Search results

The purpose of this paper is to evaluate the locomotion performance of all‐terrain rovers employing rocker‐type suspension system.

In this paper, a robot with advanced mobility features is presented and its locomotion performance is evaluated, following an analytical approach via extensive simulations. The vehicle features an independently controlled four‐wheel‐drive/4‐wheel‐steer architecture and it also employs a passive rocker‐type suspension system that improves the ability to traverse uneven terrain. An overview of modeling techniques for rover‐like vehicles is introduced. First, a method for formulating a kinematic model of an articulated vehicle is presented. Next, a method for expressing a quasi‐static model of forces acting on the robot is described. A modified rocker‐type suspension is also proposed that enables wheel camber change, allowing each wheel to keep an upright posture as the suspension conforms to ground unevenness.

The proposed models can be used to assess the locomotion performance of a mobile robot on rough‐terrain for design, control and path planning purposes. The advantage of the rocker‐type suspension over conventional spring‐type counterparts is demonstrated. The variable camber suspension is shown to be effective in improving a robot's traction and climbing ability.

The paper can be of great value when studying and optimizing the locomotion performance of mobile robots on rough terrain. These models can be used as a basis for advanced design, control and motion planning.

The paper describes an analytical approach for the study of the mobility characteristics of vehicles endowed with articulated suspension systems. A variable camber mechanism is also presented.

The purpose of this research is to explore the utility of autonomous transport across two independent airframe maintenance operations at a single location.

This study leveraged discrete event simulation that encompassed real-world conditions on a United States Air Force flight line. Though the Theory of Constraints (TOC) lens, a high-demand, human-controlled delivery asset is analyzed and the impact of introducing an autonomous rover delivery vehicle is assessed. The authors’ simulations explored varying numbers and networks of rovers as alternative sources of delivery and evaluated these resources’ impact against current flight line operations.

This research indicates that the addition of five autonomous rovers can significantly reduce daily expediter delivery tasks, which results in additional expertise necessary to manage and execute flight line operations. The authors assert that this relief would translate into enhancements in aircraft mission capable rates, which could increase overall transport capacity and cascade into faster cargo delivery times, systemwide. By extension, the authors suggest overall inventory management could be improved through reduction in transportation shipping time variance, which enhances the Department of Defense’s overall supply chain resilience posture.

When compared against existing practices, this novel research provides insight into actual flight line movement and the potential benefits of an alternative autonomous delivery system. Additionally, the research measures the potential savings in the workforce and vehicle use that exceeds the cost of the rovers and their employment.

The movement of firms towards joint ventures and collaborative projects has been a feature of the 1990s. Such agreements allow a means of spreading the costs and risks associated with new product development, sharing costly manufacturing capacity and facilities, and may also provide access to new capabilities. However, there are examples when the relationship is not a success for one of the parties involved. If firms enter joint ventures from a position of weakness or without a concerted strategy, they can become reliant on their partner. This was the case with Rover and its links to Honda. Because of financial weakness Rover’s design and manufacturing capabilities were eroded as the majority of its products were replaced with Honda developed models. This case provides important lessons and warnings for other firms seeking strategic alliances, and gives researchers an insight into the complex interaction between firms involved in such a relationship.

To provide an autonomous navigation system to endow lunar rovers with increased autonomy both for exploration achievement of scientific goals and for safe navigation.

First, algorithm and technique of initial position determination of lunar rovers are introduced. Then, matched‐features set is build by multi steps of image processing such as feature detection, feature tracking and feature matching. Based on the analysis of the image processing error, a two‐stage estimation algorithm is used to estimate the motion, robust linear motion estimation is executed to estimate the motion initially and to reject the outliers, and Levenberg‐Marquardt non‐linear estimation is used to estimate the motion precisely. Next, a weighted ZSSD algorithm is presented to estimate the image disparities by analyzing the traditional ZSSD. Finally, a virtual simulation system is constructed using the development tool of open inventor, this simulation system can provide stereo images for simulations of stereo vision and motion estimation techniques, simulation results are provided and future research work is addressed in the end.

An autonomous navigation system is build based on stereo vision, the motion estimation algorithm and disparity estimation algorithm are developed.

The field test will be done in the near future to valid the autonomous navigation algorithm presented in this paper.

A very useful source of information for graduate students and technical reference for researchers who work on lunar rovers.

In this paper, stereo vision‐based autonomous navigation techniques for lunar rovers are discussed, and an autonomous navigation scheme which based on stereo vision is presented, and the validity of all the algorithms involved is confirmed by simulations.

This study aims to find a feasible precise navigation model for the planed Lunar rover. Autonomous navigation is one of the most important missions in the Chinese Lunar exploration project. Machine vision is expected to be a promising option for this mission because of the dramatic development of an image processing technique. However, existing attempts are often subject to low accuracy and errors accumulation.

In this paper, a novel autonomous navigation model was developed, based on the rigid geometric and photogrammetric theory, including stereo perception, relative positioning and absolute adjustment. The first step was planned to detect accurate three-dimensional (3D) surroundings around the rover by matching stereo-paired images; the second was used to decide the local location and orientation changes of the rover by matching adjacent images; and the third was adopted to find the rover’s location in the whole scene by matching ground image with satellite image. Among them, the SURF algorithm that had been commonly believed as the best algorithm for matching images was adopted to find matched images.

