Search results

A system has been devised for the fast assembly of pegs in holes using a guiding frame which has four degress of freedom and which is separated from the insertion actuator.

The purpose of this study is to define configuration requirements needed to define “harmless” small unmanned aerial systems (sUAS) by taking into account mathematical models and ballistic approaches, already defined for small projectiles and now modified, with appropriate assumptions. These safety requirements are related to structures, materials, weight and dimensions, such as the radius of curvature.

In this paper, the state-of-the-art forensic and ballistic physics models are presented, and then safety requirements are defined for sUAS. This big challenge is due to a lack of regulation because each country and each regulatory authority have published their own regulations, where the imposed requirements are different because the mathematical models, and the related assumptions, are different from one country to another. Therefore, proper assumptions are introduced in these models to obtain safety requirements to define harmless final configuration.

If the final configuration meets the requirements defined in the methodology, there are no severe injuries on the human body, in case of impact with the sUAS. In other words, the inoffensive configuration can also be used in overcrowded areas without risks for the human life.

The final configuration proposed in this paper has some design features substantially modified, compared to the conventional configuration, and in particular, the sUAS could be the first harmless multicopter certified in Italy.

A pneumatic‐fluidic system has been designed and built, with the purpose to recognize the side orientation of pieces.

The purpose of this paper is to present an original design procedure for a flight control system.

An optimization process, based on a genetic algorithm (GA), is used to meet the frequency domain handling qualities requirements in the longitudinal plane for an unconventional platform characterized by nonlinear aerodynamics. The parameters are implemented in the search process as fitness functions related to the expected magnitude of bandwidth and delay for an existing micro aerial vehicle. The bandwidth and the delay of the longitudinal short‐term attitude response are estimated before and after the inclusion of the flight control system in the simulation model, and the parameters are compared with the expected handling qualities levels. A qualitative analysis of handling qualities levels is also performed by implementing the augmented aircraft in a simulator with a realistic visual environment.

The results show that an optimal search process based on a GA can implement the handling qualities requirements with a computational procedure that is straightforward.

Even if the requisites for bandwidth and delay implemented in the search process are general in use as no specific aircraft response type is taken as a reference for the estimation of handling qualities requirements, only future experimental work will provide insight for the definition of specific Level 1 boundaries for micro aerial vehicles in remotely piloted flight.

The virtual environment is useful to test remote piloting with unconventional onboard visual cues. This is important in applications in which technical limitations may preclude complete real time data link during flight tests in the first development phase of the vehicle.

The purpose of this paper is to report the research activity of Politecnico di Torino concerning the MicroHawk platform (micro‐aerial vehicles – MAVs) and to present the design and the development of a basic flight simulator for educational/training purpose.

A simulator is an easy‐to‐use system for the analysis of maneuver response, the dynamic study and the evaluation of the aircraft flying and handling qualities for different aircraft categories. The software implementation, including the definition of mathematical model, the visual scenario and the real‐time data analysis graphic interface, are delineated in this paper. In addition to this experimental phase, an important effort is done to incorporate simulation into the autopilot tuning process.

An intense flight activity is carried out to test the flight control system performances of the MicroHawk platform and to establish general procedures to ensure the correct operation of all subsystems. The automatic flight of MAVs has been studied with success for territorial surveillance and map project.

In order to simplify the use of these platforms by the end‐user, a software interface will be designed to calculate automatically the flight plan, ensuring the desired trajectory design and collision avoidance.

The autopilot simulation integrated with vehicle's dynamics can be used to reduce the platform set‐up time and the risk of losing the prototype. The simulator training permits to study flight complex plane, in order to obtain better platform performances in real conditions. Starting from a simple scenario, it is possible to set up and upgrade the mission at any time during the simulation.

The aim of this paper is the implementation and validation of control and guidance algorithms for unmanned aerial vehicle (UAV) autopilots.

The path-following control of the UAV can be separated into different layers: inner loop for pitch and roll attitude control, outer loop on heading, altitude and airspeed control for the waypoints tracking and waypoint navigation. Two control laws are defined: one based on proportional integrative derivative (PID) controllers both for inner and outer loops and one based on the combination of PIDs and an adaptive controller.

Good results can be obtained in terms of trajectory tracking (based on waypoints) and of parameter variations. The adaptive control law guarantees smoothing responses and less oscillations and glitches on the control deflections.

The proposed controllers are easily implementable on-board and are computationally efficient.

The algorithm validation via hardware in the loop simulations can be used to reduce the platform set-up time and the risk of losing the prototype during the flight tests.

The growing use of small unmanned rotorcraft in civilian applications means that safe operation is increasingly important. The purpose of this paper is to investigate the fault tolerant properties to faults in the actuators of an C ₁ adaptive controller for a quadrotor vehicle.

C ₁ adaptive control provides fast adaptation along with decoupling between adaptation and robustness. This makes the approach a suitable candidate for fault tolerant control of quadrotor and other multirotor vehicles. In the paper, the design of an C ₁ adaptive controller is presented. The controller is compared to a fixed-gain LQR controller.

The C ₁ adaptive controller is shown to have improved performance when subject to actuator faults, and a higher range of actuator fault tolerance.

The control scheme is tested in simulation of a simple model that ignores aerodynamic and gyroscopic effects. Hence for further work, testing with a more complete model is recommended followed by implementation on an actual platform and flight test. The effect of sensor noise should also be considered along with investigation into the influence of wind disturbances and tolerance to sensor failures. Furthermore, quadrotors cannot tolerate total failure of a rotor without loss of control of one of the degrees of freedom, this aspect requires further investigation.

Applying the C ₁ adaptive controller to a hexrotor or octorotor would increase the reliability of such vehicles without recourse to methods that require fault detection schemes and control reallocation as well as providing tolerance to a total loss of a rotor.

In order for quadrotors and other similar unmanned air vehicles to undertake many proposed roles, a high level of safety is required. Hence the controllers should be fault tolerant.

Fault tolerance to partial actuator/effector faults is demonstrated using an C ₁ adaptive controller.

This paper aims to realize the automatic assembly process for multiple rigid peg-in-hole components.

This paper develops fuzzy force control strategies for the rigid dual peg-in-hole assembly. Firstly the fuzzy force control strategies are presented. Secondly the contact states and contact forces are analyzed to prove the availability of the force control strategies.

The rigid dual peg-in-hole assembly experimental results show the effectiveness of the control strategies.

This paper proposes fuzzy force control strategies for a rigid dual peg-in-hole assembly task.

The purpose of this paper is to develop, extend and propose an improved proportional integral derivative (PID) rate control of a quadrotor unmanned aerial vehicle based on a convexity-based surrogated firefly algorithm.

An improved PID controller structure is proposed for the rate dynamics of the quadrotor. Optimality of the controller is ensured by a recent, simple yet efficient firefly optimization method. The hybrid structure is further enhanced with a convexity-based surrogated model function.

Monte Carlo, transient response, error metrics and histogram distribution analyzes are conducted to show the performance of the proposed controller. The performance of the proposed method is evaluated under various convex combination values to further investigate the effect of the proposed surrogated model. According to the results, the proposed method is capable of controlling the rate quadrotor dynamics with the steady-state error of 0.0023 (rad/s) for P, −0.0024 (rad/s) for Q and 0 (rad/s) for the R state, respectively. Also, the least mean objective value is achieved at = 0 value of convexity in Monte Carlo trials.

The originality of this paper is to propose an improved PID rate controller with a convexity-based surrogated firefly algorithm.