SuperGLS
07-07-2005, 09:11 AM
Citroën Technology Testers
On the technology front, Citroën announced that it has two interesting projects under development. The first is an application of the aviation "fly by wire" principle to the automobile. The company has adapted one of its C5 sedans as a test-bed for "drive by wire," which concentrates all the control elements normally shared between the pedals and the steering wheel in the steering wheel itself. An automatic gearbox means the driver does not have to use any form of shift lever. The 'wheel' is shaped like that of an aircraft, with no top and bottom sections, and acceleration and braking are effected by buttons on the wheel's grips. The wheel no longer needs to be circular because the steering system uses an infinitely-variable power assistance that has particularly increased assistance at low speed and for parking maneuvers.
The wheel is designed so that acceleration and braking are carried out with the thumb and first finger of either hand. The controls are duplicated so that the normal stalks controlling turn indicators, windshield wipers, and lights can be operated at the same time as accelerating or braking. An electronic cruise control/speed-limiter system means that the driver does not have to apply constant pressure to the accelerator button.
The power assistance system for the electrically-controlled steering covers a wide range; thanks to a speed-sensitive control that gives the driver so much help at low parking speeds that the vehicle can go from lock to lock with just one-third of a turn of the wheel rather than the three turns required for a conventional system.
The electro-hydraulic braking system is similar to those already in use, apart from the fact that it is controlled by the buttons on the wheel rather than a foot-pedal. Citroen claims that it is just as progressive as a foot-operated system, reacting to the amount of pressure applied to the button to apply the brakes gently or hard.
The electric steering means that the steering-column is redundant, and the movement of the braking control to the wheel means that the pedal-box is also unnecessary. The removal of these two items would make a major contribution to safety in a frontal crash, making the drive by wire system valuable addition to production cars.
The second Citroën development calls to mind the small display ads for the latest breakthroughs in domestic technology. In this case, it's "Say Goodbye to Parking Blues!" that is the selling point. Citroën has built one of its C3 compact sedans with a system that automatically measures the gaps between cars parked at the side of the road. When it finds one that's big enough, it will automatically parallel-park, without any action from the driver other than selecting forward and reverse gears in response to visual and spoken commands from the car.
Operational at speeds below 15 mph, the system uses three distance sensors, mounted in the front and rear bumpers, to spot a space large enough for the car to enter. Normally it searches for spaces on the passenger side, but it can be made to look for spaces on the driver's side by operating the turn-signal stalk. Once it identifies a space, a signal sounds. If the driver agrees it's a good place to park and applies the brakes, the auto parking system comes into operation and takes control of the steering. The driver need not touch the wheel, merely engage forward and reverse gears as instructed by the electronic brain. The operation is not completely under the control of the brain, however. The driver has only to touch the wheel to retake full control. -Ian Norris
From TCC.
On the technology front, Citroën announced that it has two interesting projects under development. The first is an application of the aviation "fly by wire" principle to the automobile. The company has adapted one of its C5 sedans as a test-bed for "drive by wire," which concentrates all the control elements normally shared between the pedals and the steering wheel in the steering wheel itself. An automatic gearbox means the driver does not have to use any form of shift lever. The 'wheel' is shaped like that of an aircraft, with no top and bottom sections, and acceleration and braking are effected by buttons on the wheel's grips. The wheel no longer needs to be circular because the steering system uses an infinitely-variable power assistance that has particularly increased assistance at low speed and for parking maneuvers.
The wheel is designed so that acceleration and braking are carried out with the thumb and first finger of either hand. The controls are duplicated so that the normal stalks controlling turn indicators, windshield wipers, and lights can be operated at the same time as accelerating or braking. An electronic cruise control/speed-limiter system means that the driver does not have to apply constant pressure to the accelerator button.
The power assistance system for the electrically-controlled steering covers a wide range; thanks to a speed-sensitive control that gives the driver so much help at low parking speeds that the vehicle can go from lock to lock with just one-third of a turn of the wheel rather than the three turns required for a conventional system.
The electro-hydraulic braking system is similar to those already in use, apart from the fact that it is controlled by the buttons on the wheel rather than a foot-pedal. Citroen claims that it is just as progressive as a foot-operated system, reacting to the amount of pressure applied to the button to apply the brakes gently or hard.
The electric steering means that the steering-column is redundant, and the movement of the braking control to the wheel means that the pedal-box is also unnecessary. The removal of these two items would make a major contribution to safety in a frontal crash, making the drive by wire system valuable addition to production cars.
The second Citroën development calls to mind the small display ads for the latest breakthroughs in domestic technology. In this case, it's "Say Goodbye to Parking Blues!" that is the selling point. Citroën has built one of its C3 compact sedans with a system that automatically measures the gaps between cars parked at the side of the road. When it finds one that's big enough, it will automatically parallel-park, without any action from the driver other than selecting forward and reverse gears in response to visual and spoken commands from the car.
Operational at speeds below 15 mph, the system uses three distance sensors, mounted in the front and rear bumpers, to spot a space large enough for the car to enter. Normally it searches for spaces on the passenger side, but it can be made to look for spaces on the driver's side by operating the turn-signal stalk. Once it identifies a space, a signal sounds. If the driver agrees it's a good place to park and applies the brakes, the auto parking system comes into operation and takes control of the steering. The driver need not touch the wheel, merely engage forward and reverse gears as instructed by the electronic brain. The operation is not completely under the control of the brain, however. The driver has only to touch the wheel to retake full control. -Ian Norris
From TCC.