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Gearbox is an indispensable element allied with mechanical industries to fluctuate speed and load in accordance with the requirements. More improvements in its mechanical structure and procedure can increase the efficiency of the industries. For those reasons, the gearbox was designed and manufactured very carefully with the zero tolerance of defects. Gearbox failure can lead to an increase in financial loss and decrease in production strength. Vibration signal analysis is used to monitor the gearbox condition. But, non-stationary properties of vibration signal make this procedure very challenging. Therefore, this paper presents a unique gearbox fault investigation technique based on advanced computational intelligence. Firstly, Time Synchronous Averaging algorithm was used to study the nonstationary properties of the raw vibration signal. Then, nine types of time domain arithmetical features were calculated from the pre-processed TSA vibration signal. After that, the J48 algorithm was used for significant features selection of gearbox fault and Naive Bayes algorithm for features classification of gearbox fault. A computer-aided fault simulator was used for experimental study. MATLAB and WEKA platforms were used for signal processing, features selection, and features classification of the gearbox faults. The performance of the proposed method shows meaningful results for gearbox fault diagnosis.

The hybrid manipulators are always found to be of great use in industries due to the major shortcoming of serial manipulators (lesser accuracy and heavy structure) and parallel manipulators (small workspace). Henceforth, a three-dimensional hybrid manipulator is presented in this paper and this hybrid manipulator connects two parallel manipulators in a serial arrangement. Afterwards, the theory of impedance control with some changes is applied for an operation on a three dimensional L-shaped path having some restrictions imposed on the interactive forces when the manipulator is interacting with an object in its environment along with an approach to eliminate amnesia i.e. difference between the actual trajectory and the command trajectory. The overwhelming controller is used between the actual system and the inverse controller. It is observed from the result that there is always some amnesia during force control and some time is provided before the next phase of force control to remove this difference in trajectory.

Time synchronous averaging (TSA) has been extensively applied for gearbox fault analysis. But it cannot unveil the vibration features precisely in conditions of different speeds and load excitation. This paper presents an improved method which is a combination of Time synchronous averaging (TSA) and Empirical mode decomposition (EMD) to extract the intermittent vibration feature from the oscillated vibration response for the fault diagnosis of the gearbox. In this technique, time-synchronous averaging and empirical mode decomposition is performed on the gearbox vibration response to detect fault features. First, TSA is performed on the gearbox raw vibration response. By applying TSA on raw vibration response, a noiseless vibration response with the power spectrum is produced. Finally, decomposition technique is applied on noiseless vibration response and a sequence of IMFs are produced with the power spectrum to obtain more enhanced and improved mono-component of noiseless regular vibration response. Simulation and Practical investigation of the proposed method show the advantages and effectiveness in extracting faulty vibration feature with different speed and load excitation. An experimental investigation has been carried out on the Machinery Fault Simulator with one healthy and two faulty gearbox conditions i.e., healthy tooth, fragmented tooth and missing tooth under three different speed and load excitation.

The walking mobile robots have several advantages as compared to the wheel mobile robots over uneven terrains. The researchers have done a lot to develop different walking mechanisms for legged robots. Due to merits of legged robots such as scalable design, low payload-to-machine load ratio, bio-inspired locomotion, etc., the researchers have shown a great interest in the walking robots based on the Theo Jansen mechanism. In this paper, the dynamic analysis of a four-legged quadruped robot-based upon Jansen mechanism is proposed. The SimMechanics Toolbox Mathworks software is used for developing the physical modeling of the quadruped robot. Also, the real quadruped robot based on Jansen mechanism is developed and validated with a simulation model for checking the trajectory tracking performance. The proposed model of the quadruped robot is used for the application of obstacle avoidance. The fuzzy logic controller is proposed to detect and avoid the obstacles by the robots. Three Ultrasonic sensors (HC-SR04) are mounted in front of the robot to detect the obstacles. The validation of simulation and experimental results shows the performances of the navigation and obstacle avoidance fuzzy controller.

