Chapter 205 Laser Scanning

Orlando. Bohr, the head of the MIT Mobile Robotics Laboratory, was established to study a field robot that can adapt to the complex terrain and environment of aliens, such as participating in NASA's lunar or Mars exploration program.

The robot brought by Orlando this time, called "Walker", has a tracked transmission mechanism and a humanoid shape. This time, they broke through the previous constraint of using remote control and directly introduced the latest research results of the MIT Artificial Intelligence Laboratory, which allows the "Walker" to identify autonomously. Terrain, and choose to pass.

This time, the competition between Orlando and his brother Mark is to see who is the first to cross the randomly arranged terrain of the robot invented by both sides.

Both sides are very confident in their works.

When Orlando learned that Mark's robot was the seven or eight toy cars placed on the ground, he suddenly felt that the other party was a little disrespectful to this competition and took this competition as a joke.

Before that, "Life Survival Laboratory" and "Mobile Robot Laboratory..." had gone through many competitions, but the results of the competition made Orlando a little ashamed. The robots that spent millions of dollars in their laboratory develop were not as good as Mark's second-hand parts and abandoned by them. The equipment assembled is not like a monster.

Although Lin Hong also understood the basic operation principle of Mark's toy cars, he did not understand what kind of medicine was sold in Mark's gourd, and why he was so confident in this competition. But intuitively, he felt that there must be something else he didn't understand.

The robots brought by Orlando are quite shocking to everyone, and they are very full of science fiction elements. In terms of performance and appearance, they are better than Mark's toy car.

Arthur and Vina must be faithfully on the side of Orlando, thinking that Orlando will definitely win this time.

"Well, hurry up. It's getting late now. We have finished the test, and I have to perform for my fans."

Seeing the notebook computer in the hand of the "Walker", Mark also felt a little pressure. He didn't know what the group of crazy people at the Massachusetts Institute of Technology had developed. Although they were not very good at making machinery, they were really good at computers and had always been at the forefront of the world. .

However, it's time to do it now, and it's useless to worry. Is it really as powerful as Orlando said? Why don't you just take it out and have a try?

"Honey, come on!"

"Dad, come on!"

Vena and Arthur cheered up Orlando next to him, which made Mark a little depressed. If he had known that he had also found several cheerleaders to cheer.

"Mark, all your toy cars are participating in the competition?"

When Orlando saw Mark placing a total of eight toy cars on the starting line at the same time, he couldn't help asking.

"Of course, what's the problem? There is no prescribed quantity before.

"State in advance that you can't use the remote control. This is the rule!"

"Of course. That's what I want to tell you."

Seeing that Mark seemed to be very confident, Orlando looked back at the obstacles on the field. In doubt, he went to the center of the field and moved some of the obstacles again.

"You suspect that I cheat!" Mark said dissatisfiedly.

"For the sake of fairness, you know."

Both sides reiterated the rules of the game again. After the start of the game, they are not allowed to control the robot or the car, otherwise they will lose. Whoever crosses the obstacle to the opposite side first wins.

As before, Vina is in charge of the judge.

After Mark and Orlando checked the machine for the last time, Vina blew the whistle.

The competition officially begins!

Due to its small size and light weight, Mark's toy car starts first, and runs slowly to the front at the same time. The speed is not fast. This is mainly considering that the front may encounter obstacles. Although elastic anti-collision devices have been added to the front and back of the car, if the speed is too fast, it will still damage Of.

The "Walker" robot also began to start slowly. The tracked stepping method was very smooth, and the sound of creaking gears turning was also very pleasant. Its speed is not fast. As we all know, the initial speed does not mean anything. The most difficult thing is that you will encounter obstacles along the way. How to avoid these obstacles is the top priority.

Lin Hong noticed that one of the eight cars soon touched the first obstacle. After a slight collision, the two cars next to him immediately had a chain action. One of them turned to the right, and the other began to turn to the left. After walking for a while, he readjusted the original direction to continue. Move forward.

Lin Hong knows that this is the chip in the car that works again. When the car collided with an obstacle, it immediately triggered its signal sending mechanism. With the left and right swing of its top sensor, like other cars around it sent instructions with obstacles here. So after receiving this command, the other two cars immediately performed the preset excitation action and immediately began to turn. Bend to avoid.

