Tech Briefs
Truck of the future

Volvo Trucks North America, Lockheed Martin Control Systems, and Radian are involved in a joint effort to develop a hybrid electric demonstrator truck for the U.S. Army's 21st Century Truck Initiative.

Volvo Trucks North America, Lockheed Martin Control Systems, and Radian are building a Class 8 tractor powered by a hybrid electric propulsion system for the U.S. Army. Delivery of the demonstrator truck to the Army's Tank-automotive and Armaments Command (TACOM) is expected by December. "This project is an opportunity for Volvo and its partners to define the transportation model of the future," said Marc F. Gustafson, President and CEO of Volvo Trucks North America.

The hybrid electric truck will be propelled at low speeds by two 186-kW (250-hp) electric motors and at high speeds by a 343-kW (460-hp) diesel engine. Lead acid batteries charged by an onboard generator will power the electric motors. Volvo engineers are currently overseeing the integration of Lockheed Martin's HybriDrive propulsion system with the driveline and electrical systems on a Volvo VNL highway tractor. Testing began in January at several military sites in the U.S., including the Aberdeen Proving Grounds. Real-time data from the operational tests is being transmitted from the vehicle to both government research labs and facilities at the University of Michigan's Transportation Research Institute. Some or all of the technologies being developed on the truck could be ready for commercial use within seven years.

The propulsion system is designed to combine the power of the diesel engine with the power of an electric motor for shift-free acceleration. The combination of the two technologies could significantly reduce emissions while simultaneously increasing fuel efficiency without sacrificing performance, according to Keith Brandis, Vice President - Business Offer Development, Volvo Trucks. "Drivetrain technology is advancing so quickly that we must change the way we think of 'electric' power," Brandis said. "We expect this truck to demonstrate unprecedented acceleration and provide drivers more power than today's high-torque, high-horsepower engines. We also expect that the system will reduce operational costs due to greater fuel efficiency and reduced engine-maintenance requirements because of the elimination of the mechanical transmission and reduced workload on the engine."

An additional goal of the project is to investigate methods to make battery technology more practical for use in commercial applications. In the near future, it should be possible to reduce the weight and number of batteries by 50%. Concurrent with the project's goals to improve fuel efficiency and reduce environmental effects, the future tractor will be equipped with advanced safety systems. "Traffic safety is a critical issue for the Army, just as it is for commercial motor carriers," Brandis said. "Historically, 42% of peacetime fatalities suffered by the Army have occurred in convoy accidents."

In addition to an Eaton Vorad collision-warning system, the truck will feature a lane-tracking system that will warn the driver of an inadvertent lane change so that corrective actions can be taken. It will also include an electronically enhanced vision system for the operator. The electric motors will also be used as an auxiliary retarder. During brake applications, the motor's magnetic field will be reversed to provide increased stopping ability, which is projected to double brake life. The auxiliary retarding effect of the electric motors will also be used to recharge the batteries.

Jean L. Broge