scholarly journals Control of an Omnidirectional UAV for Transportation and Manipulation Tasks

2021 ◽  
Vol 11 (22) ◽  
pp. 10991
Author(s):  
Michelangelo Nigro ◽  
Francesco Pierri ◽  
Fabrizio Caccavale
Keyword(s):  
Motion Control ◽  
Mechanical Design ◽  
Contact Forces ◽  
Motion Controller ◽  
Joint Torques ◽  
External Loop ◽  
Control Scheme ◽  
Aerial Vehicle ◽  
The Stability ◽  
The Moment

This paper presents a motion control scheme for a new concept of omnidirectional aerial vehicle for transportation and manipulation tasks. The considered aerial platform is a novel quadrotor with the capability of providing multi-directional thrust by adding an actuated gimbal mechanism in charge of modifying the orientation of the frame on which the four rotors are mounted. The above mechanical design, differently from other omnidirectional unmanned aerial vehicles (UAVs) with tilted propellers, avoids internal forces and energy dissipation due to non-parallel propellers’ axes. The proposed motion controller is based on a hierarchical two-loop scheme. The external loop computes the force to be applied to the vehicle and the reference values for the additional joints, while the inner loop computes the joint torques and the moment to be applied to the multirotor. In order to make the system robust with respect to the external loads, a compensation of contact forces is introduced by exploiting the estimate provided by a momentum based observer. The stability of the motion control scheme is proven via Lyapunov arguments. Finally, two simulation case studies prove the capability of the omnidirectional UAV platform to track a 6-DoFs trajectory both in free motion and during a task involving grasping and transportation of an unknown object.

Digital Motion Control and Profile Planning for Pneumatic Servos

1992 ◽  
Vol 114 (4) ◽  
pp. 634-640 ◽  
Author(s):  
J. Pu ◽  
R. H. Weston ◽  
P. R. Moore
Keyword(s):  
Motion Control ◽  
Transient Behavior ◽  
Performance Characteristics ◽  
Motion Controller ◽  
Operating Characteristics ◽  
Servo Systems ◽  
Pneumatic Actuators ◽  
Control Scheme ◽  
Conventional Methods ◽  
The Stability

This paper considers the use of “profile-planning” to (i) improve/optimize certain performance characteristics of pneumatic servos and (ii) simplify procedures associated with their tuning. The underlying approach is to preplan the transient behavior of the system thereby generating an appropriate command profile. To assist in applying this technique to the control of air-powered servo-systems, the paper highlights important knowledge derived previously with regard to the stability and operating characteristics of pneumatic drives. Preliminary rules for conducting such planning are then proposed with reference to a series of experimental observations. This approach can be employed to significantly reduce or prevent overshoot and instability of servo-driven pneumatic actuators (cylinders in particular) which are difficult to overcome by using conventional methods. At the same time, increased operating speeds and improved positioning can be attained. The proposed control scheme has been implemented in prototype form through using a proprietary programmable motion controller which incorporates software mechanism for generating gearbox and cam-like motion profiles.

scholarly journals An adaptive hierarchical control for aerial manipulators

Robotica ◽  
2018 ◽  
Vol 36 (10) ◽  
pp. 1527-1550 ◽  
Author(s):  
Francesco Pierri ◽  
Giuseppe Muscio ◽  
Fabrizio Caccavale
Keyword(s):  
Control Algorithm ◽  
Hierarchical Control ◽  
Bottom Layer ◽  
Trajectory Tracking Control ◽  
Aerial Manipulator ◽  
Control Scheme ◽  
Modelling Uncertainties ◽  
Aerial Vehicle ◽  
The Stability

SUMMARYThis paper addresses the trajectory tracking control problem for a quadrotor aerial vehicle, equipped with a robotic manipulator (aerial manipulator). The controller is organized in two layers: in the top layer, an inverse kinematics algorithm computes the motion references for the actuated variables; in the bottom layer, a motion control algorithm is in charge of tracking the motion references computed by the upper layer. To the purpose, a model-based control scheme is adopted, where modelling uncertainties are compensated through an adaptive term. The stability of the proposed scheme is proven by resorting to Lyapunov arguments. Finally, a simulation case study is proposed to prove the effectiveness of the approach.

