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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.

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).

The control of cardiovascular system by autonomic nervous system using model-based analysis is very useful to predict blood flow and blood pressure at different locations of human body. The regulation of cardiovascular system by autonomic nervous system is a very complex mechanism, so, an experimental-based model analysis may prove very helpful in studying and analysing its working properly. In this article, a very basic model of cardiovascular system is presented with blood pressure dynamics studied throughout the body. A new bond graph model of the autonomic nervous system embedded with baroreflex system is also presented. Autonomic regulation of ventricular contractility is represented by means of transfer functions. The results in terms of maximum ventricular elastance ([Formula: see text]) and end systolic pressure are shown for two experiments. Another alternative modelling approach to represent the function of nervous system action in blood pressure regulation in terms of an overwhelming controller has been proposed. This controller overwhelms the system properties and therefore helps in managing the unmodelled parts or properties of a system and makes it impeccable for controlling complex systems. All the results and simulations are obtained using Symbols Shakti® 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.

Industrial robots, generally, are composed of architecture with serial manipulators having large workspace but these suffer from several drawbacks, such as low accuracy and low load-carrying capacity. Similarly, the parallel architecture robots have better accuracy but small workspace. Therefore, the combination of serial and parallel chain architectures has become attractive as hybrid manipulators over the last two decades. A planar hybrid manipulator is proposed here and this is made by placing a planar parallel manipulator, having three degrees of freedom, each over the other in series so as to increase its load-carrying capacity and then it is modeled with the help of the bond graph approach. The human vertebrae are considered as a hybrid manipulator in this paper. The translation of the human vertebrae model on the frontal plane and lateral bending in the right- and left-hand directions are proposed here to increase the flexibility of the body part of humanoid robots used in industries and sports so that they can execute spine bending activities. The forward and inverse models for the manipulator are presented and the system inversion is carried out through the overwhelming controller. Finally, the simulation results for trajectory tracking of left-hand lateral bending in the frontal plane is done with or without the consideration of leg inertia and conclusions are presented to show that response follows the command within acceptable limits.

In the present paper three dimensional cutter deflections and the corresponding profile errors during end milling are predicted by finite element and bond graph modeling approach. The deflections have been modeled considering the cutter as a cantilever beam fixed at the collet end. Rayleigh beam model is used for modeling to consider the shear force effect, and Castigliano's theorem of strain energy is used to predict the deflections due to radial, tangential, and axial cutting forces. The tool-workpiece contact region is sliced into small elements to apply the forces on the entire contact region and predict deflections more accurately. The predicted deflections at different parametric settings are compared with experimental measurements by measuring the geometric accuracy of the cut profiles. The depth of cut has the most significant influence on profile deviations, while feed and speed have marginal effects. The results reveal that the predictions by finite elements and the bond graph closely matches wi...

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 provides robustness against uncertain parameters, disturbances and un-modelled dynamics. A simplified inverse dynamics model is used in the present paper to develop an overwhelming controller for a parallel manipulator (a Stewart platform), where the controller accommodates modelling uncertainties such as the simplifications made for development of the inverse model in order to improve the computational efficiency. Such a control strategy leads to good trajectory tracking accuracy in the presence of unknown disturbances. However, in addition to trajectory tracking performance, the controller for a Stewart platform should also be able to control or limit the interaction forces in applications such as robot assisted surgery and low-impact docking. The environmental forces can be accommodated during the interaction period by modulating the impedance at the interface of manipulator and environment through virtual flexible foundations. The positional error induced during the force control phase can be recovered during the free flight or idle phase. While this approach has been used successfully in the past to control serial manipulators, the closed loop kinematic architecture in a parallel manipulator introduces many difficulties. This paper proposes a modified overwhelming control scheme for parallel manipulators with compensations for interaction force control and positional error recovery. Bond graph modelling is used as an integrated model and controller development tool. Force controlled machining on a spherical surface, which is akin to a surgical operation, is considered as an example application of the developed control strategy. The simulation results from the bond graph model of the controlled Stewart platform are presented to demonstrate the performance of the developed hybrid position force controller.

