Static stability is all about the initial tendency of a body to return to its equilibrium state after being disturbed To have a statically stable equilibrium point, the vehicle must develop a restoring force/ moment to bring it back to the eq. condition Later on we will also deal with dynamic stability, which is concerned with the time history of the motion after the disturbance

Note can develop good approximation of key aircraft motion(Phugoid) using simple balance between kinetic and potential energies. Consider an aircraft in steady, level flight with speed U and height ho. The motion is perturbed slightly so that

Matrix Diagonalization Suppose a is diagonizable with independent eigenvectors use similarity transformations to diagonalize dynamics matrix

Recall from 6-2 that the derivative stability derivative terms zai, and Mi ended up on the lhs as modifications to the normal mass and Inertia terms displaced air is \entrained\and moves with the aircraf rounding These are the apparent mass effects- some of the sur Acceleration derivatives quantify this effect Significant for blimps, less so for aircraft e Main effect: rate of change of the normal velocity w causes a transient

Aircraft Lateral dynamics Using a procedure similar to the longitudinal case, we can develop the equations of motion for the lateral dynamics

Altitude Controller In linearized form, we know from 1-5 that the change of altitude h can be written as the flight path angle times the velocity, so that

Analysis to date has assumed that the atmosphere is calm and fixed -Rarely true since we must contend with gusts and winds -Need to understand how these air motions impact our modeling of the aircraft. Must modify aircraft equations of motion since the aerodynamic forces and moments are functions of the relative motion between the aircraft and the atmosphere, and not of the inertial velocities

USuALLY WE NOT KNOw THE \ACTUAL SYSTE\ So How WE ESTABLISH IF OUR MODEL Is Goo0? VARIOUS TPES OF TESTS CAN BE PERFORMEO PREDICTION ANO SIMULATIONJ ERRORS FRERUENCY RESPONSE FIT >MAKE SVRE YOU USE O1FFERENT 4TA To

本章介绍学习关于 Prolog编程最基本的内容,包括Horn子句 Prolog、推理 机、程序控制、 Prolog算符等。 Visual Prolog是面向对象的、严格类型化的和模式检验的。在编写 Visual Prolog程序时,必须掌握这些内容。但在这里,我们将集中于编写代码这个 核心问题,也就是说,编写这些代码时暂时不考虑类、类型和模式。 我们将使用包含在 Visual Prolog6中的PIE例子。PIE是一个 Prolog经典的 解释器,通过使用它,可以学会和试验 Prolog程序,而不必关心类、类型等 方面的知识

一、信息系统的规划 二、信息系统的实现方法 三、信息系统的管理和控制 四、地理信息系统(农业资源信息系统)的设计与评价