The Freightliner Group Demonstrates Advanced Heavy-Duty Truck Technologies at DaimlerChrysler Innovations Symposium
WASHINGTON, D.C…The Freightliner Group is showcasing the latest developments in heavy-duty truck safety technology at the DaimlerChrysler Innovations Symposium here. The Freightliner Group, a unit of DaimlerChrysler and the largest manufacturer of heavy-duty (Class 8) trucks in North America, is demonstrating advanced systems including electronic stability control (ESC), electronically-controlled braking systems, radar collision warning with adaptive cruise control, the Lane Guidance lane departure warning and a side visibility camera. Installed on a Freightliner Class 8 demonstration truck, these active safety technologies are designed to help truck drivers safely operate the vehicle and to help avoid heavy-duty truck accidents.
The DaimlerChrysler Innovations Symposium is a showcase of pioneering automotive and commercial vehicle technologies being held in conjunction with DaimlerChrysler’s Impact on America event in the U.S. capital.
“The Freightliner Group has pioneered the implementation of safety technology into North American heavy-duty trucks and we continue to evaluate advanced systems that demonstrate potential for enhancing commercial vehicle safety,” said Michael von Mayenburg, Freightliner Group Senior Vice President of Engineering & Technology. “Following DaimlerChrysler’s vision of accident-free driving, the systems and technologies being featured at the DaimlerChrysler Innovations Symposium are active safety technologies designed to prevent accidents from happening in the first place.”
According to von Mayenburg, technologies showcased at the Innovations Symposium include:
Electronic Stability Control
The new Electronic Stability Control (ESC) system is designed to increase overall vehicle stability by intelligently applying engine controls and individual wheel brakes when the stability of the truck enters a critical area.
The system works by controlling the yaw rate of the tractor and trailer on the road. It has the ability to compare the drivers steering input command with a vehicle’s response. In critical situations, when the vehicle does not follow the path the operator has requested, ESC corrects these conditions by individually applying wheel brakes at the appropriate corners of the vehicle to rotate it, thus correcting its actual path to match the driver’s request. In this kind of situation, the trailer brakes are also pulsed to assure that the combination remains stable throughout the event. The system has been developed in cooperation with Meritor-WABCO.
The ESC system also functions to avoid truck rollover by sensing the lateral acceleration of the vehicle and automatically slowing the truck to reduce the forces pushing the vehicle toward a rollover situation.
Electronically-controlled braking system (ECBS)
Today, most North American heavy-duty trucks incorporate air brake systems. Air brake systems transfer pedal input to the brakes via pneumatic control circuits (air lines) and pneumatic valves. An electronically-controlled braking system (ECBS), on the other hand, uses electronic circuits and electro-pneumatic valves to perform this function. With these capabilities, ECBS is viewed as a possible enabling technology that can provide shorter stopping distances, improved dynamic brake force distribution, improved combination vehicle brake balance and offer additional integrated features. Combined with electronic stability systems, ECBS can also offer improved control to commercial vehicle drivers, particularly under distressed maneuvers. Additionally, ECBS offers the potential for improved ABS functionality by permitting more precise control of wheel speed and it can provide the basis for additional advances and new features.
Lane Guidance is an advanced lane departure warning system. Lane Guidance monitors the truck’s position relative to lane markings, then sounds an audible warning when the truck is about to stray outside its lane. The advanced system is designed to avoid accidents by warning distracted or inattentive drivers of unintended lane changes.
The Lane Guidance system consists of a digital camera, mounted on the windshield inside the cab; a Central Processing Unit (CPU), located in the overhead console; two speakers located in the left- and right-side doors and associated wiring.
The camera continually gathers visual data, digitizes them and feeds them into the CPU. Using image recognition software and a lane recognition algorithm, the CPU determines if a vehicle is drifting too close to the lane markings. When this occurs -- and if the driver has not activated the turn signal -- the CPU sends a signal to emit a distinctive “rumble strip” sound.
When the truck is straying to the left, the warning sound comes from the left speaker. When the truck is straying to the right, it comes from the right speaker. The driver is intuitively expected to steer away from the side of the sound.
Radar Collision Warning with Adaptive Cruise Control
These radar-based systems are designed to alert the driver to a slower moving vehicle, or automatically maintain a safe following distance to the preceding vehicle.
A radar sensor tracks the speed, range and bearing of vehicles ahead. In case of unsafe following distance or fast approach to a slower vehicle, the system will sound a buzzer and display a warning symbol on a dash display. In adaptive cruise control mode, the system attempts to maintain a user-selected safe following distance to the preceding vehicle. It uses the throttle, engine brake or tractor foundation brakes to decelerate the vehicle. If the slower moving vehicle changes lanes or moves out of the way, the system automatically accelerates the vehicle to the specified cruise speed. These technologies are intended to increase driving safety and comfort, while contributing to fuel economy.
Sidetracker Video System
The Sidetracker video system is designed to give truck drivers visibility to the blind-spot or “No-Zone” on the right side of a tractor-trailer combination. The system utilizes a weather-proof color video camera with excellent resolution and special low distortion wide angle lens. Mounted on the existing right front fender mirror mount, the camera sends a picture through a special cable back to a color monitor located in the cab approximately 30-36 inches from the driver’s eyes. The monitor displays a view of the entire right side of the tractor-trailer extending beyond the back of the trailer as well as 5-6 lanes to the right, including entrance ramps.
In addition to electronic stability control, an electronically-controlled braking system, radar collision warning with adaptive cruise control, the Lane Guidance lane departure warning and a side visibility camera, the Freightliner demonstration truck at the Innovations Symposium features:
Anti-lock braking system
Daytime running lights for better conspicuity in daylight conditions
Anti-spray devices to protect traffic from spray
von Mayenburg pointed out that some of the systems on display at the Innovations Symposium are already available for production models, while others are being evaluated in field tests.
While emerging technologies hold considerable potential for enhancing heavy-duty truck safety, von Mayenburg explained that the truck driver will remain the key to safe heavy-duty truck operations. “The basis of safe operations will continue to be a skilled, trained truck driver.”
In addition to enhancing commercial vehicle safety, The Freightliner Group is also committed to reducing the environmental impact of commercial vehicles. The Freightliner demonstration vehicle at the Innovations Symposium featured a Detroit Diesel Series 60 engine with exhaust gas recirculation (EGR) system for reducing diesel engine emissions. EGR works by circulating cooled exhaust gas back into the engine air intake. This lowers combustion temperature and reduces the formation of NOx. Heavy-duty vehicles manufactured by The Freightliner Group will features engines with advanced EGR systems to meet upcoming 2007 U.S. EPA requirements.