Water Magician

Chapter 307: Target ZMP Control

Editor: Tseirp

The next morning.

The Kingdom delegation gathered in the dining hall of their quarters, where they were informed of a shocking revelation.

“...We’re leaving today?”

Ryo’s expression at that time could be described as ‘shocked’.

“The tide seems to have subsided, so we are leaving today. Apparently, the ships are quite huge and only two can dock alongside the pier at a time. As usual, the Empire goes first, then the Union, followed by the Kingdom. The Empire has already started boarding. Meaning, we board in two hours. So get ready.”

Most of the delegation members nodded to the words of Commander Hugh McGrath.

Except for a certain water-attribute magician who didn’t....

“The second day of the scheduled golem tour...”

“No, there wasn’t even one to begin with.”

Hugh quipped at Ryo’s lament.

The Duchy permitted a visit only for two hours on one day.

The fact that they granted permission to an outsider from another country was unusual in itself....

“Listen Ryo, the golem of the Van De Vie Theocracy that we are heading to now is touted as the best in the Western Countries, right? Don’t you want to see those as soon as possible?”

“Makes sense! You’re certainly right Etho, I should focus on the bigger picture. Okay everyone, let’s hurry up and get ready!”

Ryo did a 180-degree turn from Priest Etho’s words.

As expected, the members of ‘Room 10’ who have known Ryo for a long time seem to know how to handle him....

Needless to say, Commander Hugh McGrath was speechless....

Two hours later.

There are two ports on the Aus River, and the one with the mission ships is the port dedicated to the castle.

Therefore, it is located adjacent to the castle.

Two huge ships with double decks were docked at the dedicated port.

Carriages and heavy cargo were to go on the lower deck, and people were to ride on the upper deck.

“It’s quite huge...”

“I feel like it would tip over if it were at sea...”

“I heard it’s only meant for the Aus River.”

“Though not as cool as the ship we saw in Whitnash.”

Those were Amon, Ryo, Etho, and Niels’ impressions.

The last line may sound like Ryo, but it was Niels.

Even Niels, who is considered to have no sense of aesthetics, still thinks the Trimaran ‘Rain Shooter’, which he once saw in Whitnash, is beautiful.

Incidentally, those four did not know the current whereabouts of the Rain Shooter....

When they had finished loading the ship with the many cargoes and nearly thirty carriages that had been supplied by the QC Duchy, a commotion broke out.

“Kyaaaaaahhh!”

A scream echoed from the castle.

It wasn’t just the one.

They could hear a couple of enraged screams as well.

Of the three hundred members of the Kingdom delegation, hundred were civilian officials, but the remaining two hundred were adventurers.

D-rank and above adventurers no less.

Naturally, they were able to act almost reflexively in response to the occurrence of an abnormal situation.

Party members immediately gathered together and exchanged eye contact.

At about the same time, Hugh McGrath, the leader of the delegation and a former A-rank adventurer, gave the order:

“Civil officers, board the ship post-haste. D-rank parties should also board their allotted ships and wait on board, Protect the civilian officials should things go south. B- and C-rank parties are to stay ashore and be ready for battle.”

It was obvious that something unusual had occurred in the castle...but they couldn’t be rash in their decisions since they had no idea what it was.

What happened?

It didn’t take long for the Kingdom delegation to find out what it was about.

“I can hear sounds... approaching.”

“It sounds heavy.”

“It has to be that thing...”

Amon muttered, Etho added, and Niels imagined.

There was a wall between the castle and the private port.

The wall collapsed in an instant.

What emerged was, as one might imagine... a golem.

And not just one.

The walls collapsed one after another, and from the collapsed areas, a dozen golems, at least that they could see, headed toward the group.

“Uraaaaaaahhhh!”

Then, one of them charged forward raising a battle cry.

Swordsman Harold from ‘Room 11’.

“Wha? You dumbass!”

Niels shouted, but it was too late.

Harold came into contact with the lead golem, and he slammed his sword into its leg with a sideways cleave.

Clang.

Along with a high-pitch sound, Harold’s sword was repelled.

Not a scratch on the golem’s leg.

Harold was downright stupefied.

Surprised, he quickly stepped back to keep his distance...but the golem swept its four-meter halberd horizontally as it stepped forward at a speed that one couldn’t possibly imagine from such a huge body.

Harold managed to put his sword between the approaching halberd and his body, but....

It was a feat of inhuman physical strength.

“! ”

Harold was blown away as he let out a cry.

Like a batter hitting a ball in baseball...Harold was blown away...like the ball.

The Kingdom delegation watched the whole scenario with stunned expressions.

“Come to think of it, back then in the Inbury Duchy, Ra was sent flying just like that...”

Ryo felt nostalgic as he recalled the scene he once saw.

And neither would a thrust from a spear penetrate the little gap in the neck.

If so, it would be most rational to stab it after tipping it over....

Take an ogre for example, one way to finish it off would be to crush its legs and knees, and then cut off its head when it falls.

