On April 20, Toyota's luxury brand Lexus exclusive pure electric model , the new RZ , was officially unveiled worldwide, and the new car is expected to be officially launched this year.
The RZ 450e debuted has a body size of 4805*1895*1635mm and a wheelbase of 2850mm. It uses a 150kW/80kW dual-motor system and is equipped with a 71.4kWh battery.
In addition to the DIRECT4 electronic dynamic four-wheel drive system, which can precisely control the power distribution between 0:100 and 100:0 in the front and rear wheels, the RZ is most notable for the official installation of LEXUS's first Steel by Wire variable ratio electronic steering system (hereinafter referred to as StrBW) and a special-shaped steering wheel.
1
Toyota's pure electric series may feature the special-shaped steering wheel as its distinctive symbol
StrBW replaces mechanical connections with electronic signal control, enabling electronic data exchange of steering and road surface information between the wheels and the special-shaped steering wheel. The maximum steering wheel rotation angle of the system is set at about 150 degrees on the left and right, but the steering wheel is not as sensitive as imagined, and the slight rotation will not have a direct reaction, although the steering range is only the traditional steering wheel or , but it is easy to get started, which will greatly reduce the driver's operating amplitude, in the steering, U-turn, parking, winding road and other driving situations do not need to cross the hand to turn the steering wheel.
With no physical connection, less excess vibration from the tires and brakes, and only important driving information such as road conditions fed back to the driver, StrBW can also optimize the steering gear ratio based on specific vehicle conditions, giving the driver more confidence. In addition, without the upper part of the steering wheel to block the line of sight, the position of the dashboard can also be reduced, so that the driver can be more focused, thus creating a driving experience that integrates people and vehicles.
The production version of the bZ4X (bottom) is highly restored to the concept car (top), but the special-shaped steering wheel has become an option
Steer-by-wire and the special-shaped steering wheel have actually appeared on the Toyota pure electric model bZ4X concept car released last year, but the traditional circular steering wheel is still used on the bZ4X mass production model, but the car manufacturer also said that some models can be equipped with a special-shaped steering wheel.
We have also asked how much money is required for bZ4X optional steering-by-wire steering and special-shaped steering wheel, and the result is that the response of the relevant personnel is "tens of thousands", which makes us a little surprised, and the set of things that are steered by wire and the special-shaped steering wheel is much more expensive than imagined, which shows that its cost and technical content are still not low.
Lexus RZ should not have too much cost concerns, there is a high probability that in the mass production model will have a model equipped with StrBW and a special-shaped steering wheel, and it may be the standard of the whole series, and even in the future, Toyota's pure electric series may use the special-shaped steering wheel as its significant symbol.
The benefits of the special-shaped steering wheel are obvious, just from the shape point of view, the lower part of the steering wheel can provide more driver legroom, increased comfort and ease of access, while the upper part of the steering wheel without obstructions gives the driver better vision. Even since there are only 3 and 9 o'clock positions to hold, this helps to develop good driving habits and so on. However, the special-shaped steering wheel must also be supported by a variable-ratio electronic steering system like StrBW, otherwise it will be useless and even increase the danger of driving.
2
The difficult-to-use yoke steering wheel has led to a decline in Tesla brand ratings
In January last year, Tesla announced that it would "redefine the steering wheel", and the new Model S decisively introduced a special-shaped yoke steering wheel called "Yoke", and Musk also said smugly: "I have been driving with the yoke steering wheel for a while, which is great in my opinion." Subsequent new cars such as the Model X, Cybertruck and Roadster will all use the Yoke steering wheel.
Unfortunately, the well-known American magazine "Consumer Report" does not think so, they commented after actually test driving the Model S: "The Yoke steering wheel has no special advantages (only a wider field of view), and there may be safety concerns (the special-shaped design is not conducive to the action of turning, and the driver cannot accurately grasp the steering wheel when turning). ”
The key reason is that Tesla's steering wheel has an empty appearance, but there is no variable ratio of progressive steering or steer-by-wire steering technology support, resulting in many car owners are very uncomfortable after contacting new cars, especially when parking at low speeds, it is even more busy. More car owners complained that they should be very careful when driving the Model S in the icy section, and it is almost impossible to do some quick actions to save the car.
For this design flaw, someone asked Musk if he would introduce a traditional steering wheel later, but Musk said: "No." He also once said: "Progressive steering requires complex transmissions or drive-by-wire systems without direct mechanical connections, which are expected to be achieved in a few years." "It means to make it up first."
What about consumers who have already bought a new Model S? T Sportline, one of Tesla's tuners, rushed to the rescue (shou) field (ge), announced that it would provide a better D-shaped steering wheel for the new Model S, with three steering wheels of 2299-3499 US dollars (about 1.48-226 million yuan) to choose from, which was still in short supply for a while.
In the latest car brand rating released by Consumer Reports, Tesla's rating dropped 7 places to 23rd, which is Tesla's worst performance in 7 years. Consumers report that the difficult-to-use yoke steering wheel is the main reason for Tesla's decline in rankings.
In the matter of carrying the special-shaped steering wheel, Toyota once again showed its deep technical heritage, the complete set of technology is perfect and mature, and Tesla is a bit stretched. Looking at the sloppy workmanship of Tesla vehicles, the batteries that are constantly on fire, the automatic driving that is not working at all times, etc., there are still many places where Tesla needs to learn from Toyota on the road of car building.
3
Steer-by-wire places very high demands on the reliability of electronic devices
As a new next-generation car steering technology, steer-by-wire is an important part of the autonomous driving of future cars. However, it should also be noted that since there is no mechanical connection between the steering wheel and the tire, the number of rotations is completely determined by the electronic control unit of the ECU, which has very high requirements for the reliability of electronic equipment.
The earliest production car equipped with steer-by-wire technology was the Infiniti Q50.
The 2013 Infiniti Q50 first applied direct adaptive steering, but was recalled in 2016 for reasons that the system control unit could cause differences in the steering wheel and wheel rotation angles. Strictly speaking, Infiniti's DAS is not a simple steer-by-wire, because the system retains a mechanical connection, and the intermediate clutch will automatically close when the power is cut off, so even if the DAS system fails, the driver can drive the vehicle normally. This was because regulations at the time did not allow the steering wheel to be separated from the mechanical connection.
With the improvement of the reliability of electronic equipment in recent years, the research and development of technology related to steer-by-wire and the formulation of regulations are being carried out simultaneously. Many foreign markets have relaxed the relevant regulatory restrictions on the steer-by-wire to the car, allowing the on-wire steering to mass production. The Chinese steering standard GB 17675-2021, which came into effect in January 2022, also lifts previous restrictions on steering system steering wheel and wheel object understanding. It is believed that in the future, the steering wheel with steering by wire on the car will become more and more common, and the era of redefining the steering wheel will come quickly.
Statement | Kano
(This article is the author's personal opinion only and does not represent the position of DearAuto.) )
———— END ————
law
law
look at
ask
Mr. Li Guoyong of Guangdong Green Law Firm