Effect of Pantograph’s Main Structure on the Contact Quality in High-Speed Railway

Table 1

The physical meaning of the symbols in Figure 4.

Symbols	Physical meaning
O1, x1, y1	Global coordinate system
O1, O2, O3, O4, O5	Hinge points
	Local coordinate fixed on link
	Local coordinate fixed on upper frame
	Local coordinate fixed on supporting rack
	Local coordinate fixed on lower frame
L1, L2, L3, L4	Length
C1, C2, C3, C4	Center of mass
m1, m2, m3, m4	Mass
J1, J2, J3, J4	Moment of inertia around the center of mass
θ10, θ20, θ30, θ40,	Initial angle
θ1, θ2, θ3, θ4	Relative motion angle
L5	The length between O2 and O5
T	Raise torque
QL, QR	Left and right forces action on supporting rack
	Gravity acceleration