Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Feb 1;12(1):98-106.
doi: 10.1109/TMECH.2006.886258.

A New Type of Motor: Pneumatic Step Motor

Affiliations

A New Type of Motor: Pneumatic Step Motor

Dan Stoianovici et al. IEEE ASME Trans Mechatron. .

Abstract

This paper presents a new type of pneumatic motor, a pneumatic step motor (PneuStep). Directional rotary motion of discrete displacement is achieved by sequentially pressurizing the three ports of the motor. Pulsed pressure waves are generated by a remote pneumatic distributor. The motor assembly includes a motor, gearhead, and incremental position encoder in a compact, central bore construction. A special electronic driver is used to control the new motor with electric stepper indexers and standard motion control cards. The motor accepts open-loop step operation as well as closed-loop control with position feedback from the enclosed sensor. A special control feature is implemented to adapt classic control algorithms to the new motor, and is experimentally validated. The speed performance of the motor degrades with the length of the pneumatic hoses between the distributor and motor. Experimental results are presented to reveal this behavior and set the expectation level. Nevertheless, the stepper achieves easily controllable precise motion unlike other pneumatic motors. The motor was designed to be compatible with magnetic resonance medical imaging equipment, for actuating an image-guided intervention robot, for medical applications. For this reason, the motors were entirely made of nonmagnetic and dielectric materials such as plastics, ceramics, and rubbers. Encoding was performed with fiber optics, so that the motors are electricity free, exclusively using pressure and light. PneuStep is readily applicable to other pneumatic or hydraulic precision-motion applications.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Kinematic diagram of the PneuStep motor.
Fig. 2
Fig. 2
Transmission ratio and step size.
Fig. 3
Fig. 3
Isometric view and two central cross sections of the motor.
Fig. 4
Fig. 4
Two sizes of motor prototypes.
Fig. 5
Fig. 5
Rotary distributor.
Fig. 6
Fig. 6
Optical sensor using hoop gear (left) or 3-mark code-wheel (right).
Fig. 7
Fig. 7
PneuStep driver.
Fig. 8
Fig. 8
Torque versus speed with 3-m hose and rotary pump.
Fig. 9
Fig. 9
Motor stall speed versus (a) hose length with rotary pump (b) supply pressure with electronic pump and 7-m hose.
Fig. 10
Fig. 10
Open-loop, PID, and modified PID tests.
Fig. 11
Fig. 11
MRI-compatible robot with six PneuStep motors.

Similar articles

Cited by

References

    1. Choi HS, Han CS, Lee KY, Lee SH. Development of hybrid robot for construction works with pneumatic actuator. Autom Construc. 2005;14:452–459.
    1. Hagglund T. A friction compensator for pneumatic control valves. J Process Control. 2002;12:897–904.
    1. Bendov D, Salcudean SE. A force-controlled pneumatic actuator. IEEE Trans Robot Autom. 1995 Dec;11(6):906–911.
    1. Butefisch S, Seidemann V, Buttgenbach S. Novel micro-pneumatic actuator for MEMS. Sens Actuators A, Phys. 2002;97–98:638–645.
    1. vanVarseveld RB, Bone GM. Accurate position control of a pneumatic actuator using on/off solenoid valves. IEEE/ASME Trans Mechatronics. 1997 Sep;2(3):195–204.

LinkOut - more resources