Mass-produced steering-by-wire, what is it like to drive Tesla CyberTruck?

Recently, a video of the Optimus Prime robot holding a Thompson submachine gun to test the bulletproof performance of the Cybertruck went viral.

Although it was finally confirmed that the video was synthesized, Musk and many external bloggers also tested the bulletproof performance of CyberTruck. It seems that the stainless steel body can indeed withstand bullets.

In a country where gun ownership is legal, users buying a Taiwanese military-grade pickup truck can indeed handle a lot of things at home.

In addition to being able to carry guns, Tesla's pickup truck has also made many adjustments to its underlying architecture. The launch conference a few days ago was too short. Many fans said it was not enjoyable. They felt that Lao Ma talked too little. They hoped to explain the steering by wire, rear wheel steering and 48V in detail.

01. Steer-by-wire: easier to control in narrow spaces

Steer-by-Wire System is a new generation of steering system in which there is no direct mechanical connection between the steering wheel and the steering wheel, but is controlled through electronic signals.

The advantages of the steer-by-wire system are high flexibility, stable operation, real-time monitoring of system safety, and high efficiency:

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• High flexibility: Since there are no direct mechanical connections, it can be easily upgraded and retrofitted without changing the existing vehicle structure.

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• Good handling stability: The steering wheel is precisely controlled through the electronic control unit (ECU), which can better adapt to different driving environments and driving styles.

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• Strong safety: The ECU can monitor the driving status of the vehicle and the driver's steering operation in real time. Once an abnormality is discovered, corresponding measures can be taken immediately to improve the safety performance of the vehicle.

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• High efficiency: Since there is no direct mechanical connection, mechanical losses and friction losses can be reduced, improving vehicle economy.

In addition to these advantages, there are also the following advantages:

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• In line with first principles, the elimination of mechanically connected steering-by-wire can reduce the number of parts and costs;

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• It is in line with the development direction of autonomous driving and makes technical reserves for Robotaxi.

From this point of view, the steering-by-wire technology is indeed advanced. Does such a good technology have no other shortcomings?

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• High technical difficulty: The steering-by-wire system requires highly integrated electronic technology and advanced sensor technology, so its development and production are difficult.

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• The production cost is also relatively high, so it is still difficult to popularize the steering-by-wire system.

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• High dependence on power supply and electronic components: The steering-by-wire system requires stable power supply and reliable electronic components to ensure its normal operation. Once the power supply or electronic components fail, the steering system may fail.

Overall, steer-by-wire is a good thing, but it is difficult in terms of technology and cost.

Currently, the models on sale in China that use steer-by-wire include the top-end models of Infiniti Q50L, QX50 and Q60. The Toyota bZ4X model that will be mass-produced in 2022 will also be equipped with JTEKT's steer-by-wire with variable steering ratio. product.

Infiniti Q50's DAS steering-by-wire system has been criticized for a long time. Some users have reported that it is really difficult to use. The four-wheel alignment has to be done at a 4S shop, which is extremely expensive. In addition, this year's newly redesigned Lexus RZ cannot be driven on domestic roads due to regulatory reasons, with the steering-by-wire version and Mobius steering wheel.

It should be noted that steer-by-wire also provides favorable conditions for the promotion of special-shaped steering wheels.

Because the necessary condition for the special-shaped steering wheel to be available is variable-ratio electronic steering-by-wire, but the current steering-by-wire system does not meet domestic regulatory requirements, so the current special-shaped steering wheels are equipped with traditional steering systems, which poses greater safety risks.

Overall, steer-by-wire technology is still relatively niche. However, as relevant regulations are improved, domestic car companies should gradually follow suit.

YouTube blogger Marques Brownlee said that after CyberTruck adopts steer-by-wire and rear-wheel steering technology, the maximum steering angle can be controlled within 180 degrees, and the steering ratio is also variable.

Although it requires adaptation when turning, the operation is also relatively convenient, and the user does not need to rush to the direction.

