HS code-focused compliance audits

List of contents of this article:

• 1,HS code-focused compliance audits Judgement on stability in the signal and system
• 2, What is a continuous transportation system
• 3, What is the definition of continuous control system?
• 4, continuous time system
• 5, the difference between powergui continuous and discrete
6, What are the sufficient necessary conditions for the stability of the continuous control system?

In the signal and system, the judgment of stability

1, the system is subjected to some interference and deviates from the normal state. When the interference is eliminated, its normal state can be restored, then the system is stable; on the contrary, once the system deviates from its normal state, it cannot be restored to the normal state. If the state is normal and the deviation is getting bigger and bigger, the system is unstable.

2. If the output of a linear system finally returns to its equilibrium state under the action of the initial conditions, then this system is stable. 2 If the output of a linear system presents a continuous isoamplitude oscillation process, it is called critical stability.

3. The stability judgment of a continuous system proposed by Ross-Holwitz, the four properties of the system are linearity and time invariance.Causality and stability are very important. The main methods to judge the stability of the system are: Nyquist stability judgment and root trajectory method.

4. In the signal and system, if the discrete system is stable, the poles of the system function must all be located within the unit circle. When the output y (t1) of t=t1 only depends on the input x (t≤t1) of t≤t1, then this system is a causal system.

What is a continuous transportation system

Continuity means that the operation of transportation from departure to destination is not easily interrupted by other conditions. For example, pipeline transportation, as long as it is completed, the transportation can be operated all the time without considering whether the weather is bad or not.

Continuity is manifested as the continuity of the transportation production process and the continuity of transportation production time.The continuity of the waterway is the worst, firstly, because the goods (passengers) generally need to transfer from the starting point to the end, and secondly, the transportation time is often easily interrupted by natural conditions. It is greatly affected by natural conditions.

Belt conveyor, as a common conveying equipment, is widely used in various industrial fields. The belt conveyor has the ability of continuous conveying. Through a seamless belt, it can continuously and smoothly transport various materials, so as to achieve the efficient operation of the production process. The belt conveyor has high adaptability.

What is the definition of continuous control system?

1. This system is a control system that can monitor and adjust continuous variables in real time. The difference between the two is system performance and response speed.System performance: The continuous control system is measured and controlled in a continuous process of time, so it has better dynamic performance and steady-state performance.

2. For example, the steering wheel of a car is an example of continuous control. The driver continuously turns the steering wheel appropriately to control the direction, which is similar to the control system of the steering wheel of a car, which is the continuous inspection control system.

3. The control system can be divided into continuous control system and discrete control system. In the control system studied in the previous chapters, each variable is a continuous function of time, which is called a continuous control system.

Continuous time system

The first-order continuous time system refers to a linear passive system described by a first-order differential equation, and there is a continuous, linear time-invariant relationship between input and output.

The continuous time system studies the characteristics of the system according to the input and output relationship of the system. General system General system refers to a physical system composed of transmission channels or electronic components. For example, a seismic pulse propagates in the underground stratum, returns to the ground after reflection or refraction, and is received by a seismic detector, which can be called a stratum system.

Dynamic systems can be divided into two categories according to continuous time systems: time-varying system and time-invariant system. Among them, the time-invariant system, also known as the steady system, refers to a system in which its characteristics do not change with time.

It can be proved that for a continuous-time linear system, causality is equivalent to arbitrary t0 and arbitrary input x(t). If x(t) is zero at tt0, the corresponding output y(t) must also be zero at tt0.That is, the assumption of "initial relaxation" or "initiation static".

Given a complete modeling vector space E (for example), set U be an open subset of E. Consider an autonomous nonlinear dynamic system: the state vector of the system is a continuous function on the U.

The difference between continuous and discrete

1. The continuity mentioned below refers to the continuity in time, and the continuous model refers to the continuous time model. Discrete refers to time discrete, discrete model refers to discrete time model, and in the physical world, they all belong to continuous systems.

2. Continuous system: The change of system state is continuous in time. Discrete system: Changes in system state only occur at a certain point in time.

3. You are right. The so-called continuous is actually also the selection of some numerical algorithms. The most commonly used ones are Eula's method, the fourth and fifth-order dragon Gekuta method, etc., which approximates the continuous solution and personal insights for many years.

4. Simulink can set up continuous simulation in powergui to turn continuous signals into discrete signals.

5. Power refers to the analysis of power systems, and can also be used for power electronics, motors, etc. Powergui can be configured by double-clicking. There are options such as continuous and discrete in solver, which indicates what method is used in matlab to solve equations. The smaller the step length setting at discrete, the higher the accuracy, and the slower the simulation.

What are the sufficient necessary conditions for the stability of the continuous control system?

1. The necessary condition for system stability is that the essential condition for system stability The essential condition for system stability is that all the elements in the first column of the table are greater than zero and cannot be equal to zero. Next, let's learn about the following necessary conditions for system stability.

2. The sufficient necessary condition for the stability of the continuous control system is that the closed-loop poles are located on the left side of the S plane; the sufficient necessary condition for the stability of the discrete control system The roots of the characteristic equations of the system are in the unit circle with the origin as the center on the Z plane.

3. In classical control theory, the sufficient necessary condition for system stability is that when time tends to infinity, the unit pulse of the system is correspondingly equal to zero.To determine whether a system is a stable system, many judgments can be used, such as Hervetz judgment, Laws judgment, etc.

4. The conditions are as follows: the sufficient condition for the stability of a system is that the real parts of all feature roots of the system are all less than zero, or all the poles of the system transfer function are distributed in the left half-plane of the s plane.

5. First, write Δ according to the characteristic equation. The sufficient necessary conditions for system stability: the main determinant Δn and the sub-determinants Δ1, Δ2, Δ3, Δ, Δn-1 on its diagonal have positive values.