Development of Mathematical Models, Simulating Vibration Control of Tracked Vehicle Weapon Dynamics

2017 ◽  
Vol 67 (4) ◽  
pp. 465 ◽  
Author(s):  
Ambarish Jakati ◽  
Saayan Banerjee ◽  
C. Jebaraj

Focuses upon development of the mathematical model, simulating the tracked vehicle weapon dynamics, integrated over a half car platform. Governing differential equations have been formulated for the weapon system using state space approach, simulating the elevation dynamics over a half vehicle chassis, and coded using Matlab. The elevation model of the weapon comprises 3 degrees of freedom, arising from the rotational dynamics of the drive, breech and muzzle, which has sequentially been coupled to the half car model. Thereafter, the backstepping, LQR and PID control techniques have been derived and incorporated into the state space matrix for the coupled dynamics model, in which the control parameters have been arrived at through various iterations. Comparative weapon dynamics response studies have been carried out between that obtained from the above control strategies and the passive model, over standard terrain conditions at specified speeds. The above study would form a very useful framework for implementation of alternate control strategies for weapon stabilisation in the full tracked vehicle.

Author(s):  
Amir H. Danesh-Yazdi ◽  
Yi Wu ◽  
Oladipo Onipede

A consistent approach to solving problems in an undergraduate vibrations course in Mechanical Engineering is presented in this paper. The traditional approach of solving vibration problems involves several steps such as classifying the system according to degrees of freedom, free or forced vibrations and with or without damping. Based on the classification, an appropriate solution technique is applied and the results are obtained. Since the mathematical solution technique is strictly tied to the classification, students have to learn and apply a variety of solution methods based on the particular form of the mathematical model. The course was literally more like a math course rather than an engineering course. By introducing students to the state-space solution method early in the course and using it as the main/dominant solution method, students can focus more on learning both the physical modeling and mathematical modeling of the vibration systems as well as interpreting results in the engineering context. Since state-space computational solvers are readily available to students (MATLAB, Mathcad, etc.) and they can be applied to solve most (but not all) vibration problems including free or forced SDOF, 2DOF, MDOF systems with or without damping, it allows for consistency when teaching students how to solve vibration problems. State-space solvers can solve for either the time or the frequency response and provides a graphical solution. The students can go from modeling to visually exploring and interpreting results. The students’ response to this approach is also discussed.


Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1468
Author(s):  
Luis Nagua ◽  
Carlos Relaño ◽  
Concepción A. Monje ◽  
Carlos Balaguer

A soft joint has been designed and modeled to perform as a robotic joint with 2 Degrees of Freedom (DOF) (inclination and orientation). The joint actuation is based on a Cable-Driven Parallel Mechanism (CDPM). To study its performance in more detail, a test platform has been developed using components that can be manufactured in a 3D printer using a flexible polymer. The mathematical model of the kinematics of the soft joint is developed, which includes a blocking mechanism and the morphology workspace. The model is validated using Finite Element Analysis (FEA) (CAD software). Experimental tests are performed to validate the inverse kinematic model and to show the potential use of the prototype in robotic platforms such as manipulators and humanoid robots.


1995 ◽  
Vol 117 (3) ◽  
pp. 582-588 ◽  
Author(s):  
L. N. Virgin ◽  
T. F. Walsh ◽  
J. D. Knight

This paper describes the results of a study into the dynamic behavior of a magnetic bearing system. The research focuses attention on the influence of nonlinearities on the forced response of a two-degree-of-freedom rotating mass suspended by magnetic bearings and subject to rotating unbalance and feedback control. Geometric coupling between the degrees of freedom leads to a pair of nonlinear ordinary differential equations, which are then solved using both numerical simulation and approximate analytical techniques. The system exhibits a variety of interesting and somewhat unexpected phenomena including various amplitude driven bifurcational events, sensitivity to initial conditions, and the complete loss of stability associated with the escape from the potential well in which the system can be thought to be oscillating. An approximate criterion to avoid this last possibility is developed based on concepts of limiting the response of the system. The present paper may be considered as an extension to an earlier study by the same authors, which described the practical context of the work, free vibration, control aspects, and derivation of the mathematical model.


