QUICKSHIFTING, BECAUSE EVERY MILLISECOND COUNTS

‘’To understand the intensity of driving an F1 car, you have to be in it. When you’re driving a 750hp machine at 200mph, the noise and the vibrations are incredible. The G-force when you take a big corner is like someone trying to rip your head off. You hit the brakes, and it feels as if the skin is being pulled off your body. You sweat so much during a race, you literally lose 3 liters of fluid. The adrenaline is such that your heart is beating 150 per minute. The experience is like nothing else on earth.”

Seeing the excited faces of drivers after the race, holding the trophy and celebrating their victory might make you think that they really must be having hell lot of fun driving the entire race. But alas, the driver, sitting in the cockpit comfortably, experiences such breathtaking moments that finally makes him the true possessor of the winning trophy. And what’s more than just sitting in the car and maneuvering through the tracks? It’s the whole lot of complex paddle and electronic control systems that the driver manages to operate in order to get the best performance out of the car and track. And do you think it’s easy to do so? Well, riding a streetcar and riding a formula-style race car are two poles apart, you may excel in the former but when it comes to the latter, you just can’t go with the traditional methods of gear shifting or clutch operating mechanisms because the race tracks are built for speed and quick response. If you fail to do so, you will have nothing more to see than a bunch of cars overtaking you and you’ll just disappoint your team then. The fast corners really demand a quick response from the driver, he must be able to exit the corner in the minimum possible time with the application of late brakes and electronic controls installed in the car. Afterall, every millisecond counts in the world of formula racing.

Now how do you really minimize the cornering time or accelerate fast enough through a straight track? Handling the steering wheel takes a lot of force and if you take your hand off to operate a manual clutch lever next to you in the middle of a turn, you’ll really lose a lot of time. Or, if you don’t properly operate the clutch pedal, chances are the wheels might skid through the track or worse than that, your engine might stall and then you’ll have very less control over the car. So it’s very crucial that you alleviate such mishaps by taking the help of electronic controls such as an electronic gear shifter and controls that let you make gear shifts just by the push of a button on the steering wheel. They save a great amount of time to your advantage. And if you are competing in a formula student competition, you’ll earn a lot of points due to the implementation of such technologies and if you make it to the dynamic events, you’ll earn points in the track races due to great acceleration capabilities and quicker gear shifts.

images (3)

All this sounds pretty amazing to implement in the car but when you really get to the core work, you’ll have to get your brain rats running like crazy to successfully get them installed and verified through test runs. And all this consumes time, a lot of time. Think about the idea, generate concepts for it, evaluate the concepts, make decisions, try them out and then keep iterating till you finally make it a success. The results are too rewarding though. The acceleration event gets you points if you’re able to finish the 75m straight track in the minimum possible time and if you have the launch control system in your car, you’ll get a good head start from standstill position. Also, in the autocross event which comprises of lots of tight corners and straight paths, flat shifting technique will save you time by allowing you to upshift without the use of clutch! Further, when on a straight track, automatic upshifting techniques will let you accelerate to the optimum level in each gear without the engine revving up too much and the tires skidding. Sounds too interesting. Now let’s get to the details to get a real taste of all these techniques.

There are broadly three types of quick shifting techniques that are electronically actuated and feasible: Ignition cut shifting or flat shifting, Automatic up-shifting and Launch control system. The implementation of all the three requires a very tedious work programming the ECU to get the right RPM limit where the shift will occur or the signal to shift the gear will be received from the driver.

IGNITION CUT SHIFTING or FLAT SHIFTING

In simple words, this gear shifting technique means to upshift by lowering down the engine RPM by cutting the ignition without the use of clutch and gas pedals. What’s interesting about this shifting method is that the driver doesn’t need to operate the clutch and gas pedals during the shifting process. The driver just makes a signal requesting for an upshift and then shifts the gear once the engine RPM drops to the required limit. This makes this technique faster to operate saving up the time that the driver would otherwise consume to work on the clutch and gas pedals. The basic working methodology behind cut shifting is that when you need to upshift, the engine RPM needs to get down. Now in a normal operation, you’ll let off the throttle, press the clutch, shift the gear and finally release the clutch. Just basic. But in cut shifting, the work of lowering the engine RPM is controlled by cutting out the ignition electronically. This in turn releases the load from the transmission and gear shifting becomes easier. Now, how long the ignition is cut depends on whether the duration is determined by the driver or until it has been detected that the next gear has been reached. It’s all programmed. There are factors beyond these but then, we don’t need to delve into the ECU programming for this. Overall, this is a very feasible method to upshift without the clutch and gas pedal actuation, unlike the traditional mechanical methods.

images (2).jpg

AUTOMATIC UP-SHIFT

This shifting technique is very rewarding when it comes to dynamic events like acceleration runs. What happens here is that a pre-determined RPM is set for each gear, an RPM at which the driver will get maximum acceleration from that particular gear. It often happens that revving up the engine beyond a certain limit gives too much traction to the wheels and they start skidding. So this limitation is overcome through this technique. The ECU will read the shift signal from the RPM sensor(tachometer) and automatically shift the gear up. This will aid in completing the acceleration run in lesser time than without it, since this run typically lasts for 5 seconds hence, points earned will be more by decreasing the time even a bit.

article_uw-sae-cal_05.jpg

LAUNCH CONTROL

This technique is basically to give a fast start to the car from a complete stop. The engine is allowed to rev up only upto a pre-determined level to gain the maximum traction for the best head start because as explained earlier, the wheels may skid if the engine revs up beyond a certain RPM. This also lets the driver hold the throttle fully open and gain an optimum start. This control is actuated by a button present on the steering wheel itself. When pressed, it will limit the engine RPM to that pre-determined level and when released, it will allow normal engine operation. This is too good a technique to be implemented during the acceleration event when the car starts from a complete stop position. Ultimately, too much of anything isn’t good. So even if you’ve got a powerful engine in your car, displaying its power won’t help you unless you respect the traction that the ground has to offer. The wheels will just spin helplessly and you will lose time recovering it.

So these are the three big technological implementations that can heavily reward the team with lots of points on the track if successfully installed by greatly minimizing the time to complete the track events. These help to resolve some big issues with the car like having to move the driver’s hands away from the steering wheel to shift gears and difficulty launching the car in acceleration event by revving the engine too much and skidding the wheels. The driver can actuate these controls by just the press of a button on the steering wheel. But though these ideas seem too promising, we can not ignore the cons just because we want more points anyway. Getting these successfully installed in the car is a great feat in itself since these are all electronically actuated and hence, attention to detail is a must when handling such kinds of stuff. In addition to this, lots of time is needed to verify these by test runs of the car and driver training too is equally important. The car may be well-built but needs an equally trained driver to operate all the functions within. However, innovation is what the formula SAE is all about, so this is highly valued by the judges who look for new technologies and it can earn the team valuable points. Finally, there must be a plan B for every decision, i.e., in case anything breaks down, the system should be repairable so that the team can return to the competition. Backups such as the existing gear shift lever will come to the rescue in such situations. Also, there must be enough room in the car for packaging things well. 100% safety must also be taken care of in case anything goes wrong. Rest all is just a hard-earned result of careful planning, hard work and proper time allotment for installation and testing of the car. Points will then just shower on the team.

images (4)

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s