In the first place, though, the position of the head feels totally different, even physically, between an agre, which is usually hunched over, and a golem with good posture.

Hence why Ryo chose the method of tipping it over.

The key to this was....

“Target ZMP control is an absolutely inevitable concept when building a biped robot.”

In a biped robot, the point where the combined forces of gravity and inertia intersect with the ground is called the Zero Moment Point (ZMP)... granted, it’s a little difficult to understand.

Literally, it is the point where the moment of total inertial force is zero... that doesn’t make it any clearer either.

First, we’ll briefly look into the term ‘inertia force’.

It is a little different from ‘inertia’. Though different, it’s not difficult to understand because we all experience it often.

For example, when riding a train or a car, you may have experienced a ‘whoa’ moment, being pulled in the direction opposite to the direction of travel the moment the train or car departs.

That force pulling in the opposite direction is ‘inertial force’.

It’s nothing difficult.

With that in mind, let’s consider the zero moment point using people walking and running as an example.

When walking slowly.

The force of ‘gravity’ is applied directly downward, and the ‘inertial force’ is applied in the opposite direction, that is, backward.

The ‘resultant force’ of these two forces is the ‘total inertial force’.

This is the same force that we learned about in junior high school science class, where the arrows of the two forces are combined to form a parallelogram.

When walking, the inertial force applied backward is small, so the parallelogram becomes a long and narrow rectangle.

Now let’s look at when running.

‘Gravity’ is still applied directly downward, but the backward ‘inertial force’ is greater.

In other words, the parallelogram (in this case, a rectangle) is not long and narrow, but has a large area.

As a result, the ‘total inertial force’ is shifted considerably backward.

Gravity is constant.

Inertial force can be controlled by adjusting velocity.

If just the right inertial force is called target inertial force,

The resultant force of gravity and target inertial force can be called target total inertial force.

The ‘intersection point between the line of action and the ground’, where this target total inertial force is extended, is the target ZMP.

The robot’s attitude control must be considered while keeping in mind where the target ZMP is to be placed.

“Aibo, the automobile company, realized bipedal walking by using three attitude controls: Target ZMP Control, Floor Reaction Force Control, and Landing Position Control.”

Ryo muttered as he looked down at the fallen eleventh golem.

It seemed to be knowledge he had learned back on Earth.

Looking at it, it seems impossible to grasp....

The movement itself is not difficult, considering what humans normally do.

For instance, say you stumble on a bump on the ground while walking.

Naturally, you would fall forward.

At that moment, how does one move to prevent from falling over?

Step forward using the other foot.

Doing that prevents one from falling.

By having knowledge of the Target ZMP Control, even a biped robot can do that.

And in the case of the golems of the QC Duchy this time, when it was stabbed by Ryo from behind, it did not prevent itself from falling by taking a large step forward... meaning, Ryo was trying to prove that the Target ZMP Control was no good.

To prevent from falling, one would have to take a large ‘forward’ step, but the answer lies in the ZMP that occurs ‘backward’....

It is not complicated once you get the hang of it, but a complex one if you don’t.

Ryo’s golems for paddy field management in the Rondo Duchy were not to his satisfaction.

Nevertheless, the only thing that was excellently done was concerning attitude control to let them work in that sorry excuse of a paddy field.

Compared to those, the golem lying in front of him seemed to have poor attitude control....

“That said, it should be worth studying.”

Saying this, he first detached the head completely.

Then, from the neck, he took a closer look at the chest armor and the back armor.

There must be a mechanism or method to remove the armor somewhere, he thought.

Otherwise, it would be impossible to maintain it....

On the battlefield, or when showing it to people from other countries, it may appear fully protected, but the armor would need to be removed when serviced, he thought.

The experience he had gained from tinkering with captured Union artificial golems under Kenneth’s supervision was put to good use there.

After fiddling with it for a while, he found it.

“Heave.”

Even though it was unnecessary, with a shout, he undid the inner clasp, and the chest armor came off.

“One more, heave.”

Shouting further, though again unnecessary, he undid the inner clasps, and the back armor came off as well.

Once the initial starting point was found, the rest went relatively smoothly.

The arms, legs, hips, and so on, were built according to the same design concept.

And within five minutes, almost all of the armor was removed, revealing a naked golem...minus the severed head, of course.

But then Ryo suddenly came to his senses.

He remembered where he was.

His comrades were still fighting.

“Oh shit...”

He realized that it was indeed a fatal screw-up to leave his comrades hanging in the middle of a battle and try to pursue his hobby.

He looked up and saw Master McGrath, the leader.

He had seen Ryo topple the eleventh one and drove his sword through its neck.

While giving instructions, he joined in the fight himself.

He watched for a golem fighting using its legs to come forward at the right moment, poked it from behind to knock it down, and when it was down, he put his sword through its neck.

Although not as sophisticated as Master McGrath’s, all ten remaining golems were taken down, mainly by the B-rank parties.

In the end, a total of ten golems were defeated with zero fatalities.

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