2020 ◽  
pp. 29-33
Author(s):  
S. V. Kondakov ◽  
O.O. Pavlovskaya ◽  
I.D. Ivanov ◽  
A.R. Ishbulatov

A method for controlling the curvilinear movement of a high-speed tracked vehicle in a skid without loss of stability is proposed. The mathematical model of the vehicle is refined. With the help of simulation modeling, a control algorithm is worked out when driving in a skid. The effectiveness of vehicle steering at high speed outside the skid is shown. Keywords: controlled skid, dynamic stability, steering pole displacement, hydrostatic transmission, automatic system, fuel supply. [email protected]


Author(s):  
Julián Andres Gómez Gómez ◽  
Camilo E. Moncada Guayazán ◽  
Sebastián Roa Prada ◽  
Hernando Gonzalez Acevedo

Abstract Gimbals are mechatronic systems well known for their use in the stabilization of cameras which are under the effect of sudden movements. Gimbals help keeping cameras at previously defined fixed orientations, so that the captured images have the highest quality. This paper focuses on the design of a Linear Quadratic Gaussian, LQG, controller, based on the physical modeling of a commercial Gimbal with two degrees of freedom (2DOF), which is used for first-person applications in unmanned aerial vehicle (UAV). This approach is proposed to make a more realistic representation of the system under study, since it guarantees high accuracy in the simulation of the dynamic response, as compared to the prediction of the mathematical model of the same system. The development of the model starts by sectioning the Gimbal into a series of interconnected links. Subsequently, a fixed reference system is assigned to each link body and the corresponding homogeneous transformation matrices are established, which will allow the calculation of the orientation of each link and the displacement of their centers of mass. Once the total kinetic and potential energy of the mechanical components are obtained, Lagrange’s method is utilized to establish the mathematical model of the mechanical structure of the Gimbal. The equations of motion of the system are then expressed in state space form, with two inputs, two outputs and four states, where the inputs are the torques produced by each one of the motors, the outputs are the orientation of the first two links, and the states are the aforementioned orientations along with their time derivatives. The state space model was implemented in MATLAB’s Simulink environment to compare its prediction of the transient response with the prediction obtained with the representation of the same system using MATLAB’s SimMechanics physical modelling interface. The mathematical model of each one of the three-phase Brushless DC motors is also expressed in state space form, where the three inputs of each motor model are the voltages of the corresponding motor phases, its two outputs are the angular position and angular velocity, and its four states are the currents in two of the phases, the orientation of the motor shaft and its rate of change. This model is experimentally validated by performing a switching sequence in both the simulation model and the physical system and observing that the transient response of the angular position of the motor shaft is in accordance with the theoretical model. The control system design process starts with the interconnection of the models of the mechanical components and the models of the Brushless DC Motor, using their corresponding state space representations. The resulting model features six inputs, two outputs and eight states. The inputs are the voltages in each phase of the two motors in the Gimbal, the outputs are the angular positions of the first two links, and the states are the currents in two of the phases for each motor and the orientations of the first two links, along with their corresponding time derivatives. An optimal LQG control system is designed using MATLAB’s dlqr and Kalman functions, which calculate the gains for the control system and the gains for the states estimated by the observer. The external excitation in each of the phases is carried out by pulse width modulation. Finally, the transient response of the overall system is evaluated for different reference points. The simulation results show very good agreement with the experimental measurements.


