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Matching the direction of the vector sum of the left and right front wheels with those of the rear wheels is called thrust adjustment.
In wheel alignment it is commonly known as camber, castor and toe, but the steering structure is more complicated for turning action.
Steering construction has a lot of three-dimensional ingenuity to make it easy to turn on the front wheels that control steering and to ensure straightness.
An angle is provided on the rotation axis of the hub during steering, and this is called the kingpin angle. In the case of the strut mechanism, it is called the strut axis inclination, SAI. This is the first adjustment standard for the front toe-in amount, which greatly affects the steering feeling when turning.
Here, a concept that has been misunderstood for a long time has been said that "front toe-in is given to ensure straightness", but this is a big mistake.
As a matter of fact, as you can see by actually trying it, it has better straight-line stability in toe-out than in toe-in under negative camber conditions of about 20 minutes at the front.
Again, we set the front toe-in adjustment criteria to zero and we observes the 20 degree rotation angle difference and make fine adjustments if necessary.
"Not to ensure straightness", "But to establish 20 degree rotation angle difference."
When going straight, it is the centrality of the Rear wheels, that is, the thrust, which determines the driving direction of the car, Not the front wheels.
When the direction of the vector sum of the left and right front wheels and the direction of the vector sum of the left and right rear wheels match, "When the Thrust Angle is Zero", the geometric Axsle construction keeps the car going straight without operating the steering wheel.

I've talked about the negative effects of thrust angles in passenger cars and the need to eliminate them, but today he talks about the possibilities.
If you operate the steering even a little while going straight, the car will change the direction of driving. The driver should know the direction change very sensitively. Then, is it the same with a forklift with rear wheel steering? The same thing will happen physically.
Let's assume a state where both front wheel steering and rear wheel steering functions are provided. When the rear wheels are fixed at the center position that matches the traveling direction, the front wheels can also be kept straight at the steering center position.
If you steer the rear wheel slightly to either side and shift it from the center, the car will start turning, and if he tries to keep going straight in this state, the front wheel must be in phase and steered at the same angle as the rear wheel.
The direction of the left-right vector sum of the rear wheels and the deviation angle from the center of the car may be called as the thrust angle, or the vector sum corrected by the front wheels.
If you write so far, it is easy to think that you should correct the deviation angle on the rear wheel, but in reality it is not easy because there are many uncertainties.
When the arc drawn by the thrust angle and the radius of the curve match when turning, a dead zone occurs in the steering pressure. At this time, the car turns along the curve even if you take your hand off the steering wheel.
Since the load moves back and forth when starting and stopping, he changes the amount of correction for thrust.
When the forward weighted movement is stopped, it will be over if it starts at the steering position as it is, and it will be undercut and it will be necessary to increase the number of turns. The steering action is complicated due to the action, and it feels uncomfortable. Even if the car is equipped with EPS, the basic geometric and physical deviation cannot be corrected.
It is an unreasonable consultation as if he is trying to correct the roll movement habit that should be corrected by the aileron tab on the airplane from the yaw movement by force on the rudder tab. Unpredictable bad habit appears when the driving situation changes.

Yesterday, I mentioned about the thrust angle of automobiles and its influence, and the necessity of installing a thrust angle adjustment trim mechanism.
Today I want to tell the practice and results of error adjustment in the absence of a trim mechanism about almost every car.

It must be possible to adjust the thrust angle to zero while driving, depending on the keen human senses relatively easily.
As an usual manner, if this is not possible, we must establish it by repeating cut and error, considering all the uncertainties unrealistically.
This thrust adjusting procedure requires a relentless determination and tenacity to accomplish it at any rate, mentally and physically, while repeating extremely troublesome adjustments, efforts to bring the infinitely misaligned thrust angle closer to zero continue endlessly.

"But when the ideal zero-thrust condition is achieved, he will immediately be impressed by the joyous and wonderful handling that the driver has never experienced before.
Once he tastes this feeling, he doesn't want to drive a car that has a misaligned thrust."
In other words, when he establishes zero thrust for a car that he wants to let go, he always changes his mind and decides. It's supposed to change, because he's got rid of everything that had the potential to feel uncomfortable.

A car that flows to the right, a car that does to the left, a car that has to change direction immediately when it receives some external disturbance, and a car that has to be corrected in a hurry.
However, from a geometrical point of view, there is no peculiar habit regarding the direction during exercise. It can be changed in any way depending on the adequate adjustment.
The steering sensation of the vehicle which is easily disturbed by some external stimulation, is fixed and stable at an adequate position around the center with comfortability under appropriate resistance.

Recently, I felt uncomfortable with the steering of the Audi A-3 DBA-8PCAX, so I measured the thrust angle with a laser pointer device. As a result, the angle value was a plus of 0.6 minutes. Because it is a sufficiently acceptable value of 3 digits or less, if the thrust angle is 10 minutes that is torrelance of European Automobile Safety Standard, if you go straight for 100 m, you will draw an arc to either the left or right for about 3 m. This deviation is unknowingly corrected by the driver. Then, if you continue to drive the car while correcting such a deviation, how about 0.6 minutes? Since the deviation is positive under the same conditions, it will occur 23 cm to the left and you will go straight while correcting this. As the thrust angle increases, the amount of correction increases. The driver has to concentrate on checking and correcting the state of deviation, which is very tiring. The amount of correction of the rudder when receiving a external disturbance varies, so it is unpredictable and driving, I feel sick in such a driving condition.

The recent car is equipped with EPS, and by memorizing the steering position when going straight, it is possible to take the thrust angle to zero in a Pseudo manner, but since it is always running while correcting the thrust, it is not possible to predict disturbance. The countersteering cannot be solved, and the difference between the left and right steering sensations remains the same, so the contribution of the EPS-Cal is only Pseudo.

From the idea of trimming adjustment for neutral position, vehicles need a geometric and physical establishment of axle and wheel alignment.
In the case of an aircraft, the position of the center of gravity changes depending on the condition of the load and burdened fuel, so the pilot always makes trim adjustments to maintain level flight, no matter how it is Autopilot or Human one.
From this point of view, I think that it is necessary to adjust the thrust trim in the direction of travel for automobiles as well, but although some concepts of 4WS have been mentioned, there is no report that delves into this point.

In the case of automobiles, four wheels, it is unlikely that everything is exactly aligned with the all-wheel steering, but the front vector direction is always present independently, and therefore the rear is always present alone. Therefore, match these vector directions, that is, make the thrust zero discrepancy respectively. Should be possible as a matter of fact.
It should be aware of any driver as he gets a bit sticky and stable steering position near the center when the zero thrust discrepancy is established. Almost no one has never experienced this feeling that is difficult to verbalize.

If you want safety and comfort in a vehicle, it's the first to introduce a "Thrust trim mechanism", not an electric motor.
This fact and truth should be known to every car maker.
I'm about to mention on the ultimate difficulty to establish the condition of "Zero Thrust Discrepancy" for ordinary vehicle.

In Japan, which is in control of all military, economic and politics, and continues to be ruled by the specific foreign countries, no matter how much the truth is stated and the right direction are shown, nothing will change. It is the same regardless of whether the ruling party or the opposition party might change.
Even if you are connected on the website, information those are inconvenient for the Japanese Government will be erased immediately, so the public opinion will not change.
Some lawmakers argue in tune with those who say the truth, but he just seems to be trying to sell and stand out.
The person's physiognomy does not show "the Pain of Birth in pursuit of the Truth".
He is merely making a play-stained angry expression in the eyes of the Ukrainian representative who has no enthusiasm to really appeal the truth.
This comedian is on the wrong stage.