Path following hybrid control for vehicle stability applied to industrial forklifts

The paper focuses on a closed-loop hybrid controller (kinematic and dynamic) for path following approaches with industrial forklifts carrying heavy loads at high speeds, where aspects such as vehicle stability, safety, slippage and comfort are considered. The paper first describes a method for generating Double Continuous Curvature (DCC) paths for non-holonomic wheeled mobile robots, which is the basis of the proposed kinematic controller. The kinematic controller generates a speed profile, based on slow-in and fast-out policy, and a curvature profile recomputing DCC paths in closed-loop. The dynamic controller determines maximum values for decelerations and curvatures, as well as bounded sharpness so that instantaneous vehicle stability conditions can be guaranteed against lateral and frontal tip-overs. One of the advantages of the proposed method, with respect to full dynamic controllers, is that it does not require dynamic parameters to be estimated for modelling, which in general can be a difficult task. The proposed kinematic dynamic controller is afterwards compared with a classic kinematic controller like Pure-Pursuit. For that purpose, in our hybrid control structure we have just replaced the proposed kinematic controller with Pure-Pursuit. Several metrics, such as settling time, overshoot, safety and comfort have been analysed.This work was supported by VALi+d and PROMETEO Programs (Conselleria d'Educacio, Generalitat Valenciana), DIVISAMOS (DPI-2009-14744-C03-01) and SAFEBUS (IPT-2011-1165-370000): Ministry of Economy and Competitivity.Girbés, V.; Armesto Ángel, L.; Tornero Montserrat, J. (2014). Path following hybrid control for vehicle stability applied to industrial forklifts. Robotics and Autonomous Systems. 62(6):910-922. https://doi.org/10.1016/j.robot.2014.01.004S91092262

Clothoid-Based Three-Dimensional Curve for Attitude Planning

Interest in flying robots, also known as unmanned aerial vehicles (UAVs), has grown during last years in both military and civil fields [1, 2]. The same happens to autonomous underwater vehicles (AUVs) [3]. These vehicles, UAVs and AUVs, offer a wide variety of possible applications and challenges, such as control, guidance or navigation [2, 3]. In this sense, heading and attitude control in UAVs is very important [4], particularly relevant in airplanes (fixed-wing flying vehicles), because they are strongly non-linear, coupled, and tend to be underactuated systems with non-holonomic constraints. Hence, designing a good attitude controller is a difficult task [5, 6, 7, 8, 9], where stability must be taken into account by the controller [10]. Indeed, if the reference is too demanding for the controller or non-achievable because its dynamics is too fast, the vehicle might become unstable. In order to address this issue, autonomous navigation systems usually include a high-level path planner to generate smooth reference trajectories to be followed by the vehicle using a low-level controller. Usually a set of waypoints is given in GPS coordinates, normally from a map, in order to apply a smooth point-to-point control trajectory [11, 12]

Diseño e implementación de un sistema de adquisición de datos para la caracterización de los esfuerzos y movimientos del conductor en la conducción de vehículos automóviles

[ES] En este Trabajo Final de Grado se ha diseñado desde cero un sistema fiable, robusto y portátil de adquisición de datos para determinar los esfuerzos y movimientos que realiza el conductor de un vehículo automóvil. Este sistema, no solo se ha diseñado sino que también, se ha implementado en un vehículo real para realizar unas pruebas previas y así validar el sistema para que en un futuro muy próximo se realicen los ensayos correspondientes. El sistema incluye cuatro tipos de sensores distintos, todos ellos van conectados al ordenador principal encargado de ejecutar todos los procesos de medición. A lo largo de este documento se desarrolla todo el proceso que se ha seguido hasta llegar al sistema final, desde la elección de estos sensores y la calibración de los mismos , hasta el protocolo que se debe seguir con el ordenador para realizar la adquisición de datos. Durante este proyecto, también se ha indicado la normativa en la que se ha basado el proyecto al estar realizado en el entorno de un laboratorio de ensayo. Esta normativa nos sirve de base tanto a la hora de diseñar el sistema como en el momento de realizar las pruebas. De este modo se ha creado un sistema validado que ya está listo para que terceras personas realicen las pruebas oportunas y obtengan así una base de datos acerca de los movimientos y esfuerzos de los conductores , tratando así de cumplir con los objetivos descritos en la memoria del proyecto.[CA] En aquest Treball Final de Grau s'ha dissenyat des de zero un sistema fiable, robust i portàtil d'adquisició de dades per a determinar els esforços i moviments que realitza el conductor d'un vehicle automòbil. Aquest sistema, no solament s'ha dissenyat sinó que també, s'ha implementat en un vehicle real per a realitzar unes proves prèvies i així validar el sistema perquè en un futur molt pròxim es realitzen els assajos corresponents. El sistema inclou quatre tipus de sensors diferents, tots ells van connectats a l'ordinador principal encarregat d'executar tots els processos de mesurament. Al llarg d'aquest document es desenvolupa tot el procés que s'ha seguit fins a arribar al sistema final, des de l'elecció d'aquests sensors i el calibratge dels mateixos, fins al protocol que s'ha de seguir amb l'ordinador per a realitzar l'adquisició de dades. Durant aquest projecte, també s'ha indicat la normativa en la qual s'ha basat el projecte en estar realitzat a l'entorn d'un laboratori d'assaig. Aquesta normativa ens serveix de base tant a l'hora de dissenyar el sistema com en el moment de realitzar les proves. D'aquesta manera s'ha creat un sistema validat que ja està llest perquè terceres persones realitzen les proves oportunes i obtinguen així una base de dades sobre els moviments i esforços dels conductors, tractant així de complir amb els objectius descrits en la memòria del projecte.[EN] In this Final Degree Project, a reliable, robust and portable data acquisition system has been designed from scratch to determine the efforts and movements made by the driver of a motor vehicle. This system has not only been designed but also implemented in a real vehicle to carry out some previous tests and validate the system so that in the very near future the corresponding tests will be carried out. The system includes four different types of sensors, all of which are connected to the main computer in charge of executing all measurement processes. Throughout this document, the entire process that has been followed up to the final system is developed, from the selection of these sensors and their calibration, to the protocol that must be followed with the computer to carry out the data acquisition. During this project, the regulations on which the project was based were also indicated, as they were carried out in the environment of a test laboratory. This regulation serves as a basis both when designing the system and when carrying out the tests. This has created a validated system that is now ready for third parties to perform the appropriate tests and obtain a database on the movements and efforts of drivers, trying to meet the objectives described in the project report.Luna Serrador, ÁT. (2018). Diseño e implementación de un sistema de adquisición de datos para la caracterización de los esfuerzos y movimientos del conductor en la conducción de vehículos automóviles. Universitat Politècnica de València. http://hdl.handle.net/10251/114785TFG