This paper proposes a hybrid controller for a seat suspension equipped with an advanced electromagnetic damper (EMD) system to meet the requirement with vibration isolation and energy saving. The friction of seat suspension has considerable influence on the system dynamic. Applying a constant model to describe the friction is unreliable due to the long term wear and tear. Therefore, an observer is

A hardware-in-the-loop (HIL) docking simulator is an important validation facility on the ground for space docking. To reproduce the space docking process, the HIL docking simulator needs to solve the simulation distortion problem. In this paper, a force and moment compensation approach is presented to achieve a high-fidelity HIL simulation for a six degree-of-freedom docking simulator. The whole loop

In this paper, a novel method for early estimation of a human’s action intention is presented. Human intention, modeled as a goal location associated with a hand motion and eye gaze dynamics, is inferred by fusing information from collected hand motion and gaze motion data. The algorithm, called Human Intention Estimator with Variable Structure (HIEVS), uses two variable structure Interacting Multiple

Foot drop is the inability to dorsiflex the ankle (raise the toes) due to neuromuscular impairment, and this common condition can cause trips and falls. Current treatments for chronic foot drop provide dorsiflexion support, but they either impede ankle push off or are not suitable for all patients. Powered ankle-foot orthosis (AFO) can counteract foot drop without these drawbacks, but they are heavy

This paper discusses the motion control problem of kinematically redundant hybrid parallel robots that were recently proposed. The kinematic and dynamic models are firstly reviewed. It is pointed out that the robot can be decomposed into two parts and that each part can be analysed independently. A new hybrid approach is proposed based on this property of the robot. This approach includes an adapted

This paper presents a modeling framework for permanent magnet linear synchronous motors based on magnetic equivalent circuits. In comparison to the commonly used dq0 model, the proposed modeling approach is able to systematically include magnetic saturation effects and has no restriction to harmonic motor quantities. In contrast to existing work, a differential magnetic equivalent circuit network is

A novel sliding mode control combined with extended state observer (ESO) is proposed for an ankle exoskeleton driven by electrical motor. During the process of assisting, it is necessary to design an effective controller for assisting torque of ankle exoskeleton. However, the parameter uncertainty of complex dynamics model and the irregular motion of human ankle may affect the torque control accuracy

We describe a novel 3D path following control framework for articulated robots in applications where constant speed travel along a path is desirable, such as robotic surface finishing tasks. Given the desired robot configuration sequence with a list of waypoints along a path, a trajectory optimization scheme based on direct collocation is proposed to determine the Cartesian path and the maximum constant

To solve the problem of the control accuracy in electrohydraulic loading systems caused by load increment, this paper proposes a multi-cylinder electrohydraulic digital loading (MEDL) technology for accurate reproduction of large load. A traditionally used single cylinder loading (SCL) is replaced by a new hydraulic cylinders group that includes N hydraulic cylinders at each point, in which one is

Reactive multi-robot manipulation can be of great assistance in many applications. In this article a distributed cooperation strategy for object manipulation with multiple robots in un-modelled environments is proposed to tackle workpiece transportation and dynamic obstacle avoidance simultaneously. A decentralised optimisation process will run first to generate robot pose references and then a joint-level

Robotic manipulation of objects using the sole tactile feedback is a challenge. If the contact between the robot end effector and the manipulated object is distributed, the robot can exchange both friction forces and torques with it. The friction highly influences the motion of the object. By controlling the friction it is possible to perform complex manipulation tasks, such as moving the object with

This article deals with a robust self-balancing control scheme for the Two-In-Wheeled Self-Balancing Electric-Vehicle (TIW-SB-EV). Due to time-varying and unknown torque load, uncertainties on system parameters, and the lack of knowledge of the friction components, the approach proposes the design and implementation of an active disturbance rejection control based on the extended state observer (ESO)

This paper presents a new scheme of adaptive sliding mode control (ASMC) for a piezoelectric ultrasonic motor driven X–Y stage to meet the demand of precision motion tracking while addressing the problems of unknown nonlinear friction and model uncertainties. The system model with Coulomb friction and unilateral coupling effect is first investigated. Then the controller is designed with adaptive laws

Precision mechatronics and nanotechnology communities can both benefit from a course centered around an Atomic Force Microscope (AFM). Developing an AFM can provide precision mechatronics engineers with a valuable multidisciplinary hands-on training experience. In return, such expertise can be applied to the design and implementation of new precision instruments, which helps nanotechnology researchers

