Tag Archives: vehicle dynamics

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Chalmers: Vehicle Dynamics

“A good car is not just a fast car… it is the one that goes the fastest around a corner.”  Praise Vehicle Dynamics!

Side note:

Chalmers has a lot of collaboration with industry on vehicle dynamics/autonomous driving. Chalmers also has a partnership with Stanford working on that autonomous Pike’s peak Audi TT. Super cool stuff! Professor Mathias Lidberg is the Chalmers man in charge.

Side note #2:

Colloquial: “Chalmers profs are super chill”. Professor Lidberg (well, we address him as Mathias) gave me a nickname “GoPro”, because I helped him with his GoPro video camera. Yep, he is also a fan of GoPro video camera. What a cool prof!

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Back to Vehicle Dynamics:

Sure, this course was quite challenging and somewhat essential to Automotive Engineering. The course studied basic vehicle-handling characteristics. What is …handling?

Motivation: have you ever sat in the back of a crappy minivan? If you have, then you might have some good clues why they are nicknamed “vomit comets”. When you come to a stop and your car is still wobbling up and down seconds after, it probably means you are driving a crappy car.

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How do we fix that?

The short answer is to study the car’s suspension geometry, springs and dampers – so they work with the rest of the car together in harmony.

We started modelling vehicles as a “bicycle” (if you think about it, cars are nothing but two bikes)… and we didn’t really go beyond the bicycle model either, because the model is so robust.

There was a lot of mathematics in this course. I had to dust off my Laplace transformation equations. Ok, I won’t go into the details about this course, as it will give me headaches. But here are some interesting thoughts…

1/ The Swedes here löv using LaTex for writing reports. And Yes, it looks super crisp!

2/ I mentioned that the Chalmers students are very proficient with Matlab. It is incredible how good they are! I still have a lot to catch up to them. Matlab is a handy tool to perform operations on large sets of data. Learn it before coming to Sweden.

3/ I described a study visit to the AstaZero test track. AstaZero is the world’s prime test ground for vehicle traffic safety. We were there to perform a few driving maneuverers, capture data, and…finally go home and analyse it. According to the data analysis, I am a jerky driver. Meh…

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I really enjoyed the course, as it was challenging, it had a mixture of theory and practically, and it had a very interesting hands-on lab project on the test track.

… but that exam was a little (too) difficult.

 

Så, exam season is upcoming. In fact I have an exam on Monday. Meanwhile, spring is in full swing. I am sitting on the grass, writing this blog…. Ummmm the grass isn’t completely dry…g2g!

 

Löv,

 

gimmygöteborg

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Ref:

Photos extracted from “Course compendium for MMF062”

This compendium also available as pdf file at

http://pingpong.chalmers.se/public/courseId/4042/lang-en/publicPage.do. © Copyright: Bengt Jacobson, Chalmers University of Technology

 

Below: my bike, beautiful in terms of vehicle dynamics in design.

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Vehicle Dynamics Test Track day @ AstaZERO

Long live SAAB! The fate of SAAB is an oscillating. It is a story frequently brought up by people in the automotive engineering/applied mechanics department. The company is flip-flopping between speculations of bankruptcy and restructuring. Many people around the world and in Sweden specially are sentimental towards the car that is “born from jets”. They are great cars!

The Automotive Engineering vehicle dynamics class had the joy of spending the day at the AstaZERO (Active Safety Test Area – Zero traffic accident) test track. It is a brand new testing facility opened in September 2014, and it is owned by TU Chalmers and SP (Technical Research Institute of Sweden). The track overview is shown above (sorry it is in Swedish).

testbana_2000[ref: http://www.nyteknik.se/tidningen/article3841629.ece]

The purpose of our visit was to conduct a vehicle dynamics lab in collaboration with NEV (National Electric Vehicle, the company that owns the SAAB cars brand). Yes, we got to drive SAAB test vehicles.

The goal of the lab is to help us develop a feel for complex vehicle behavior under motion. There were three tests: steady state cornering, frequency response, and accident avoidance maneuver.

DSC08127-001Steady state cornering: driving around a circle while increasing speed until the tires is starting to lose grip. The tarmac is wet and slippery. I think we got up to 65 km/h around a 14 m radius track before plowing wide.

Frequency response: practically doing slalom in a car to determine how responsive it is. Accident avoidance: at 60 km/h & try to avoid a “moose”. We had the chance to experience the difference ESP – Electronic Stability Control made in a car.

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(Photo: Moose avoidance test, source: http://www.crankandpiston.com)

 

There was no real moose fortunately, just a row of pylons.

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Video about AstaZero: