## Chapter 1 : Travelling is like a Kalman filter.

If you know what a Kalman filter is, skip to the next chapter, or just read on to make sure I did not make any mistakes. A Kalman filter is an algorithm which uses series of observations over time to estimate unknown quantities. A simple example is of a robot trying to figure out where it is. The robot has a bunch of sensors which give it information about how far a certain obstacle is, or how fast the robot is going. The algorithm uses these observations to estimate the speed and the location of the robot, and then predict what the location and speed would be at the next time step. It then observes the surrounding again, and compare the sensor readings with its predictions. This way, it can then refine its priorities to different sensors, and predict to a higher degree of certainty where the robot it. Simple, right? 🙂

You may be thinking: “Why do we need Kalman filter to tell us the speed when some sensor on the robot is capable of doing so?”. This is because all sensors have an error associated with its reading, and these errors can be baaaad. The awesome thing about Kalman filter is that regardless of how accurate it is, the more data you have, the better its prediction would be, and this is where traveling comes into play.

## Chapter 2: Be ready to have shit loads of half-naked old chinese men eating smelly food.

I love travelling, and for me the best part of travelling is that regardless of whether your experience is good or bad, it makes you a better person. This is essentially why I compared  travel to Kalman filter. The more data you have, the better. It is with this attitude that I start all my travels, and my trip to Wuhan was no different.

For 21 days in July, I went to Wuhan University in Wuhan on an academic trip. During this trip,  I presented my academic research to numerous professors and students; collaborated on some projects with some professors and students; and helped others with fixing their work. I also got some time to work on my thesis.

However, when I was getting ready for Wuhan, I was expecting the worst. This was partly due to the stories I had heard from my friends who travelled through China two years ago, and as such I came prepared with loads of mosquito repellent, disinfectant towels and way too much toilet paper. All, very unnecessary in retrospect.

## Chapter 3: And I was thinking to myself, “This could be Heaven or this could be Hell”

Turned out to both if I am completely honest. We ended up staying in a hotel rather than the “guesthouse” we were told to expect. I had a shared room, with two Ethernet ports, and a TV with 40 Chinese TV channels. The breakfast was included, and there was daily room makeup service. The swimming pool and the spa were non-existent, no-one spoke a single word of English and I was “checkout” of my room two times during the 20 days. There was no laundry service, credit cards were not accepted and there was no WiFi. The name of the hotel is Junyue Holiday Inn.

## Chapter 4: “improve oneself, promote perseverance, seek truth and make innovations”

Overall the trip has been wonderful, far better than I expected and most of the credit for that goes to the wonderful people at Wuhan University, especially Chen Long and Professor Li. Not only were they our de-facto translators, but the university paid for almost all of our lunches, as well as for a few other things (such as our Chinese telephone numbers). In the end, the work was quite enjoyable, and it was, especially for myself, a crash course into how research presentations usually are. Even though we changed offices 6 times during the three weeks, all the places were air-conditioned and very comfortable to work in.

The main project I was working on was a Dynamic SLAM implementation for Slam6D software. I also gave a few presentations introducing the Chinese professors and students to open source software that we use at our university, such as ROS, OpenCV, PCL, etc.

## Chapter 5: In China They Eat Dogs (Danish: I Kina Spiser de Hunde)

Food was another thing I was worried about before the trip. So much so that I took 5-6 packets of noodles with me to China from Germany, with the intention of buying a water heater and eat noodles during my stay there. Despite still not knowing most of what I ended up eating, I actually enjoyed the food quite a lot. Luckily, I was introduced to proper technique of using chopsticks not too long ago, otherwise I probably would have struggled a bit. 🙂

As bad as the hotel was in many regards, one awesome thing about it was the fresh hot dry noodles they had to offer during breakfast. Hot dry noodles are a very traditional to Wuhan. These are noodles which have been fried and are then boiled again before being eaten. These are traditionally eaten with peanut oil and sesame paste, but my addition of Encona hot sauce made its so much better. 🙂

## Chapter 6: “No nice men are good at getting taxis.”

It has been 12 days since I am back, and the thing I miss the most are the cheap cheap cheap taxi cabs of China. As good as the public transport is in Germany, nothing beats the freedom of going out of the hotel, getting a cab, and going to your destination. No long delays, no waiting, no walks. Though the waiting part is not entirely true, since often there were not as many taxis arriving as there were guests waiting. This is where the only way to get a cab was to go somewhere else to find a good stop, or start pushing people out-of-the-way. 🙂

## Chapter 7: Fun fun fun…

The trip to China has re-calibrated my scale of large cities. Wuhan is huge, something I discovered during the ride from the airport to the hotel. It took us about an hour of driving with-in the city to reach the hotel, which was only in the center of the city. Imagine going from one end of the city to another…

And as any big city, there was a lot of stuff to do in the city. A lot of fun touristy stuff. The most famous among these is the Yellow crane tower and the snake park. This is a building which is supposed to be 2000 years old, but as I found out afterwards, it was rebuilt only 30 years ago based on a 2000 year old design. It offers a wonderful 360 degree view of the city seen below:

Another significant location is the bridge which can be seen in the image above. It offers nice night views of the city, and of people swimming in the river :). Crossing the bridge one can either go to the Guiyuan Buddhist Temple which has amazing buddha statue, and large numerous turtles; or the wonderful park along the river which features very weird and random statues. Another cool place near-by is the Wuhan Zoo, which features a show of bicycle riding, rope walking bears, horse riding monkeys and ring jumping tigers.

My hotel was near a body of water called East lake, and as such I ended up going to numerous places of interest along the lake. These include Hubei Museum, a water park, an amusement park, the Wuhan sea world, and a round-about called Guanggu Circle shown below. Another place which is recommended is the hiking trek around Mo Mountain, even though I did not end up going there.

Other places worth visiting are Hubu Alley which is the Wuhan food street with huge variety of snacks and Jianghan Road which has thousand of street vendors selling all imaginable products.

## Chapter 8: Pizza Hut closes at 9 pm

I finally came back to Germany on the first August. It has been a busy month and hence, just posting this. Partly, because my time in China was not as productive regarding my thesis as I had expected. Nevertheless, it was a very fun and informative. I learned a lot about how other researches treat you, and about research presentations. I learned how collaboration really works across borders and fields. In the end I has an awesome time in China, meeting numerous Chinese people who did not speak any English, but tried nevertheless. And now I am back in Bremen… where Pizza hut closes at 9 pm…