In construction industry, the conventional way of construction of buildings is a costly, time consuming and a labour-intensive job. Besides that, many on-site fatalities happen during the construction activity and the climate can delay construction activity. 3-D printer robot resolves all these problems. Also, it can be used for intricate building designs and for construction of buildings in remote locations or in epidemic situations. The objective of the project is to make an autonomous robot for 3-D printing a simple civil structure. Three lead screws will provide the movement in the vertical as well as in horizontal directions and a nozzle connected to the horizontal lead screw will be used for pouring the construction-material layer by layer. Thereafter, structural analysis using Finite Element Method (FEM) has been done on critical parts like lead screw and top plate. Bond graphs for buggy and overall lead screw system have also been used to analyze the response of the system. Furthermore, the wring diagram is also developed and presented in the paper. Future research is required for the development of actual robot for building multi-storied structures, on the design of nozzle and type of material used for pouring.

A personal transporter vehicle, called segway, is based on the stabilization principle of inverted pendulum system. In this work, the bond graph model of segway with PI control is developed. The simulation results for the forward and backward motion of segway are presented as pitch angle, speed of the vehicle with respect to time. For the turning of the vehicle, controller based on Ackermann steering mechanism is adopted to modulate the voltages of two motors. The results of turning motion of the segway are also presented as yaw angle response of main vehicle body. The focus of this paper is to develop the dynamic model and simulate the response of segway using non-model-based control system design. The objective of the work is accomplished by developing the stabilization controller based on PI control scheme using bond graph approach. Also, the swing up controller is developed for nonlinear behaviour of the segway.

Nowadays, the key research area of many researchers is the walking mechanism of the robot as walking robots are used in many areas such as military, exploring new materials in space etc. The legged robots are much more capable to move on any type of terrain as compared to wheel robots. The focus of this work is to modelling, simulation and control a stable walking system for quadruped robot model. The proposed model of the quadruped robot is validated for side ramp walking without falling down due its weight. The PI controller is developed to control the movement of the quadruped during walking on the side ramp, which is not reported in literature. Initially, modelling of quadruped robot is done using bond graph approach and Simmechanics technique. Results from both methods are compared and discussed. The trot gait is considered for stable walking of quadruped robot. The Proportional-Integral (PI) based control scheme is proposed for locomotion of the robot along desired path. Finally, the case study for validation of proposed model is done for side ramp walking of quadruped robot.

The dynamics of the four-cylinder In-line engine is taken into account in this work. Firstly, the motion and thermodynamics equations of the engine model are discussed. The bond graph model of the four-cylinder in-line engine with 1-3-4-2 firing order is developed by using SYMBOLS Shakthi software. The thermodynamic and mechanical phenomena are considered while developing the model of the engine. The various engine characteristics parameters such as crank speed vs. torque developed, speed and acceleration of the crank for different values of J (mass moment of inertia of flywheel), piston stroke length of all cylinders and pressure-volume diagram, etc., are discussed for proposed model of the engine. Also, the piston–cylinder model based on prismatic joint is discussed and its bond graph model is developed.

Legged robots have capability of traversing on any type of terrain with much ease and stability compared to wheeled robots. The legged robots do not have continuous contact with ground, and thus, it is easy to avoid obstacles. The objective of this paper is to model and simulate a walking mechanism for quadruple model that is stable and is able to implement different types of gaits. The stability control of legged robot is of utmost importance as compared to wheeled robot as contact from ground is discontinuous due to lifting and placing of leg. The positing of legs relative to body of robot considerably affects the stability, and also the sequence and timing in which legs are moved and placed play important role in energy efficiency. Here, model of quadruped robot with four legs has been developed using bond graph technique. Results from simulation are discussed. The comparison of different gaits is made for energy efficiency.

This paper deals with the fault detection, isolation (FDI) and reconfiguration of the locomotion of a bipedal-legged robot. Initially, the planar model of the legged robot in the vertical plane is developed using a bond graph (BG) approach. Then, the planar BG model of the legged robot is extended to the three-dimensional legged robot. Two individual motors are used to actuate the prismatic leg of the robot for locomotion. The BG simulation provides results for straight walking based on an oscillating cylinder mechanism and the turning motion of the legged robot are discussed. The prototype model of the legged robot is also developed and experimentation is done for straight and inclined plane applications. Finally, an FDI technique for the three-dimensional model of a legged robot is developed for the generation of fault indicators (i.e., analytical redundancy relations; ARRs) in the presence of system failure. The ARRs are derived from the BG model of the legged robot during the occurrences of the fault. The experimental results are validated with the simulation results for FDI and reconfiguration when the robot manoeuvres in a U-shaped path. The real-time fault diagnosis and reconfiguration for locomotion of the legged robot is possible with this FDI approach.