Neglecting dynamic load during design of a prismatic joint for high-speed operation may lead to unpredictable failures. A slider joint is usually a part of a pneumatic or hydraulic actuation device which may further involve complicated control systems. Thus, design/analysis of prismatic joints calls for a multi-energy domain modeling approach such as bond graph for reusability of the model in different application scenarios. The slider is treated to be a multibody system composed of two separate rigid bodies which are constrained to produce the desired motion. The constraints generate the dynamic contact forces which are used to compute the dynamic frictional forces. The bond graph model of the planar slider component developed in this article accurately calculates the dynamic loads. The model is first validated through numerical simulations performed on a Rapson slide. Thereafter, a multi-energy model for a V-twin engine and its mounting is developed to show how bond graph modeling makes it possible to create an integrated model of thermal, pneumatic and mechanical systems. Finally, the bond graph model of a three-dimensional prismatic joint is developed.

Antilock braking system (ABS), traction control system, etc. are used in modern automobiles for enhanced safety and reliability. Autonomous ABS system can take over the traction control of the vehicle either completely or partially. An antilock braking system using an on–off control strategy to maintain the wheel slip within a predefined range is studied here. The controller design needs integration with the vehicle dynamics model. A single wheel or a bicycle vehicle model considers only constant normal loading on the wheels. On the other hand, a four wheel vehicle model that accounts for dynamic normal loading on the wheels and generates correct lateral forces is suitable for reliable brake system design. This paper describes an integrated vehicle braking system dynamics and control modeling procedure for a four wheel vehicle. The vehicle system comprises several energy domains. The interdisciplinary modeling technique called bond graph is used to integrate models in different energy domains and control systems. The bond graph model of the integrated vehicle dynamic system is developed in a modular and hierarchical modeling environment and is simulated to evaluate the performance of the ABS system under various operating conditions.

Combined regenerative and antilock braking in electric/hybrid-electric vehicles provides higher safety in addition to an energy storing capability. Development of a control law for this type of braking system is a challenging task. The antilock braking system (ABS) uses a control strategy to maintain the wheel slip within a predefined range. A sliding mode controller (SMC) for ABS is developed to maintain the optimal slip value. The braking of the vehicle, performed by using both regenerative and antilock braking, is based on an algorithm that decides how to distribute the braking force between the regenerative braking and the antilock braking in emergency/panic braking situations as well as in normal city driving conditions. Detailed bond graph models of a quarter car and four-wheeled vehicles are used in this article to implement and test the control laws. It is found that with combined regenerative and antilock braking, the vehicle’s safety increases (in terms of stopping distance and manoeuvrability) and some amount of kinetic energy can be recovered and stored in the regenerative battery pack. The passenger comfort is improved when a sliding mode ABS controller is used in place of a standard ABS controller for the mechanical braking part. Moreover, the influence of load transfer on the wheels during braking was evaluated on a four-wheeled vehicle model.

This paper presents the modeling and real-time validation of an intelligent autonomous vehicle using the bond graph tool. Bond graph is a graphical and modular representation of systems residing in the different energy domains, and is a good tool for representing complex systems like heavy vehicle. The validated dynamics of the vehicle are the longitudinal and lateral ones. The model created from the bond graph modeling method is simulated with appropriate software. These two dynamics were validated by comparing its results with co-simulations obtained from professional real-time simulator of vehicle dynamics, named SCANeR Studio®. A circular path tracking was considered for the analysis of longitudinal and lateral dynamics of the considered Intelligent Autonomous Vehicle (IAV) in closed loop control.

The present work concerns prediction of the amount of heat accumulation within the interior of a framed glass cabin and proposes some remedial measures to reduce temperature in the cabin. Various configurations such as double layer glass box filled with static air, static argon gas and flowing argon gas within the space between the two glass-layers are considered to conduct the experiments. Multi-physics bond graph models for these configurations are developed considering thermo-fluidic aspects. The experimental results are compared with the simulations using bond graph models. Though, direct application to a vehicle is not made, without loss of generality, the modelling and experimental procedure can be extended to analyze the heat accumulation inside a vehicle cabin when the vehicle is parked under direct sunlight.

This article deals with modeling of an intelligent autonomous vehicle with four traction wheels, four braking wheels and four-wheel steering system. The bond graph model of the integrated vehicle dynamic system is developed in a modular and hierarchical modeling environment. The Ackerman steering concept was used in the steering motor controller. Simulation results show the advantages of four-wheel steering during tight maneuvers.