Modeling, Validation, and Control of Electronically Actuated Pitman Arm Steering for Armored Vehicle

Table 1

Parameter of the Pitman arm steering model.

Description	Symbol	Value
Moment of inertia of steering wheel		0.035 kg m^2
Viscous damping of steering wheel		0.36 Nm/(rad/sec)
Steering column rotational stiffness		42000 Nm/rad
Angular displacement due to universal joint		20°
Steering arm length		0.2 m
Return pressure		0 N/m^2
Pump flow rate		0.0002 m^3/s
Piston area		0.005 m^2
Cylinder length	L	0.15 m
Orifice flow coefficient		0.6
Fluid density		825 kg/m^3
Fluid volume		m^3
Fluid bulk modulus		N/m^2
Torsion bar rotational stiffness		35000 Nm/rad
Sector gear ratio		0.5
Moment of inertia of steering column		0.055 kg m^2
Viscous damping of steering column		0.26 Nm/(rad/sec)
Coulomb friction breakout force on steering linkage		0.5 N
Gear ratio efficiency of forward transmission		0.985
Gear ratio efficiency of backward transmission		0.985
Steering rotational stiffness due to linkage and bushing		15500 Nm/rad
Metering orifice	and	2.5 mm^2