Generally, industrial manipulators have parallel architecture but these are not generally used because of small workspace as compared to serial manipulators. The drawbacks of serial manipulators are their low accuracy and less load carrying capacity. Therefore, hybrid manipulators are considered to be useful because they are combination of serial and parallel manipulators. In this paper, a three-dimensional hybrid manipulator with two parallel manipulators serially connected to each other is proposed. The forward and inverse dynamics of the system is modelled with the help of bond graph. Thumb and index finger of a human right hand are considered as hybrid manipulators in this paper. The objective of present work is to track the trajectory by thumb in three-dimensional space while drawing an arc on a white board with the help of a marker pen. At the end, the simulation results and conclusions are given to prove that the response follows the command with negligible error. Hence, this type of hybrid manipulator is suitable to be used in multi-fingered robotic grippers, pick and place operations, moving things etc.

The major reasons of the road accidents are the traffic problem and human erroneous driving. The researchers have started developing self-driving cars to avoid such accidents. In this paper, bicycle vehicle model along with its inverse vehicle dynamic model have been developed to track the predefined path and replace the driver. A bicycle vehicle model using bond graph (BG) is created to avoid single and two obstacles of known different geometry in predefined path. The obstacle avoidance algorithm is developed in the Matlab environment and this consists of combination of line following, tangent bug and wall following algorithm. The trajectory data from the obstacle avoidance controller is fed to the inverse controller of bicycle vehicle model to run the forward model of bicycle vehicle. For the trajectory tracking of bicycle vehicle model, the system inversion is carried out through the bond graph-based overwhelming controller. The simulation results for trajectory tracking of bicycle model is presented for single and two static obstacles with different orientations and shapes, and finally, conclusions are presented to show that response of the forward model follows the command (actual path decided by the obstacle avoidance controller) within the acceptable limits. All the results and simulations are obtained using Matlab and $${Symbols Shakti}^\circledR $$ software (Bond graph software).

This paper deals with the modelling and obstacle avoidance of a biped robot. At first, the bond graph-based three-dimensional model of the biped is proposed. The robot walking scheme depends upon the oscillating cylinder mechanism. Two DC motors are actuating the prismatic leg of the robot. Then, bond graph model is converted into the Simulink block which is further used for obstacle avoidance application. The physical model of the biped robot is also fabricated. The second part of the work deals with the development of the hybrid obstacle avoidance algorithm by using the merits of the line following, tangent bug and wall following algorithm. The practicability of algorithm is validated on two cases depend upon the positions of the obstacle. The coding of the algorithm is developed by using MATLAB software. The single rectangular shape obstacle is considered for obstacle avoidance by the robot during experimentation work. At last, the validation of the simulation and experimentation work is considered.

The hybrid manipulators have benefits of both serial as well as parallel manipulators. In this paper, a planar hybrid manipulator with six degrees-of-freedom is proposed; it consists of two parallel manipulators each having three degrees-of-freedom. The models for forward and inverse dynamic analysis of this manipulator are presented with bond graph approach. The actuators of the manipulator have ball screw feed drive mechanism to convert rotary motion into linear motion. There are basically three problems addressed in the paper. First, the models are simulated for trajectory tracking of a semi-circular path traced by the lower manipulator initially and then tracking of another semi circular path by upper manipulators. The second problem addressed is to develop the bond graph model of the hybrid manipulator with proportional control to reach a desired position from an initial position with an unity slope after few seconds. Finally, workspace analysis for given semi-circular trajectory is done with calculation of area of the workspace of lower, upper and hybrid manipulators. It is observed from the simulation that the response follows the desired trajectory within the permissible limit. The result indicates that manipulator follows nearly tangential path. It is seen from the result that the desired trajectory lies within the workspace boundary.