Opto-electronic platform tracking control of multi-rotor unmanned aerial vehicles based on composite disturbance compensation

2019 ◽  
Vol 233 (12) ◽  
pp. 4410-4420 ◽  
Author(s):  
Rijun Wang ◽  
Yue Bai ◽  
Zhiqiang Zeng ◽  
Junyuan Wang ◽  
Wenhua Du ◽  
...  
Keyword(s):  
Disturbance Observer ◽  
Adaptive Fuzzy Control ◽  
Tracking Performance ◽  
Velocity Signal ◽  
Control Precision ◽  
Control Scheme ◽  
Vehicle Systems ◽  
Aerial Vehicle ◽  
Series Of Experiments ◽  
The Stability

Airborne opto-electronic platforms are very important in unmanned aerial vehicle systems. The stability and tracking performance of airborne opto-electronic platforms are easily affected by disturbance factors, making compensating for those disturbances a very prominent issue. In this paper, compared to the traditional disturbance observer, an improved velocity signal based disturbance observer (IVDOB) is particularly designed to compensate for the disturbance. Then its capability, robustness, and stability are discussed. For improving the stabilization accuracy and tracking performance of airborne opto-electronic platforms, the universal approximation property of fuzzy systems is used to compensate the disturbance further and an adaptive fuzzy control system based on IVDOBs is proposed. To validate the scheme, a series of experiments were carried out. The results show that the proposed control scheme can achieve reliable control precision and satisfy the requirements of airborne opto-electronic platform tasks.

scholarly journals Disturbance Rejection Attitude Control for a Quadrotor: Theory and Experiment

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Li Ding ◽  
Qing He ◽  
Chengjun Wang ◽  
Rongzhi Qi
Keyword(s):  
Attitude Control ◽  
Disturbance Rejection ◽  
Sliding Mode ◽  
External Disturbances ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Aerial Vehicle ◽  
Linear Extended State Observer ◽  
The Stability ◽  
Theory And Experiment

In this article, an attitude tracking controller is designed for a quadrotor unmanned aerial vehicle (UAV) subject to lumped disturbances. Firstly, the attitude dynamical model of the quadrotor under external disturbances is established. Subsequently, an improved sliding mode control (SMC) strategy is designed based on the linear extended state observer (LESO). In this control scheme, the SMC will guarantee the sliding surface is finite time reachable and the LESO will estimate and compensate for the lumped disturbances. Then, the robustness and asymptotic stability of the proposed controller are proved by the stability analyses. Finally, three numerical simulation cases and comparative flight experiments validate the effectiveness of the developed controller.

Towards the Design of a Fully Actuated Invertible Flying Quadrotor MAV

2013 ◽  
Author(s):  
Andreas Gelardos ◽  
David J. Cappelleri
Keyword(s):  
Closed Loop ◽  
Mechanical Design ◽  
Low Cost ◽  
Open Loop ◽  
Transmission Mechanism ◽  
Micro Aerial Vehicle ◽  
Loop Control ◽  
Minimal Weight ◽  
Control Scheme ◽  
Aerial Vehicle

In this paper, we present the transmission mechanism design for a fully actuated Invertible Flying Quadrotor (IFQ) micro aerial vehicle (MAV). At the heart of the mechanism is a gearbox which couples and counter rotates two pairs of shafts that have the quadrotor propellers mounted at their ends. This mechanism will allow for the IFQ to follow aggressive maneuvers, hover at an arbitrary attitude, and have sustained inverted flight capabilities. The paper presents the mechanical design challenges and solutions in designing such a transmission mechanism with minimal weight along with low cost and easy manufacturing. The dynamic model for the IFQ MAV is presented along with an optimal open loop trajectory control scheme and related simulations. An approach for a full closed loop control scheme is also discussed. A prototype of the mechanism has been manufactured and functionally tested. The entire transmission mechanism was able to be prototyped with a weight of only approximately 100 grams.

Wingbeat Generation for a 15 DOF Flexible-Wing Aerial Vehicle Using Cosine Wave Functions

2017 ◽  
Vol 05 (02) ◽  
pp. 115-127
Author(s):  
Willson Amalraj Arokiasami ◽  
Prahlad Vadakkepat ◽  
Abdullah Al Mamun
Keyword(s):  
Mechanical Design ◽  
Cost Effective ◽  
Wave Functions ◽  
Dynamics Simulation ◽  
Forward Dynamics ◽  
Aerodynamic Forces ◽  
Joint Torques ◽  
Flexible Wing ◽  
Wind Gusts ◽  
Aerial Vehicle

