Dynamic parameters identification of a haptic interface for a helicopter flight simulator

Abstract. The haptic interface force feedback is one of the key factors for a reliable flight simulation. This paper addresses the design and control implementation of a simple joystick-like haptic interface to be used for a helicopter flight simulator. The expression of the haptic interface force is obtained by dynamic analysis of the haptic interface operation. This paper proposes a new strategy aiming at avoiding the use of an expansive and complex force/torque sensor. Accordingly, specific dynamic model is implemented by including Stribeck friction to describe the friction moment. Experimental data are processed as based on a genetic algorithm for identifying the dynamic parameters in the Stribeck friction model. This allows to obtain the friction moment parameters of the haptic interface, as well as the torque distribution due to gravity and the rotational inertia parameters of the haptic interface for the calculation of the haptic interface force. Experimental tests are carried out and results are used to validate the proposed dynamic model and dynamic parameter identification method and demonstrate the effectiveness of the proposed force feedback while using a cheap photoelectric sensor instead of an expansive force/torque sensor

Neural Induction Potential and MRI of ADSCs Labeled Cationic Superparamagnetic Iron Oxide Nanoparticle In Vitro

Magnetic resonance imaging (MRI) combined with contrast agents is believed to be useful for stem cell tracking in vivo, and the aim of this research was to investigate the biosafety and neural induction of SD rat-originated adipose derived stem cells (ADSCs) using cationic superparamagnetic iron oxide (SPIO) nanoparticle which was synthesized by the improved polyol method, in order to allow visualization using in vitro MRI. The scan protocols were performed with T2-mapping sequence; meanwhile, the ultrastructure of labeled cells was observed by transmission electron microscopy (TEM) while the iron content was measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). After neural induction, nestin and NSE (neural markers) were obviously expressed. In vitro MRI showed that the cationic PEG/PEI-modified SPIO nanoparticles could achieve great relaxation performance and favourable longevity. And the ICP-AES quantified the lowest iron content that could be detected by MRI as 1.56~1.8 pg/cell. This study showed that the cationic SPIO could be directly used to label ADSCs, which could then inductively differentiate into nerve and be imaged by in vitro MRI, which would exhibit important guiding significance for the further in vivo MRI towards animal models with neurodegenerative disorders

Energy Consumption Analysis of Helicopter Traction Device: A Modeling Method Considering Both Dynamic and Energy Consumption Characteristics of Mechanical Systems

Since modern times, the increase in shipborne equipment has brought tremendous pressure to the energy supply system. Establishing an accurate and reliable energy consumption model that reflects the dynamic characteristics of the system will provide an essential theoretical reference for energy efficiency optimization. This paper proposes a modeling method that considers both the dynamic characteristics and energy consumption characteristics of the system, based on the power bond-graph theory. Firstly, the transmission principle and energy transfer process of hydraulic and electric helicopter traction devices are analyzed. Then, the energy consumption is analyzed, and the state equation and energy equation of the system are established. Finally, the simulation tests are carried out. The results show that the proposed dynamic modeling method is reasonable and effective and can well reflect the dynamic characteristics and energy consumption characteristics of the system

Electrical Aircraft Ship Integrated Secure and Traverse System Design and Key Characteristics Analysis

The shipborne helicopter is an essential maritime combat force of the modern navy. However, as the most advanced shipborne helicopter landing assistance system, the ASIST still suffers from the significant disadvantage of the uncontrollable driving speed of the claw. This paper aims to propose an implementation scheme of the EASIST transmission system by selecting an asynchronous motor as the direct power source to solve the problem. On this basis, the speed controller is built by combining the vector control algorithm with an ANFIS control algorithm. In addition, the capture and traction characteristics of EASIST are analyzed, and the capture track of the claw and the maximum load in the traction process are obtained. Finally, the dynamics model of the transmission system is established by power bond graph theory, and the system simulation test is carried out. Simulation results show that the proposed EASIST reduces the capture time by about 60% and dramatically reduces the capture speed. And when towing the shipborne helicopter, EASIST can keep a good speed-tracking effect under the action of wildly varying load force. The research results of this paper are of great significance to broaden the application scope of ASIST and improve the traction efficiency, which plays a vital role in enhancing the combat effectiveness of shipborne helicopters

Design and Motion Characteristics of Active–Passive Composite Suspension Actuator

The suspension system needs both an active mode and passive mode when the emergency rescue vehicle is running on a complex road. Therefore, an active–passive composite suspension actuator (APCSA) is designed in this paper. Firstly, combined with computational fluid dynamics theory and dynamic mesh technology, the complete fluid domain of the original passive suspension actuator (PSA) is simulated. Secondly, in accordance with the simulation results and in consideration of the working conditions of the active suspension of the emergency rescue vehicle, the APCSA is designed, and its flow field characteristics are studied. Finally, test results show that the maximum recovery damping force/compression damping force of the APCSA is 2428.98 N/−1470.29 N, which is 53.5%/50.4% lower than that of the original PSA. Hence, the dynamic response capability of the actuator is effectively improved, which lays a foundation for improving the ride comfort and handling stability of emergency rescue vehicles on complex roads

Research on Shipborne Helicopter Electric Rapid Secure Device: System Design, Modeling, and Simulation

The research objective of this paper is to propose a new type of ERSD to solve the problem of the uncontrollable velocity of the claw in the current RSD. Firstly, the working characteristics of the RSD in ASIST are analyzed, and the design scheme of the transmission system of the ERSD is provided. The control system is designed by combining the vector control algorithm with the fuzzy adaptive PID control algorithm. On this basis, the trajectory planning of claw capture velocity is completed. Finally, the dynamics model of the transmission system of the ERSD is built by power bond graph theory, and the system simulation is carried out. The results show that the maximum capture time, velocity, and force were reduced by 47%, 53%, and 80%. In addition, when the ERSD is towing the helicopter, the mechanical claw can still provide good velocity tracking performance under a maximum interference load of 34,000 N