Chapter 274: Design difficulties

A set of samples was made and naturally tested. Because the old work clothes of his father were used, Chen Xin also invited his father to help him test.
However, Chen Xin's father was not satisfied with the exoskeleton protective suit made by Chen Xin.
"I can't move my steps, I can't lift my hands, it's not suitable for doing things." Chen Xin's father put on this exoskeleton protective suit, and after moving his body, he gave his opinion: "And this helmet is made of It’s too big and inconvenient."
"Are there so many questions?" Chen Xin was a little surprised when faced with his father's evaluation of the finished product.
Chen Xin's father wanted to remove the helmet from his head, but because of the joint structure of the exoskeleton, he could not bend his arm more than ninety degrees, so Chen Xin had to help remove the helmet.
Chen Xin's father, who took off the helmet, said to Chen Xin: "You have to take the helmet off with the help of someone else. How can your design be okay? The exoskeleton must at least ensure the normal activities of the human body and not cause obstacles."
"Then I will adjust it. It should be a problem with the joint connection structure." Chen Xin listened modestly to the advice given by his father, and he had already seen the problems.
Because of cost concerns, Chen Xin adopted a relatively simple design for the structure of the exoskeleton. However, it is clear that this overly improvised design makes this exoskeleton greatly compromised in flexibility, and it cannot even meet actual needs.
Helping his father to remove the exoskeleton from his body, Chen Xin asked his father again: "Dad, how does it work for protection?"
"It's a bit heavy, but fortunately, it's almost the same as wearing a cotton jacket." Chen Xin's father opened the zipper of the protective suit and took it off: "It feels a little boring to wear, but other things are fine."
"That seems to be okay. I think of ways to reduce weight and adjust the air permeability." Chen Xin took a pen and wrote down what his father had said in a notebook on the side.
After taking off the slightly heavy exoskeleton protective suit, Chen Xin's father said to his son: "The problem with clothes is all small things. The key is this exoskeleton. You are designed to do things for people. When you wear it, it will not affect the flexibility of the body in the first place.
To design a thing, you must first figure out what you design it for. All your designs and functions should be designed around this core function. If your design deviates from this core function, then your design itself is wrong. Yes, no matter how good the design is, it goes against your original purpose.
So think about it carefully, what is your purpose for designing this thing, what you want to achieve with it, what kind of effect you achieve, and whether your existing design is designed around this core. "
After saying all these words earnestly, Chen Xin's father patted his son on the shoulder, and Chen Xin's mother called for help.
Chen Xin was taught so much by his father, and he also re-adjusted his thinking and put the entire exoskeleton protective clothing neatly on the workbench, intending to readjust it.
The key point that Chen Xin's father mentioned is that there are problems in the joint design of the exoskeleton.
For human bone joints, it is not so easy to put them on a mechanical exoskeleton. The more flexible the mechanical joint, the more complicated the mechanism.
In order to reduce costs, Chen Xin uses swing connections in the connection of exoskeleton joints, which can only swing to a certain extent in one plane. For flexible activities, multiple joints are required to cooperate.
This undoubtedly limits the joint range and flexibility of the exoskeleton.
It's okay to put it on the lower limbs. After all, the two legs of human beings mostly do pendulum movements, and they only need to swing back and forth. No one will be bored and split.
But for the upper limbs, this design is a bit embarrassing.
The upper limbs of the human body, that is, the arm, in addition to the knuckles of the palm, also have four joints: shoulder, elbow, wrist and radioulnar.
The shoulder joint has the functions of flexion, extension, abduction, and internal and external rotation. Therefore, the joint head is spherical and is called a spherical joint. With the advantages of the spherical joint structure, the shoulder joint can bend 0°~180°, and extend 0°~180°. °~50°, abduction 0°~180°, internal and external rotation 0°~90°, it is one of the most flexible joints in the human body, even more flexible than the wrist joint.
Chen Xin's father said that he couldn't raise his arm, which was largely affected by the movable joints of the exoskeleton in the shoulder.
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After all, Chen Xin uses two pendulums to connect the shoulder joints of the exoskeleton. One is responsible for swinging back and forth, and the other is responsible for swinging up and down. The cooperation of the two joints can also allow the arm to move flexibly within a certain range.
It can be limited by the limitation of the structure itself, plus the need to connect the auxiliary structure, the flexibility of this part is limited.
The most obvious manifestation is that the user's arms cannot be raised higher than the shoulders, and there is no way to bend backwards.
In addition, the connecting joint of the exoskeleton elbow can only do 0°~90° flexion and extension due to the problem of the connection structure. Compared with the normal arm joint 0°~150° flexion and extension, the foot is 60° less The range of motion makes it impossible for users to take off the helmet on their heads with their own hands.
If you want to improve flexibility~EbookFREE.me~, you can only adjust the connection structure of the exoskeleton joint, increase its movement angle, or adopt a more complex structure to make it more flexible.
It is not impossible to use spherical joints that have the same structure as human bones. It is just that there is a layer of cartilage on the connecting surface of the bones and joints of the human body.
Even so, there are still people who suffer from severe joint wear and joint strain due to high-intensity work.
For machinery, mechanical wear will be an unavoidable problem if it is replaced with a spherical joint.
If it is impossible to regenerate, only bearings and lubrication can be used to reduce friction, or replacement after serious wear, but frequent replacement will undoubtedly increase maintenance costs, contrary to Chen Xin's original intention to reduce costs.
Moreover, the use of ordinary metal materials on the spherical joints cannot support high-strength use, and the use of wear-resistant high-strength materials will increase the cost.
In addition, only adding more movable joints to achieve a more flexible movement angle, but the complex structure will make maintenance extremely troublesome, which makes Chen Xin suddenly fall into a bald cycle.