Author(s):  
Mounir Hammouche ◽  
Philippe Lutz ◽  
Micky Rakotondrabe

The problem of robust and optimal output feedback design for interval state-space systems is addressed in this paper. Indeed, an algorithm based on set inversion via interval analysis (SIVIA) combined with interval eigenvalues computation and eigenvalues clustering techniques is proposed to seek for a set of robust gains. This recursive SIVIA-based algorithm allows to approximate with subpaving the set solutions [K] that satisfy the inclusion of the eigenvalues of the closed-loop system in a desired region in the complex plane. Moreover, the LQ tracker design is employed to find from the set solutions [K] the optimal solution that minimizes the inputs/outputs energy and ensures the best behaviors of the closed-loop system. Finally, the effectiveness of the algorithm is illustrated by a real experimentation on a piezoelectric tube actuator.


2012 ◽  
Vol 630 ◽  
pp. 249-252
Author(s):  
An Cheng Chen ◽  
Xi Hui Mu ◽  
Feng Po Du

The necessity and importance of studying the dynamical characteristics of ramp steering was described. After the force analysis of ramping going up, down and along the slope, Especially don‘t ignored unchanged load distribution that was caused by the longitudinal force and lateral force, Establish the mathematical model of traction and braking force. Through the simulation experiment, the result showed that the traction and braking force changed with definite rules when the tracked vehicle turned on the slope, which has practical significance for the further study of the vehicle’s power matching problems.


Author(s):  
Reza Taghipour ◽  
Tristan Perez ◽  
Torgeir Moan

This article deals with time-domain hydroelastic analysis of a marine structure. The convolution terms in the mathematical model are replaced by their alternative state-space representations whose parameters are obtained by using the realization theory. The mathematical model is validated by comparison to experimental results of a very flexible barge. Two types of time-domain simulations are performed: dynamic response of the initially inert structure to incident regular waves and transient response of the structure after it is released from a displaced condition in still water. The accuracy and the efficiency of the simulations based on the state-space model representations are compared to those that integrate the convolutions.


2019 ◽  
Author(s):  
Ilya Kuzovkin ◽  
Konstantin Tretyakov ◽  
Andero Uusberg ◽  
Raul Vicente

AbstractObjectiveNumerous studies in the area of BCI are focused on the search for a better experimental paradigm – a set of mental actions that a user can evoke consistently and a machine can discriminate reliably. Examples of such mental activities are motor imagery, mental computations, etc. We propose a technique that instead allows the user to try different mental actions in the search for the ones that will work best.ApproachThe system is based on a modification of the self-organizing map (SOM) algorithm and enables interactive communication between the user and the learning system through a visualization of user’s mental state space. During the interaction with the system the user converges on the paradigm that is most efficient and intuitive for that particular user.Main resultsResults of the two experiments, one allowing muscular activity, another permitting mental activity only, demonstrate soundness of the proposed method and offer preliminary validation of the performance improvement over the traditional closed-loop feedback approach.SignificanceThe proposed method allows a user to visually explore their mental state space in real time, opening new opportunities for scientific inquiry. The application of this method to the area of brain-computer interfaces enables more efficient search for the mental states that will allow a user to reliably control a BCI system.


2021 ◽  
Vol 11 (23) ◽  
pp. 11095
Author(s):  
Antonio P. L. Bo ◽  
Leslie Casas ◽  
Gonzalo Cucho-Padin ◽  
Mitsuhiro Hayashibe ◽  
Dante Elias

Among end-effector robots for lower limb rehabilitation, systems based on Stewart–Gough platforms enable independent movement of each foot in six degrees of freedom. Nevertheless, control strategies described in recent literature have not been able to fully explore the potential of such a mechatronic system. In this work, we propose two novel approaches for controlling a gait simulator based on Stewart–Gough platforms. The first strategy provides the therapist direct control of each platform using movement data measured by wearable sensors. The following scheme is designed to improve the level of engagement of the patient by enabling a limited degree of control based on trunk inclination. Both strategies are designed to facilitate future studies in tele-rehabilitation settings. Experimental results have illustrated the feasibility of both control interfaces, either in terms of system performance or user subjective evaluation. Technical capacity to deploy in tele-rehabilitation was also verified in this work.


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