The ByWire XGV™ provides an integration-ready, drive-by-wire controlled ground vehicle and mobile robot platform for researchers and developers of unmanned vehicles. Jump start your research by staying focused on developing more advanced robotic technologies.
Driven by real-world applications and experiences such as the DARPA Urban Challenge, the design of the ByWire XGV focuses on reliability, safety, cost-effectiveness, and performance. The conversion package revolves around three core areas: drive-by-wire, safety, and power. Drive-by-wire is the ability for a computer to perform both closed-loop and open-loop control of the vehicle, safety revolves around a fail-safe emergency stop system, and on board power provides a set of flexible options for supplying power to any auxiliary equipment you might need.
The ByWire XGV™ utilizes the Ford Escape Hybrid's proven vehicle systems, tapping into electronic controls, available battery power, and on-road / off-road ruggedness for flexibility of application. Controlled through a unified Ethernet interface, the drive-by-wire conversion is seamlessly integrated with the Hybrid Escape factory electronics. The ByWire XGV provides electronic control of the steering, throttle, shifter, braking, and signals. In addition, information such as vehicle speed, warnings, and errors can be monitored. The need to interface easily with your third party technology is central to the design, which is why the clean conversion leaves the trunk, front and rear seats unaltered, leaving plenty of room for installing hardware either in factory installed racks or using your own mounting solution.
The integrated SafeStop™, a wireless emergency stop system with a 6 mile line-of-sight range, provides emergency stop functionality. Manual stop buttons are mounted inside and outside of the vehicle for additional safety. A key benefit of the XGV is the availability of onbaord electric power, which prevents the need for adding additional sources of power to the system. The optional PowerHub™ power conditioning and distribution modules allow for use of up to 6 kW of managed power, which are configurable over Ethernet through a web browser.
The ByWire XGV embedded controller, along with all other modifications to the vehicle, are hidden entirely from view. Interfacing with the controller, however, is done via an accessible Ethernet port mounted in the center console. Through this port, the vehicle is controlled using the SAE AS-4, Joint Architecture for Unmanned Systems (JAUS) protocol. Following this standard makes the ByWire XGV compatible with any other independently developed hardware or software that also follows the protocol. Examples include higher-level decision making software, motion planning algorithms, perception modules, as well as a 3rd party Operator Control Unit (OCU).
Using JAUS messages, the vehicle can be controlled in both open-loop mode and closed-loop mode. In open-loop mode, you can directly control the throttle, brake, steering percentage, and the gear shifter. This is the lowest-level of control and most closely replicates the typical driving experience for teleoperation and remote control. In closed-loop mode, you can command vehicle speed, curvature, and accelerations, allowing for higher-level path control. This mode of control is most useful for the implementation of autonomous or semi-autonomous driving algorithms.
Switching between control modes and actively controlled vehicle systems is simple and intuitive. Managed using stock dashboard and steering column controls or through JAUS messages, the XGV also has operation modes for debugging and testing. For example, choosing manual speed allows you to test your steering control algorithm while maintaining driver control of throttle and braking functions for safety. To transfer control of the vehicle to a computer, both the system activation key must be enabled and the gear shift must be placed in neutral. Therefore, taking control back from the computer is as easy as shifting the vehicle back into drive and taking hold of the steering wheel.
The XGV embedded controller also taps directly into the stock vehicle systems, allowing for control of, and providing feedback from, factory systems and devices such as turn signals, hazard lights, headlights, engine startup/shutdown, and the horn. The XGV can even tell when the door is open or the parking brake is activated, and in such a situation, prevent the vehicle from moving under computer control.
The most important safety feature of the ByWire XGV comes in the form of the integrated SafeStop™ system, a multi-level, wireless emergency stop system for unmanned ground vehicles. It is a safety-line, giving a human operator the ability to remotely disable or pause the vehicle at any time, protecting the time, money, and resources you have invested. Pausing brings the vehicle to a controlled stop at 3 m/s2 while leaving control of the steering in the hands of the computer. Disabling applies 100% brake, and can be configured to shut-off the engine.
The frequency hopping spread spectrum radio helps to reduce interference. The hand-held unit features control of independent pause and stop relays, a 30 hour battery life, visual and audio feedback, and a range of up to 6 miles line-of-sight.
A key benefit using the Ford Escape Hybrid is the availability of onboard electric power. This prevents you from having to add an additional power source such as batteries or a generator. The PowerHub™ power conditioning and distribution options harness this resource and provide you with up to 6 kW of managed power. This is available as direct current as well as alternating current, depending on your application and power needs. Furthermore, an Ethernet interface to the PowerHub allows for health monitoring software to easily detect power failures. Subsequently, power to various components can be programmatically reset without the need for human intervention.
Several stand alone components comprise the PowerHub. All components, however, are rack mountable for easy installation in the rear of the XGV. First, a high voltage DC to DC converter is used to integrate with the 330V hybrid power supply located in the trunk of the vehicle. This is then combined with an AC/Shore Power option that allows for 2.2 kVA max AC power and battery backup. The battery backup enables the system to be hot swapped from vehicle power to shore power. Both 12V and 24V distribution modules can then be added, with each module providing 8 configurable current outputs for a total distribution of up to 400W.
Every unmanned systems developer at some point has been faced with the “base platform problem.” In order to test and develop any type of advanced unmanned systems technology, whether it is a new piece of control software, safety system, or perception algorithm, you typically begin in simulation. Proving the actual effectiveness requires testing and development in the real world. In order to do this, a base drive-by-wire vehicle platform is usually needed. It is then that you are confronted with the “base platform problem” and the many questions it poses.
The ByWire XGV is a direct solution to the “base platform problem” experienced by so many engineers, integrators, and researchers in the unmanned systems community. As an off-the-shelf test platform with great flexibility, the XGV is ready for the integration of your technologies.
Continually redesigning and rebuilding a base platform is a waste of time and money. Instead, let a company with years of experience in UGV development take lessons learned, from applications like the DARPA Urban Challenge, and provide an off-the-shelf drive-by-wire platform that is safe, reliable, and cost effective. Minimize guess-work with the knowledge that your base platform has been thoroughly tested, that all systems are well documented and properly supported, and that your solution is scalable should you progress to a multi-agent system.
In total, the ByWire XGV provides a seamless, clean conversion of a Ford Escape Hybrid to drive-by-wire control with tightly integrated safety components and an onboard power management system. Whether you are a software developer improving situational awareness for teleoperation, a researcher developing off road path planning algorithms, or an automaker testing new safety systems, the ByWire XGV is the base platform that you need.