However, as these cars encountered obstacles one after another, the mechanism began to become chaotic. The eight-two cars completely lost their sense of direction and began to move around the field. One of them even fell directly and came back to the original way, but halfway there was no sense that other cars were holding. The signal continued, so it immediately turned around and drove in the opposite direction.

This is also a simple judgment mechanism.

Lin Hong has read the core code of these cars, and there is nothing more than three very simple conditions.

If you encounter obstacles, notify other cars to turn.

If you don't receive the synchronous connection signal of other cars within a certain period of time, then turn around.

If you receive an obstacle signal from another car, then adjust your posture after turning.

These are just three very simple LF-THEN statements, which are the most common sentence patterns in programming, and nothing special.

Orlando's "Walker" seemed to be very calm. He slowly pushed forward. When he was about to approach the first obstacle, he stopped and his head began to turn.

"Dad, what is it doing?" Arthur, who had been following it, said strangely.

"It's scanning the terrain." Orlando laughed and said, "In its eyes, there is a 2D lidar scanner that can scan the terrain it sees into the computer, and then build a corresponding model in the computer to calculate the next path."

"It's so cool!"

Arthur walked to the "Walker" and looked sideways at the notebook display in his hand. Sure enough, he saw that in the display, the 3D model of the iron barrel in front of it appeared on it. In addition, the models of other obstacles also emerged from left to right step by step.

"It's so powerful!" Arthur screamed.

Lin Hong heard the words and walked over to have a look, and was immediately suppressed by the picture above.

It's too powerful to use the laser directly to build a 3D model of the thing in front of it in the calculator!

What is the principle of this?

Lin Hong's brain runs rapidly, thinking about possible ways to achieve it.

After thinking for a while, Lin Hong asked the first question: "UNCLE (Uncle), lasers are generally dot-shaped. If you rotate like this, you can only scan at most one section. How can you scan the vertical picture?"

Orlando looked at Lin Hong with some surprise and was a little surprised. He didn't expect him to ask a quite level question so soon.

He explained: "The output mode of the lidar laser has been transformed from a single-beam point laser to a linear laser, so that the 3D picture can be scanned by rotation. The scanner obtains the data of a scanned cross-section at one time by measuring the reflection of this beam of linear light on the target object to be tested. The advantage of this is that the scanning speed can be very fast and the accuracy is relatively high. The disadvantage is that the laser becomes a line segment, and its strength will greatly attenuate with the distance, so the ranging range is very limited. For ranging scanning at close range, such as less than ten meters, it is enough to meet the demand.

Mark, who ran over immediately after hearing Arthur's screams, was shocked when he heard his words.

"I didn't expect that your school's artificial intelligence laboratory really made something more interesting." He said.

"By what principle does it measure the distance?" Lin Hong asked the second question, "Is it reflected by laser?"

"Yes." ORLAND NOD, "STONE, YOU ARE A THINKING CHILD."

After praising Lin Hong, he continued: "This is the principle of triangular ranging based on laser. The other eye of the rambler is the camera, which is responsible for capturing the reflected laser. According to the principle of reflection, an isosceles triangle is formed between the laser, the camera and the object. The height of this isosceles triangle is the distance between the object and the walker. It is very easy to use the trigonometric function formula. Calculate it."

When he explained, a picture gradually appeared in Lin Hong's mind. The three components were abstracted into three points, forming a triangle. He easily understood the principle of it.

"Of course, this is the most ideal situation." Orlando continued to explain, "Now we are not in a completely dark environment. There are many interference light sources around us, such as the incandescent lamp overhead, which will interfere with the camera, so the principle of light source filtering and laser extraction algorithm is more complicated..."

"Hey hey, don't be happy too early. Although your rambler sounds very powerful, his speed seems to be a little slow. When it models all the obstacles, maybe my children have reached their destination!"

Mark is still optimistic, because although his toy car group has been in a chaotic state, it is at least pushing forward step by step, while the "walker" keeps modeling the environment. After calculating the strength of the road, it moves forward a few meters, close to the new After the obstacle, it will stop again for scanning.