In order to facilitate a ball-joint-like spherical motor to operate with positioning systems to offer cascaded 6-DOF motion, a control method for precisely manipulating the spherical motor orientation in moving frame is proposed. By characterizing the cascaded motion with a pendulum-cart model, the rotor dynamics operated in moving frame is formulated. The properties of the dynamic model and the system

In nanopositioning systems with capacitive displacement sensors, the analog-to-digital (A/D) conversion time is not negligible, particularly for the sub-nano resolution cases with 16 (or more) digital bits. The sensor induced delay will complicate modeling and control of such systems, due to the infinite dimensionality of the delay block. In this paper, we analyze the piezoelectric nanopositioner with

This article describes a monolithic nanopositioner constructed from in-plane bending actuators which provide greater deflection than previously reported extension actuators, at the expense of stiffness and resonance frequency. The proposed actuators are demonstrated by constructing an XY nanopositioning stage with a serial kinematic design. Analytical modeling and finite-element-analysis accurately

To examine the influence of the configuration of a cable-driven parallel robot (CDPR) on its stiffness and stiffness controllability, a concept for a cable tension constraint workspace (CTCW) of CDPRs is introduced. Using a static force analysis, a static CDPR model was established and its stiffness model and a method for optimizing the cable tension were reviewed. To analyze and appraise the CDPR

In autonomous vehicles the driver will become a passenger. By ensuring a high level of ride comfort through active suspensions, the driver's ability to perform various tasks such as reading, drawing and texting can be enhanced. A high-performance shaker rig can conveniently be used to test the ride comfort improvement by means of various active suspensions under laboratory conditions. The paper deals

Robots are an indispensable part of modern production lines. Usually working in designated areas, they are separated from human workers in order to avoid collisions. A safe collaborative work environment is enabled by so-called soft robots, which constitute a human-friendly alternative to classical rigid industrial robots. However, modeling soft robots proves difficult and results in a lack of accuracy

Dynamic links of high-precision stage systems consist of wires and hoses that are used for example to transport electrical current to the actuators and sensors or cooling liquids to the stages. During stage motion, these dynamic links typically express complex hysteretic behavior due to internal friction and viscoelastic properties. As such, dynamic links give rise to unwanted disturbances acting on

In the paper, the event-based switching controller (ESC) is utilized to achieve better tracking performance compared with the neural network controller in circumstance of parameter uncertainty and unknown disturbance for the parallel manipulator. The ESC optimizes the choice of the neural weights by combining the prior knowledge of the system dynamics and the estimation of the system parameters. To

Percutaneous nephrolithotomy is a procedure used to treat patients with large or irregularly shaped kidney stones. Surgical instruments are inserted through a small incision to access the kidney and remove the calculi. Surgeons who have less experience with the procedure manifest significantly higher rates of complications due to the procedure’s steep learning curve. This issue is further exacerbated

Elastic manipulators often result from lightweight construction or safety requirements in human–robot-collaboration scenarios. In many cases, vibration-damping becomes necessary to enable stable and precise operation, which imposes high demands on controllers. A fundamental challenge for link-elastic manipulators with general kinematics and no dedicated damping actuators is the potential inability

In manufacturing automation, there is a strong need for highly integrated intelligent components and subsystems. In this context, a novel two-stage pneumatic piezoelectric-actuated valve has recently been developed. It covers a wide range of pneumatic products and functions in one compact component and enables flexible and adaptive plant operation. The valve consists of four poppet main-stage valves

This paper presents an optimized design and motion planning method of a hydraulically driven leg for jumping. The knee joint range was enlarged, and the desired torque profile was achieved using a four-bar linkage. The dynamics of the robot were considered during the motion planning, and the optimal trajectory was obtained by linear programming. Simulations and experiments showed that the leg could

Vehicle-to-Vehicle communication can cogently improve traffic safety because it grants drivers better situational awareness and strengthens inter-cooperation among them. However, the current policy obliges the safety-critical messages, i.e., Basic Safety Messages (BSMs) and Event Safety Messages (ESMs), to be transmitted exclusively in one single channel over the Dedicated Short-Range Communication

The electro-hydraulic servo steering system (EHSSS) is the key element to determine the handling and stability of heavy vehicles. Accurate steering control is challenged due to its complicated structure and a wide range of steering loads. In this paper, an output feedback integral sliding mode control (ISMC) method based on high-gain observer is proposed to solve this issue. First, a new Hurwitz matrix

