization schemes exploits the time-difference-of-arrival (TDOA) of a signal emitted by the target and detected by multiple sensors. Much of the existing work on TDOA-based target local...
Conference Paper
Full-text available
Maintaining Line-Of-Sight (LOS) between the receiver and the transmitter is an inherent challenge associated with light-emitting diode (LED)-based free space optical communication systems, especially when such systems are used by mobile robots. Due to constant movement of underlying robotic platforms and other unwanted disturbances, there is a need...
Conference Paper
Localization of mobile robots in GPS-denied envrionments (e.g., underwater) is of great importance to achieving navigation and other missions for these robots. In our prior work a concept of Simultaneous Localization And Communication (SLAC) was proposed, where the line of sight (LOS) requirement in LED-based communication is exploited to extract t...
Conference Paper
It is of interest to exploit the insight from the lateral line system of fish for flow sensing applications. The lateral line consists of arrays of flow sensors, known as neuromasts, with hair cells encased within a gel-like structure called cupula. There are two types of neuromasts, superficial neuromasts, which reside on the surface, and canal ne...