With an increase in number of knee problems in patients., the demand for the rehabilitation has increased. Most of the rehabilitation trainings are expensive and time consuming. So., the need for personalized treatment in rehabilitation is increasing. The knee exoskeleton is one of such solutions to assist the patients suffering from weal knee., paraplegia and hemiplegia. These exoskeletons meet the patient’s expectation in terms of assistance required and wearing comfort. These are relatively more portable than lower body exoskeletons owing to their lighter weight. These can either be used for gait rehabilitation., providing assistance during sit to stand motion., normal walking and running., for load carrying augmentation or for performing activities of daily living. In this work., a knee exoskeleton consisting of a linear actuator and surface Electromyography sensor is designed and fabricated. Experiments are performed to validate the results with those of theoretical one. The developed knee exoskeleton is found to be well suited for assisting the wearer during the rehabilitation.

The road accidents due to traffic problems and human erroneous driving are the major challenges for researches. The self-driving car or mobile robot is the solution to avoid such mishaps. In this paper, an attempted has been made to develop obstacle avoidance algorithms for bicycle vehicle model of mobile robots. The hybrid obstacle avoidance algorithm is proposed on the merits of line, wall following and tangent bug algorithm. The trajectory generated from the hybrid obstacle avoidance algorithm is fed into the overwhelming controller of the bicycle vehicle model of mobile robot for avoiding obstacles. Then, the fuzzy logic (FL) based obstacle avoidance controller is proposed. Twenty-three set of rules are proposed for fuzzy logic approach. Both the obstacle avoidance algorithms are implemented on the bicycle vehicle model of the mobile robot. The dynamic model of the mobile robot is developed using bond graph theory and is converted into Simulink block using S-function directly from the library of SYMBOLS Shakti software. The vehicle model is equipped with three ultrasonic sensors to measure the distance from the obstacles. Three input membership functions and one output membership function are considered in fuzzy logic controller. During avoiding two static obstacles and reaching the target, the comparison of obstacle free paths traced by both obstacle avoidance algorithms is done in this paper.

This paper deals with the reconfiguration of an intelligent autonomous vehicle that utilizes an automatic navigation method and online supervision system and thus can be used to improve the safety, traffic management and space optimization inside the confined space of a port. The bond graph model of the vehicle’s dynamic system is developed in a modular and hierarchical modelling environment. An over-actuated intelligent autonomous vehicle with redundant actuators has four independent driven wheels, four independent braking wheels and a four-wheel steering system. This vehicle can be safely operated with appropriate control law restructuring even when some of its actuators are unusable due to a fault. For actuator fault detection, analytical redundancy relations, which are constraint relations that describe nominal system behaviour and are written in terms of the measured system variables, are derived from the bond graph model. Analytical redundancy relations are continuously evaluated to generate residual signals and the symptoms in these signals are monitored for actuator fault detection and isolation. Once one or more actuator faults are isolated, the system is reconfigured via the selection of an appropriate operating mode to prevent critical or accidental situations. This procedure is validated by considering a fault scenario with two reconfiguration options.

An overwhelming controller-based implicit system inversion scheme is proposed in this work to control a hydraulically driven planar (three-degrees-of-freedom) parallel manipulator. The physical model-based design of the controller is developed by using bond graphs. The electro-hydraulic actuator in the leg is modelled by including the dynamics of the servo-valve and the cylinder. A leg-space force-feedback controller is proposed for controlling the hydraulic pressures acting on the pistons of the actuators. The objective is to develop a fast inverse model which is suitable for real-time implementation in the controller. It is shown that an approximate inverse model which correctly represents the kinematics of motion but has incorrect representation of inertias is sufficient for the controller design because of the high feedback gains used in the overwhelming control strategy. This controller, based on the approximate simple inverse model, generates the right driving forces for the actual system whose model is much more complicated and uncertain. Finally, the controller design for a planar vehicle simulator is considered as an example and the corresponding simulation results are used to validate the robustness of the model-based overwhelming controller to the modelling uncertainties.

Overwhelming controllers have been successfully used in the past for trajectory and impedance control. An overwhelming controller uses an image or copy of the system model in the model-based controller. This model represents the kinematic constraints for implicit system inversion. The controller output is used to actuate the controlled system through a high feedback gain, which ensures that the dynamics of the controller overwhelms the plant dynamics. The overwhelming controller implementation for a serial robotic system is a straightforward task. However, implementation of a bond graph model-based overwhelming controller for a parallel manipulator shows up a few difficult causal loops. Removal of these causal loops and a few other subtle modifications yield a computationally efficient inverse model for real-time implementation. As validation of the developed approach, trajectory tracking in constrained planar welding operation is considered. The corresponding simulation results are presented.