Richard Welch

The Rocky 7 rover: a Mars sciencecraft prototype

This paper describes the design and implementation at the Jet Propulsion Laboratory of a small rover for future Mars missions requiring long traverses and rover-based science experiments. The small rover prototype, called Rocky 7, is capable of long traverses, autonomous navigation, and science instrument control. This rover carries three science instruments, and can be commanded from any computer platform from any location using the World Wide Web. In this paper we describe the mobility system, the sampling system, the sensor suite, navigation and control, onboard science instruments, and the ground command and control system. We also present key accomplishments of a recent field test of Rocky 7 in the Mojave Desert in California.

Guiding conceptual design through behavioral reasoning

This paper presents a model for conceptual design based on an explicit behavioral reasoning step to guide the design process. Rather than mapping directly from function to form, we treat conceptual design as a two-step process, first transforming functional requirements to a behavioral description and then matching physical artifacts to this behavior. We believe that behavior, in terms of physical principles and phenomena, provides a natural bridge between functional requirements and physical artifacts. Behavioral reasoning breaks preconceived links between functions and artifacts, allowing for innovative solutions to be found. A new representation calledbehavior graphs (derived from bond graphs) has been developed to facilitate behavioral reasoning. This paper discusses behavior graphs and their use in a design synthesis model that generates systems of pre-defined embodiments (e.g., motor, spring, valve) to meet functional requirements given in terms of input and output parameters (e.g., force, pressure, displacement, voltage). An experimental computer program implementing this model is discussed and illustrative examples presented.

A prototype manipulation system for Mars rover science operations

This paper provides an overview of a new manipulation system developed for sampling and instrument placement from small autonomous mobile robots for Mars exploration. Selected out of the design space, two manipulators have been constructed and integrated into the Rocky 7 Mars rover prototype. This paper describes the design objectives and constraints for these manipulators, and presents the finished system and some results from its operation.

Systems engineering the Curiosity Rover: A retrospective

This paper will discuss systems engineering challenges in development of the Mars Science Laboratory Curiosity Rover. As of the writing of this paper, Curiosity has been successfully exploring the surface of Mars for months, but during development it was not always clear it would be a success. MSL is by design three spacecraft in one: The cruise system to get from Earth to Mars; the entry descent and landing system; and the Rover to perform the intended scientific exploration. Each of these has it own unique challenges and is intertwined given the integrated nature of the design. The rovers complex science payload, sampling system and overall scale resulted in many technical challenges. This paper will present a few examples of the systems engineering challenges overcome during the development of the Curiosity rover.

The Mars exploration rover: an in situ science mission to Mars

In this paper the concept for a mobile vehicle system which performs an in situ science mission to Mars is described. This rover mission with its requirements for driving, positioning at science selected targets, and remote and in situ measurement will utilize the technologies for hazard avoidance and autonomous navigation supported by ground operation tools which use rover-based imagery for position estimation and motion planning.

Verification and validation of Mars Science Laboratory surface system

This paper will discuss the system level verification and validation test program for the surface capability of the Mars Science Laboratory (MSL) Curiosity Rover. MSL has many similarities to its predecessors, the Mars Exploration Rovers Spirit and Opportunity. However, Curiositys diverse science payload, new sampling system, and overall scale led to new challenges in development and testing. The rover hardware and software were developed to allow certain functions to work in parallel to maximize the science that could be done each day on Mars. This led to complex behavioral interactions, which had to be tested and verified before they could be trusted. An incremental test program was developed that first exercised and verified individual functions and then validated system capabilities in mission-like scenarios. The plans, execution and results of these mission-like surface system tests will be presented.

Verification and validation of Mars Exploration Rover surface capabilities

This paper will discuss the system level verification and validation test program for the surface capability of the Mars Exploration Rovers (MER). The Mars Exploration Rover project was implemented on an extremely challenging schedule of going from concept to launch in just three years. Although the cruise and entry, descent and landing (EDL) systems were based on the successful Mars Pathfinder mission of 1997, the MER rovers and their sophisticated science payload were a new development and the expectations for the surface capability were very high. The rover hardware and software were developed to allow certain functions to work in parallel to maximize the science that could be done each day on Mars. However this lead to complex behavioral interactions which had to be tested and verified before they could be used. An incremental test program was developed that first exercised and verified individual functions and then validated system capabilities in mission-like scenarios. The plans, execution and results of these mission-like surface system tests will be presented.