In two years, the Lexus RZ 450e electric car with only electronic controls and a stick-like steering wheel will go on sale. The estimated base price is 1.715 million crowns. At the same time, electronic control is an option for an additional fee.
“Instead of the usual mechanical connection between the steering wheel and the front axle through the steering column, the driver’s instructions are transferred to the wheels electronically. The result is a faster response and more accurate transmission of instructions,” said Jitka Jechová, spokesperson of the Czech Toyota representative office, to which the Lexus concern belongs.
The system, called “sugar-by-wire”, should allow less steering when driving on uneven surfaces and more stable handling, as well as adjustment in strong winds.
The electric successor of the Lexus LFA will have a manual transmission
Lexus says the butterfly-shaped steering wheel has improved visibility. The instrument panel is slightly higher and further from the driver’s seat than in the case of the classic steering wheel, which makes it easier for the driver to refocus his vision between the road and the instruments.
Tesla also uses the same steering wheel in its electric cars, but even earlier – ten years ago – Nissan came up with an electronic steering wheel. He put it to Infiniti brand cars, which is its luxury branch, as Lexus is to Toyota.
Even then, manufacturers said that electric has a faster response than mechanical transmission due to the absence of mechanical losses and resistance. Formula 1 champion Sebastian Vettel, who at the time worked with Infiniti on the development of the car, took part in the development.
The car company at the time called the system Direct Adaptive Steering and it was first available in 2014 for the Q50 sedan. At that time, it was the first such system in a passenger car in the world, and it made it possible to change the driving characteristics and its resistance not only within the set driving modes, but the driver can also configure his own mode.
In addition, there are also potential benefits in weight savings, which translates into lower fuel consumption, and the easier conversion of right-hand drive, as driven in Japan, to left-hand drive used in many parts of the world. However, the Infiniti system was supplemented by a classic, physical combination between the steering wheel and the steering rack, which can be used in the event of a malfunction in the electronic system.
However, in 2016, the automaker had to recall about 60,000 Infinity sedans for service precisely because of the risk of the program’s different steering responses and changes in the turning radius after starting. So far, no other brand has come up with such a system.
The difference in the Toyota system is that there is no mechanical connection between the steering wheel and the front wheels, even as a protection in case of failure of the electronic system. Instead, there are two pieces of each section – one used as normal, the other as a backup in case the first one fails. The system also uses a 400V battery as standard, but in an emergency it can also run on a standard 12V battery. And if that fails too, it has its own small battery, so it should never happen that the driver loses control of the car.
There is still a steering wheel that uses rods and pins to turn the front wheels, but the rack only moves the gear driven by the electric motor. It receives signals from the control unit, which monitors how the driver turns the steering wheel.
The advantage is the endless and continuously variable steering gear and also the fact that the driver theoretically does not feel the steering wheel at all. A complete turn of the wheels can be achieved by simply turning the steering wheel 180 ° in one direction, but on the highway, for example, even a large turn of the steering wheel can mean only a small movement of the wheels.
Lexus introduced the RZ 450e, a futuristic electric SUV
“One of the main reasons we wanted to include the steering-by-wire technology on the RZ 450e is for the steering to be compatible with the improvement of the accelerator pedal’s dynamic response and the response of the car’s movements,” the American website Road & Track quotes Yushi Higashiyama of Lexus car company.
In aviation, the control-by-wire system was introduced in the 1960s, but in cars it was a side trend. “Citroën was the first to try to replace the mechanical link between the steering wheel and the steering wheel with a hydraulic one in 1970 on the SM model,” said the website Auto.cz.
According to him, the problem with electronic steering is that the driver has no feedback “from the wheels to the steering wheel”. Infiniti developers tried to solve this with feedback sensors.
Whether “control by wire” will become more widespread, or how quickly, remains to be seen. In general, it is believed that full electronic control will find its basis only with autonomous transport modules, whose mass deployment is still many years away from development.
It’s not just a stick. Tesla has started offering standard steering wheels again for the Model S and X