Systematically sort out the "skateboard chassis"

Rivian

Founded in the United States in 2009, it began to focus on the production of electric vehicles in 2011, and then lay dormant for a few years. After acquiring Mitsubishi Motors' manufacturing plant in Illinois in 2017, it began to attract market attention. Then in 2018, it announced the launch of two models, an electric pickup truck (it seems that Americans really like it) and an SUV. In 2019, Amazon ordered 100,000 electric delivery trucks from Rivian and subsequently invested in it. Since then, the company has entered the fast lane of development, and many car manufacturers and investment institutions have made strategic investments in it.

From the background of the founders, CEO RJ Scaringe founded the company after graduating from MIT with a Ph.D. in mechanical engineering, and is committed to electrification and zero carbon emissions. CSO Jiten Behl was a senior software engineer at Bosch and has extensive development experience, and CFO Ryan Green has worked in corporate finance for many companies.

So far, they have released two cars based on the same electric platform, one is the pickup truck R1T, and the other is the SUV R1S, both are based on the skateboard electric platform. Judging from the parameters and performance of the two cars, the size is actually quite similar, R1T is 5.5 meters, R1S is 5.1 meters, the battery life is the same, but the traction is different, which is probably due to the different motor selection.

Rivian says its vehicles can travel in water up to 1 meter deep.

Figure 15. Rivian chassis (from Baidu Image)

In fact, although most chassis or electric vehicles claim to be waterproof, no company has ever dared to let the vehicle drive in water 1m deep, which shows that the company has achieved a very high level of technology in the waterproofing of the chassis and electrical components in the car.

Next, let's take a closer look at the skateboard chassis. This chassis is the core of the company. It is equipped with a four-motor system and has a high degree of flexibility. At the same time, it is equipped with air suspension, LG Chem's 21700 battery cells + self-developed battery packs, battery management systems, etc.

The author found that companies like Tesla and Rivian, which are popular in the market, basically develop their own battery packs or battery peripheral designs. For example, Tesla has controlled battery costs to the extreme, while Rivian puts battery cells in its own battery packs and then encapsulates them in a carbon fiber chassis, focusing on waterproofing and weight reduction.

Because of these unique technologies, Ford and Cox Automotive have invested in Rivian and jointly developed new models with Rivian. At the same time, Amazon, as a major shareholder, gave Rivian a big gift package before its listing, claiming that Rivian will customize 100,000 electric vehicles for Amazon based on battery and skateboard chassis related technologies to assist freight services. I believe it will be easier to form economies of scale, and the overall growth rate may be faster than Tesla. Let us wait and see.

PIX

Next, let's talk about PIX Moving, a company that has been very popular in China recently. It focuses on the development of super chassis and integrates the control system, steering system, etc. into the chassis. Regardless of the size of the chassis, the components can be interchangeable, and the number of mechanized components is reduced, making the chassis structure smoother. At the same time, the super chassis adopts "software definition" and "universal modular flat chassis" to create a truly native smart car development model. All industries do not need to develop a whole vehicle from scratch. They only need to customize the upper application based on the universal chassis to quickly and flexibly develop smart cars for different purposes such as passenger cars, commercial vehicles, and special-purpose vehicles. This fundamentally changes the design and manufacturing process of cars and opens the "customization era" of smart cars.

It is reported that due to its modular architecture and autonomous driving system, PIX products are currently the company with the most coverage of scenarios in the world, involving 28 scenarios.

Figure 16. PIX model family (from the official website)

The official photo released by PIX is very shocking. It depicts a very good blueprint for using chassis of various specifications to build different models, from small to large, from low speed to high speed.

Figure 17. Schematic diagram of different tops on the same PIX chassis (from the official website)

We will not discuss the low-speed small chassis for now. Today we will mainly talk about the passenger cars, trucks and buses corresponding to its super chassis.