This paper presents a piecewise constant strain kinematic model for concentric tube robots (CTR) in externally loaded conditions. It discretizes the pre-curved tubes comprising the robot into a finite number of pieces and involves external effects as a set of wrench vectors exerted along the robot backbone. Constant strain lets us describe the pieces with helices in which shear deformation and elongation

Since under-inflated wheels may lead to unsafe driving conditions, in many countries all the new cars must be equipped with tire pressure monitoring systems (TPMS). Such devices can be “direct”, in case air pressure sensors are employed, or “indirect”, if low tires are detected by comparing relative wheel speeds, typically via already available speed sensors. While the former are perfectly suited but

This paper focuses on the vibration rejection problem for the nonminimum-phase long-distance laser pointing system on the moving platform. Due to the unstable approximate inverse of nonminimum-phase property, the disturbance-observer based control (DOBC) methods inevitably sacrifice numerous vibration rejection capabilities to stabilize the system. In this paper, a compensatory disturbance-observer-based

Table tennis has long fascinated roboticists as a particularly difficult task which requires fast movements, accurate control and adaptation to task parameters. In addition, the development of such devices is useful for educating the undergraduate students. Up to now, several groups have developed robotic manipulators playing table tennis and other commercial interactive robots. Moreover, drones are

Common error sources of industrial robot manipulators include joint servoing error, imprecise kinematics, mechanical compliance, and transmission error. In this work we present a nested loop iterative learning control (ILC) feedforward structure: an inner loop that compensates for motor dynamics, and an outer loop that corrects the deviation along the path tracked, that features practically efficient

In this paper, a novel robotic assistive system (RAS) for mobility assistance of elderly adults is developed based on admittance control with force exertion ability enhancement (FEAE) of a wheeled mobile manipulator (WMM). The RAS can provide supportive force in the vertical direction and be guided by the user with a limited horizontal plane ability. An admittance controller is adopted to realize compliant

This paper presents an efficient and accurate dynamical model of reluctance actuators, suitable for prediction and control applications. It is a hybrid lumped-parameter state-space model that takes into account the mechanical and electromagnetic dynamics, including eddy currents, flux fringing, magnetic hysteresis and saturation. Special emphasis is placed on the hysteresis model, which is based on

Safe physical human-robotic interaction is a crucial concern for worn exoskeletons where lower weight requirement limits the number and size of actuators to be used. A novel control strategy is suggested in this paper for the low degree of freedom exoskeletons, by combining proposed mechanically decoupled passive-compliant arm-supports with active compliance, to achieve an improved and safer physi

This paper presents a new method of disturbance observer-based control (DOBC) for multi-input-multi-output (MIMO) highly-coupled unstable systems. In contrast to the current input–output approach for stable single-input-single-output (SISO) systems, the Youla parameterization of stabilizing controllers by full order state observer (FOSO) feedback control is shown more appropriate for general MIMO systems

A microsurgery-specific haptic interface with articulated structure, possessing 3 active, 4 passive and 3 supplementary degrees of freedom (DOFs), was designed and developed. The system includes a 3-DOF active serial linkage design, mimicking the human upper extremity. It is combined with a microsurgery-specific end-effector, comprised of a 3-DOF passive gimbal mechanism and a 1-DOF passive exchangeable

A Hydraulic Variable Valve Actuation (HVVA) system is studied in this work, it can continuously adjust engine valve timing and lift at any engine speeds by using a hydraulic actuation system. A detailed co-simulation model is built to reveal relationship between hydraulic pressure, engine valve lift and power consumption, it has taken flow rate, fluid property and pressure drop into consideration.

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 used the bearing angles, needed for establishing optical

Colonoscopy is a common procedure to perform advanced therapies such as Endoscopic Submucosal Dissection (ESD), which allows for greater diagnostic specificity and sensitivity compared to other types of examination. Nevertheless, since the colonoscope can cause patient discomfort or pain due to improper manipulation, it is quite challenging for endoscopists who need to develop the necessary skills

This paper presents a methodology for height and yaw angle control of a quadrotor that transports an unknown constant load added before the flight. Based on measurements from the onboard sensors, estimates of inertial parameters – mass and z-axis inertia – and state variables – vertical position, velocity, yaw angle and rate – are provided resorting to Multiple-Model Adaptive Estimators. The number

Research on the robustness of clutch engagement control is attracting considerable interest because of its wide applications in advanced powertrains. Internal model control (IMC) is advantageous because it can handle model errors and external disturbances with light computational loads. However, during clutch engagement, two control inputs (engine output torque and clutch transmitted torque) and two

