
372 Virtual Reality: Concepts and Technologies
Impedance
Mode
Admittance
Mode
Control
X
target
X
proxy
F
haptic
F
simul
Haptic
Device
Simulation
g
s
p k
s
g
d
p k
d
Figure 16.4 Admittance to impedance adaptation
because in the case of a virtual wall, the position calculated by the simulation can
accurately maintain the contact and avoid interpenetrations. The behaviour of the vir-
tual object is determined by the environment and its position is not controlled directly,
but indirectly by the forces measured by the device. The functioning of the avatar is
thus completely similar to the other objects of the simulation and simply receives an
additional force. Since