Table 1 Nomenclature.

From: Real-time robust generalized dynamic inversion based optimization control for coupled twin rotor MIMO system

Expression

Description

Expression

Description

\(\theta\)

Pitch (elevation) angle

\(\phi\)

Yaw (azimuth) angle

\(\tau _1\)

Momentum of main rotor

\(\tau _2\)

Momentum of tail rotor

\(I_1\)

Main rotor inertia

\(I_2\)

Tail rotor inertia

\(x \in R\)

(real number) of states

\(u \in R\)

input signal

\(\rho\)

Euclidean error norm

D

Diagonal matrix

Y

Control vector

P

Projection matrix

\(a_1\)

Constant

\(b_1\)

Constant

\(a_2\)

Constant

\(b_2\)

Constant

\(M_g\)

Gravitational momentum

\({B_{1\theta }}\)

Frictional parameter

\({B_{2\theta }}\)

Frictional parameter

\({B_{1\varphi }}\)

Frictional parameter

\({B_{2\varphi }}\)

Frictional parameter

\(k_{gy}\)

Gyroscopic parameter

\(k_1\)

Gain of main motor

\(k_2\)

Gain of tail motor

\(T_{11}\)

Denominator constant of main motor

\(T_{10}\)

Denominator constant of tail motor

\(T_{21}\)

Denominator constant of main motor

\(T_{20}\)

Denominator constant of tail motor

\(u_{h}\)

Horizontal axis control input

\(u_{v}\)

Vertical axis control input

\(I_v\)

Inertial momentum of main rotor

\(I_h\)

Inertial momentum of tail rotor

\(e_z (t)\)

Tracking of pitch and yaw angles

2DOF

Two degree of freedom

\(k_{H_h }, k_{H_v}\)

Velocity gains

\(k_{f_h }, k_{f_v }\)

Frictional momentum

\(R_V\)

Returned torque of rotors

\(G_d\)

Disturbance of plant

\(G_u\)

Transfer matrix of control signal

\(K_y\)

Feedback matrix functions

\(K_r\)

Transfer function matrix of pre-filter

r, d

Reference input, input disturbance

\(\Delta _F\)

Fictitious perturbation

\(S_o\)

Output sensitivity matrix