The “Next Generation Train” (NGT) is a double-deck high speed train concept in light-weight design that has been established as a technical and project framework in which the German Aerospace Center gathers its long-term railway vehicle research. To reduce wheel and rail wear and to enhance the passenger capacity, a mechatronic running gear with independently rotating wheels (IRW) is a key vehicle

As the core of Industry 4.0, the intelligent manufacturing technology requires robotic arms to be networked, customized and flexible. Traditional industrial robots have a large number of electrical cables. The end effectors cannot be easily replaced. In this paper, a reconfigurable modular arm with quick replacement of tools and its neural adaptive control system are developed. It consists of an anthropomorphic

Virtual process planning offers advantages in terms of predicting servo and contouring errors ahead of time, and taking corrective action by modifying the program or CNC parameters. Successful application of virtual process planning requires accurate models that capture the dynamics of feed drives. Identification of such models is typically time consuming. This paper presents a pole search method used

Powered ankle-foot orthosis (PAFO) is a field of wearable robotics that improves the lives of people of old age or with physical impairments by aiding in the wearer's ankle joint movements. Most of the PAFOs developed thus far offer only one degree-of-freedom (dof), which uses the talocrural joint alone as the axis of rotation, where the emphasis is on moving forward. However, because this type of

In this study, the effects of contact forces on the rollers of a mecanum wheeled robot are investigated. Modeling structures are constructed for the cases of single and multiple contact forces. A simulation environment is developed to examine these two cases. A theoretical model is proposed in order to reflect reality in the simulation environment. It is shown that single contact force assumption generates

Collaborative tracking control involves two or more subsystems working together to perform a global objective, and is increasingly used within a diverse range of applications. Decentralised iterative learning control schemes have demonstrated highly accurate collaborative tracking by using past experience gained over repeated attempts at the task. However they impose highly restrictive constraints

Underactuated robotic systems have become an important research topic aiming at significant improvement of the behavioural performance and energy efficiency. Adopting some bio-inspired ideas and properties, the self-organisation and main tasks of the robotic systems can be achieved by coordination of the subsystems and dynamic interaction with the environment. Conversely, biological systems achieve

This work presents the design, simulation, control and experimental result of an optical scanning laser sensor for 3D imaging. The system design satisfies the Scheimpflug condition even though only the illumination path is scanned by a compact fast steering mirror (FSM). To reconstruct the surface profile from measured quantities and model parameters, geometrical relations are used. The influence of

In this paper, a new simple tracking control scheme is presented for quadrotor systems with uncertain dynamics. It precludes the necessity for prohibitive analytic computation of the derivatives of the desired (virtual) attitude that is typically employed in controlling quadrotor systems. Moreover, this control scheme is approximation-free in the sense that it does not incorporate any adaptive laws

This study presents an event driven automatic controller to regulate the movement of a mobile lower limb active orthosis (LLAO) triggered with the information obtained from electromyographic (EMG) signals, which are captured from the user’s triceps and biceps muscles. The proposed controller has an output feedback realization including a velocity estimator algorithm based on a high order sliding mode

Inversion-based feedforward control is a basic method of tracking controls. The aim of this paper is to design MIMO multirate feedforward controller that improves continuous-time tracking performance in MIMO LTI systems considering not only on-sample but also intersample behavior. Several types of MIMO multirate feedforward controllers are designed and evaluated in terms of the 2-norm of the control

The thermo-mechanical effects in machine tools (MTs) are represented by complex models since they may produce non-linear distortions overtime, impacting significantly on the machining accuracy. This paper aims to model the deformation of CFRP (Carbon-Fiber-Reinforced-Polymers) structures using data-driven schemes to predict and compensate the structural thermo-mechanical behavior. A novel study is

Thermally-induced disturbances limit the beam quality of high-power lasers and evoke set point-dependent disturbances. As a result, the beam parameters and the laser’s output power of conventional high-power lasers cannot be chosen independently. To overcome this issue, we suggest spherical intra-cavity mirrors as actuators to dynamically compensate the impact of thermal lensing within the framework

Frequency Response Functions (FRFs) are essential in mechatronic systems and its application ranges from system design and validation to controller design and diagnostics. The aim of this paper is to optimally design experiments for FRF identification of multivariable motion systems subject to element-wise power constraints. A multivariable excitation design framework is established that explicitly

Axial piston motors and pumps are core components in many hydromechanical systems as for instance the powertrain of wheel loader vehicles. The optimal performance of the individual components as well as the entire powertrain requires a fast and exact control of both the motor’s swivel angle as well as the pressure difference over the pump by means of the currently available information and despite