And when driving at low speeds (below 40 mph), the Cybertruck's rear wheels can rotate up to 10° in the opposite direction, making the vehicle more agile at low speeds, especially when turning in parking lots.

At highway speeds above 40 mph, the rear wheels change 1 to 2 degrees in the same direction as the front wheels, providing more stable movement. This makes for smoother transitions between lanes, and the overall feel is like a longer wheelbase.

The CyberTruck's steering system makes maneuvering in tight spaces easier. Some users said being able to turn easily in tight parking lots made the big car feel smaller, improving driving convenience.

Overall, the CyberTruck's steering system makes driving more flexible and stable by adjusting the direction of the rear wheels at different angles at low and high speeds.

02.48V low-voltage architecture: Musk taught car companies a lesson

CyberTruck's low-voltage system also uses a 48V architecture instead of the commonly used 12V.

It is said that Musk also produced a booklet "How to Build a 48V Architecture Car" and gave it to many suppliers and car company executives. Ford CEO Jim Farley also received a copy.

Why is Musk so obsessed with 48V architecture?

Mainly because the 48V architecture has the following advantages over the 12V architecture:

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• Voltage increases, current decreases: 48V voltage is higher than 12V, which means using thinner wire harnesses or wire harnesses of other materials can reduce current heating and power loss. This reduces the size and wiring harness count of the vehicle's low-voltage system, thereby reducing costs.

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• Optimized wiring harness: Since the current required by the 48V system is reduced by 4 times, the power loss of the wiring harness will be reduced accordingly. This will save 16 times the power loss and further reduce costs.

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• Cost reduction effect: Tesla said that starting with Cybertruck, it will gradually shift to a 48V platform. Compared with the 12V low-voltage platform, the 48V voltage is increased and the current is reduced, which can reduce the heating of the wire harness. Thinner or other material wire harnesses can be used to reduce weight and cost.

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• Easy to implement: Switching to 48V means that the internal power supply isolation must be stricter, and the design of controllers and power supply systems that can support 48V will have a greater impact on circuit design, supplier supply, change management, etc. However, Tesla achieved this transformation by self-developing the entire vehicle controller, directly capping the self-development rate of the entire vehicle controller to 100% self-development.

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• Improve response speed: Tesla will design its own "electronic fuse" that combines fuse and relay functions. The response time will be increased to milliseconds and it will support firmware reset, which is the ability of OTA. This means that when faced with some emergency situations, the vehicle will respond faster and have greater processing capabilities.

To sum up, the CyberTruck 48V architecture has the advantages of increased voltage, reduced current, optimized wiring harness, cost reduction, ease of implementation, and improved response speed compared to the 12V architecture.

In addition to innovations in low-voltage systems, Cybertruck is also Tesla's first ultra-high-voltage model, using an 800V high-voltage architecture.

At present, many domestic Xpeng G6, G9 and Jikrypton 001 models also support 800V, but very few electric pickup trucks support 800V.

After CyberTruck uses the 800V architecture, it will bring the following benefits:

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• Reduce copper content in the entire vehicle: The 800V architecture can reduce the copper content in the CyberTruck and reduce the weight of the vehicle.

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• Improved performance and range: Reducing vehicle weight can improve vehicle performance and range.

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• Reducing costs: The 800V architecture can reduce the manufacturing cost of CyberTruck, thereby improving the vehicle’s cost performance.

In short, using the 800V architecture of CyberTruck will bring a series of benefits, including improving performance and endurance, reducing costs, etc.

From the perspective of the underlying architecture, steer-by-wire, rear-wheel steering, and 800V high-voltage architecture are not the latest technologies, but the great thing about CyberTruck is how to put these new technologies into the car and solve the subtle design and production problems. , while achieving cost reduction and efficiency improvement, allowing consumers to pay the bill. The biggest innovation lies in coordinating various suppliers to collaboratively solve 48V architecture problems.

At present, Cybertruck has started delivery, and more driving experience and technical details should be leaked in the future, and we will continue to analyze it at that time.