Birds and conventional airplanes control their flight in a different manner. Conventional airplanes maneuver themselves by means of moving surfaces, while birds can bend, twist and deform their wings and adapt to unforeseen conditions such as wind gusts. However, if planes can do exactly as the birds do they can gain agility, more lift, less drag while consuming less fuel. This work aims to address this issue. Therefore, approaches of wingbeat generation for a 15 DOF flexible-wing aerial vehicle are developed in this paper. A computationally cost-effective cosine wave function-based algorithm that computes a set of wingbeats enabling the aerial vehicle to follow a desired trajectory in a realistic manner is discussed. The flexible-wing aerial vehicle is modeled similar to a seagull with an articulated skeleton. Motion of the aerial vehicle is simulated by applying joint torques and aerodynamic forces over a period of time in forward dynamics simulation. Wing and tail feather motions generate lift in the aerial vehicle, which makes it possible for the aerial vehicle to trace predefined paths. The solidworks mechanical design is used as input into Matlab SimMechanics for visualization. The results are promising for the construction of bird-like aerial vehicles.

scholarly journals A Novel Adaptive Super-Twisting Sliding Mode Control Scheme with Time-Delay Estimation for a Single Ducted-Fan Unmanned Aerial Vehicle

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 54
Author(s):  
Minh-Thien Tran ◽  
Dong-Hun Lee ◽  
Soumayya Chakir ◽  
Young-Bok Kim
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Unmanned Aerial Vehicle ◽  
Sliding Mode ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Mode Control ◽  
Ducted Fan ◽  
Control Scheme ◽  
Aerial Vehicle

This article proposes a novel adaptive super-twisting sliding mode control scheme with a time-delay estimation technique (ASTSMC-TDE) to control the yaw angle of a single ducted-fan unmanned aerial vehicle system. Such systems are highly nonlinear; hence, the proposed control scheme is a combination of several control schemes; super-twisting sliding mode, TDE technique to estimate the nonlinear factors of the system, and an adaptive sliding mode. The tracking error of the ASTSMC-TDE is guaranteed to be uniformly ultimately bounded using Lyapunov stability theory. Moreover, to enhance the versatility and the practical feasibility of the proposed control scheme, a comparison study between the proposed controller and a proportional-integral-derivative controller (PID) is conducted. The comparison is achieved through two different scenarios: a normal mode and an abnormal mode. Simulation and experimental tests are carried out to provide an in-depth investigation of the performance of the proposed ASTSMC-TDE control system.

Joint Mechanical Design and Flight Control Optimization of a Nature-Inspired Unmanned Aerial Vehicle via Collaborative Co-Evolution

2021 ◽  
Vol 6 (2) ◽  
pp. 2044-2051
Author(s):  
Danial Sufiyan ◽  
Luke Soe Thura Win ◽  
Shane Kyi Hla Win ◽  
Gim Song Soh ◽  
Shaohui Foong
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Flight Control ◽  
Mechanical Design ◽  
Control Optimization ◽  
Aerial Vehicle

scholarly journals Terrain classification and adaptive locomotion for a hexapod robot Qingzhui

2021 ◽  
Author(s):  
Yue Zhao ◽  
Feng Gao ◽  
Qiao Sun ◽  
Yunpeng Yin
Keyword(s):  
Legged Robots ◽  
Measurement Unit ◽  
Support Vector ◽  
Hexapod Robot ◽  
Terrain Classification ◽  
Adaptive Locomotion ◽  
Joint Torques ◽  
Active Compliance ◽  
Outdoor Environments ◽  
The Stability

AbstractLegged robots have potential advantages in mobility compared with wheeled robots in outdoor environments. The knowledge of various ground properties and adaptive locomotion based on different surface materials plays an important role in improving the stability of legged robots. A terrain classification and adaptive locomotion method for a hexapod robot named Qingzhui is proposed in this paper. First, a force-based terrain classification method is suggested. Ground contact force is calculated by collecting joint torques and inertial measurement unit information. Ground substrates are classified with the feature vector extracted from the collected data using the support vector machine algorithm. Then, an adaptive locomotion on different ground properties is proposed. The dynamic alternating tripod trotting gait is developed to control the robot, and the parameters of active compliance control change with the terrain. Finally, the method is integrated on a hexapod robot and tested by real experiments. Our method is shown effective for the hexapod robot to walk on concrete, wood, grass, and foam. The strategies and experimental results can be a valuable reference for other legged robots applied in outdoor environments.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

2021 ◽  
pp. 095441002110136
Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Computationally Efficient ◽  
Control Scheme ◽  
Control Schemes ◽  
Adaptive Laws ◽  
Unknown Disturbances ◽  
The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

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