It seems that rosservice does not support negative arguments:

rosservice call /robotis/servo_right_tilt_moveangle -0.35 0.1 0
Usage: rosservice call /service [args...]

rosservice: error: no such option: -0

Is there a work-around?

-- 

~Travis Deyle
PhD student @ Georgia Tech's Healthcare Robotics Lab
Co-Founder www.Hizook.com -- Robotics News for Academics & Professionals