According to automobile theory, the idea is closer to one chassis corresponding to multiple superstructures, and different superstructures are used to adapt the same chassis. Different scenarios and theoretical loads will lead to different practical requirements for motor adaptation, suspension adaptation, brake adaptation, etc. In addition, the configuration of buses in low-speed scenarios and sedans + trucks in medium- and high-speed scenarios may also lead to some differences in the details of the entire chassis.

However, generally speaking, I think PIX has depicted the vision for future social travel, and then based on reality, it starts with low speed and low load, and after the technology accumulates or the market matures, it will gradually expand to high speed and heavy load. This is also a good strategy.

Of course, in addition to the above-mentioned representative companies, there are many similar companies that are also producing similar chassis with similar concepts, so I will not describe them in detail here.

4.3. Parts Suppliers

As electrification continues to deepen, international mainstream Tier 1 suppliers want to cover more business areas based on their expertise. In recent years, many companies have made some advance arrangements by investing in related companies or building their own teams, and then use these new products to obtain orders from car manufacturers or the favor of new scene parties. Next, we will take stock of the practices of these companies.

Schaeffler

Schaeffler is definitely the fastest-moving company. With the continuous deepening of new energy in recent years, Schaeffler has gradually felt the pressure of transformation. Traditional components are becoming less and less. If it does not expand in electric drive or new business, its future will become more and more difficult.

Based on this consideration, Schaeffler established the electric drive department in 2018, aiming to do more in new energy components, and launched the hybrid P2 module and electric drive axle. Speaking of this, don’t think it’s off topic. At that stage, it couldn’t make a skateboard chassis and didn’t know how to develop. It probably thought that wire control and three-electric components would be a core in the future, and Schaeffler’s technical reserves in this regard were not enough, so it started buying again.

In 2018, Schaeffler and Paravan established a joint venture to develop drive-by-wire technology and realize steer-by-wire. In the same year, it acquired Elmotes Statomat, which made up for the lack of original motor technology reserves. In this way, it launched the hub motor. At the same time, based on the hub motor, Schaeffler launched the concept of corner module, which is said to be designed for autonomous driving, and then launched the skateboard chassis (Rolling Chassis).

Figure 18. Schaeffler Rolling Chassis (from Baidu Image)

This product is designed with 4 corner modules (wheel hub motor + suspension integrated together) to make steering more flexible and 90-degree steering free. The middle battery is arranged in the chassis, which can adapt the battery life according to different scene requirements. The modular design of the chassis reserves space for the later reduction of the chassis size.

Figure 19. Rolling Chassis chassis module functional diagram (from promotional materials)

After the release of this product, on September 8, 2021, Schaeffler and Mobileye signed a strategic cooperation to combine Mobileye's autonomous driving technology with their own chassis to create a highly flexible and adaptable autonomous driving vehicle platform. At the same time, it has the necessary redundancy technology to meet automotive safety standards and can help autonomous driving solutions adapt to different scenarios and land quickly. It is reported that the product will be mass-produced in 2023. For parts suppliers, this time point is relatively easy to achieve, but it is also very fast. And the author believes that after the mass production of this product, the price of the entire skateboard chassis industry will be a butcher-like existence.

ZF

Speaking of ZF's skateboard chassis, it was also released very early. The earliest was at the 2018 CES exhibitor, the RINSPEED SNAP concept car, which used ZF's intelligent electric drive chassis (IDDC).

Figure 20. RINSPEED SNAP concept car and ZF's IDDC (from CES2018 data)

Although ZF did not provide much description of relevant information, the effect at that time was still very sensational. It created a chassis + scene-based superstructure, realizing all functions within the chassis to meet the needs of autonomous driving, making the superstructure easier to replace.

In fact, the core components of this IDDC are the EsayTum front axle and the mSTARS modular rear axle. The front axle is a modified electric power steering system that can increase the turning angle to 75 degrees (the traditional one is about 50 degrees), and the rear axle is actually an active rear-wheel steering system that can increase the maximum steering angle of the rear wheels to 14 degrees. But overall, there are no other highlights, and since that release, there has been no substantial progress in its implementation. I guess ZF will also think that the innovation is not strong enough and it is embarrassed to put it into mass production?