Experiments indicated that the accurate 3D scene, relative positioning and absolute adjustment were easily generated and illustrated with the matching results. More importantly, the proposed algorithm is able to match images with great differences in illumination, scale and observation angle. All experiments and findings in this study proved that the proposed method could be an alternative navigation model for the planed Lunar rover.

With the matching results, an accurate 3D scene, relative positioning and absolute adjustment of rover can be easily generated. The whole test proves that the proposed method could be a feasible navigation model for the planed Lunar rover.

The aim of this paper is to understand how large and apparently successful organizations enter spirals of decline that are very difficult to reverse. The paper examines the case of Rover, once one of the largest car producers in the world, which collapsed in 2005. An analysis of strategic and operational choices made over a period of 40 years investigates the reasons for, and consequences of, a growing mismatch between the context faced by the company (industry dynamics, market conditions) and its operational capabilities, a mismatch that ultimately brought about the company's demise.

The paper is based on interviews with 32 people, including senior managers (including four chief executives), government ministers and union officials who were key decision makers within, or close to, the company during the period 1968 and 2005. Secondary sources and documentary evidence (e.g. production and sales data) are used to build up a historical picture of the company and to depict its deteriorating financial and market position from 1968 onwards.

The company was formed from a multitude of previously independent firms as part of a government‐sponsored agenda to build a UK National Champion in the car industry. The merged company failed due to several factors including poor product development processes, poor manufacturing performance, difficult labour relations, a very wide product portfolio and a lack of financial control. Although strenuous efforts were made to address those issues, including periods of whole or part ownership by British Aerospace, Honda and BMW, the company's position deteriorated until eventually production volumes were too low for viable operation.

The case of Rover highlights the importance of what has been termed “the management unit” in complex systems. The management unit comprises processes and routines to deal with challenges such as managing product portfolios, connecting strategic and operational choices, and scanning and responding to the environment. In the case of Rover, a number of factors taken together generated excessive load on a management unit frequently operating under conditions of resource scarcity. We conclude that viewing corporate failure from a systems perspective, rather than in terms of shortcomings in specific subsystems, such as manufacturing or product development, yields insights often absent in the operations management literature.

The paper is of value by showing corporate failure from a systems perspective, rather than in terms of shortcomings in specific subsystems, such as manufacturing or product development; and yields insights often absent in the operations management literature. The Rover case featured in the paper demonstrates the usefulness of systems ideas to understanding at least some types of failure, not as an alterative to capability‐based approaches, but in addition to them.

Describes Rover′s setting up of a quality strategy and policy based on a process model of the company, representing an integrated set of activities and goals which Rover must achieve in order to reach its vision. Discusses the Rover Group′s quality policy. Contends that failure to achieve any one milestone may have an effect on the achievement of the goal. Asserts it is only when the processes of the daily work are consistent, in harmony, and directed at customer satisfaction that Rover will be able to make its vision a reality. Concludes that Rover has now moved away from a quality system defined in detail from the centre to a delegated system which relies totally on people wanting to do it right.

A new manufacturing plant has been installed in Solihull, UK, to manufacture the new Range Rover sports utility vehicle. An important aspect of the £80 million investment at the site is a body‐in‐white assembly shop containing 123 robots, many of which are employed in multi‐tasking roles.

Contrasts theories of the “Japanization” of British industry with empirical evidence from established car producers in that industry. Suggests that while the UK car industry has been heavily influenced by Japanese methods, established producers follow policies marked by indigenous influences rather than by any unmediated Japanese effect. Proceeds to explore relationships between processual change in plant‐level work organization and the overarching context of institutions and ideas. Investigates the relevance of the two major theoretical models of workplace change in the motor industry ‐ the “diffusion” and the “bolt‐on” models of change ‐ and their conflicting interpretations of the impact of the Japanese “lean production” approach. Compares models with case‐studies of changing work practices at Rover and Peugeot and suggests that neither model provides a satisfactory account of the patterns of change found. Develops instead a model of change which emphasizes the creative adaptation of production practices within the British context.

The purpose of this paper is to resolve the problem of the dynamic response performance of the driving control system for a six-wheeled planetary rover. An adaptive sliding mode controller based on an improved genetic algorithm (IGA) to tune PID sliding surface parameters was used in the driving control system of the planetary rover.

First, the mathematical model of planetary rover driving control is established. Second, according to sliding mode variable structure control, an equivalent controller and a disturbance controller are constructed to solve the problem of a multi-disturbance nonlinear driving control system of planetary rovers and an IGA is used to tune PID parameters.

Simulation results show that the proposed control algorithm improves the accuracy of the driving control system and optimizes the smoothness of rover motion control.

The controller based on the IGA to tune PID sliding surface parameters has good self-adaptability and real-time controllability for the control object which is difficult to present a precise mathematical model.

The advanced control method is adopted to solve the uncertainty and external interference of planetary rovers in a complex environment. The mathematical model of the six-wheeled rover is established as the control object and the uncertainty and external disturbance of the model are considered. The controller based on IGA has good adaptability and real-time performance and the control algorithm can be used to drive robots in complex environments.