We took the double wishbone suspension in Argo and strategically built-upon and geometrically optimized it in every possible aspect. While Argo used a double wishbone suspension on all wheels, Brizo now uses a combination of a double wishbone suspension on the front and trailing arm on the rear. This simplifies the geometry and maintenance of the suspension. Additionally, the control arms are far lighter and stiffer as we no longer used standard metals and instead created carbon fiber control arms. 

The creation of this new and innovative suspension allowed students to gain design and manufacturing experience by using advanced CAD modeling such as skeleton modeling and making components by themselves using something as simple as a 3-axis CNC. The creation of this suspension not only allowed students to gain hands-on experience, but as we travel across the country, it will also ensure that Brizo is more nimble, rigid, and reliable. 

Whether Brizo is traveling cross-country or on the track, there are a multitude of different scenarios that can occur during a race, many of which are impossible to simulate during testing. Therefore, it is imperative that we have access to data from the car and the driver receives the right data at the right time as this is the key to success at competitions. This is all dependent on the steering wheel. The steering wheel is the main link between the driver and the rest of the car’s subsystems. When designing the steering wheel, it is essential that it contains all necessary inputs and outputs to and from the driver. We ensured that the driver would have access to everything needed without ever having to remove his or her hands from the wheel and attention from the road ahead.

Brizo’s steering wheel houses a lot of standard features such as cruise control, enabling of turn signal, headlights, and a horn. But we also implemented unique features specifically tailored for solar car racing. We’ve added a spring loaded thumb dial steering wheel, which allows the driver to  control the speed of the car on the steering wheel. The wheel also includes a seven-segment display to show the driver crucial information such as the current speed and battery voltages. We’ve also added an OLED character display on Brizo. This can be configured to display any data the race team is receiving from the car as well as messages sent straight from our strategy team via our telemetry application. For example, this message could notify the driver of our target cruising speed, or display vehicle warnings such as high battery temperature or low tire pressure. All of these innovative improvements allow the driver to make quick informed decisions while driving.

Brizo’s improved solar cell array utilizes the most efficient silicon cells on the market and is extremely thin, compact, and lightweight. The average solar panels have a 15% to 18% efficiency meaning that only 15% to 18% of sunlight’s energy is converted directly to electricity. Brizo’s innovative and top-of-the-line solar cells have an efficiency of over 25%. 

Not only is the array more efficient, but an extremely lightweight solar cell encapsulation results in a lighter, more nimble vehicle. Another area of improvement was strategically insetting the array into the body of Brizo, which is the process of creating a divot in the top shell of the car in which the array is placed. During this inset, we ensured that the angles were appropriate for sunlight to still reach the solar cells, but also significantly reduce aero drag on Brizo. Not accounting for the reduction in drag and weight saved, the improvement of the array efficiency results in Brizo gaining above a 4% power increase. All of these improvements allow Brizo to drive faster and further during races. 

The aerodynamic force on Brizo is almost non-existent. A jug of milk experiences more force from gravity, than the amount of drag Brizo experiences at cruising speed. In order to achieve this, the aero team performed a multitude of different software based aerodynamic testing and simulations such as airflow tuft and heat testing to design the most efficient bullet design.

When designing the top shell, we had to find the perfect balance between aerodynamics and many other design considerations that determined Brizo’s performance. The top shell is based off of a NACA 3405 airfoil which provides greater driver visibility and improved angles for the solar arrays. Unfortunately, these benefits are gained at the cost of less aerodynamic efficiency such as more lift, more drag, and less stability. When designing the aerodynamics and bodywork of Brizo, finding the ideal balance between aerodynamic efficiency and other design considerations is essential for Brizo to achieve optimal performance during races.