Affiliations: [a] School of Automation Science and Electrical Engineering, Beihang
University, Beijing, China | [b] Department of Mechatronics, Singapore Institute of
Manufacturing Technology, Singapore, Singapore
Correspondence:
[*]
Corresponding author: Chen Weihai, School of Automation Science and Electrical
Engineering, Beihang University, Beijing 100191, China. Tel.: +86 8231 5920;
Fax: +86 8231 5920; E-mail: whchen@buaa.edu.cn
Abstract: This paper presents the concept design of a novel uniaxial force
sensor with two stage force resolutions. Unlike conventional stain-gauge-based
force sensing devices, the developed force sensor measures an external force
through measuring the displacement of a movable member suspended by a compliant
mechanism. The compliant mechanism is specially designed to have two stiffness
values within its workspace. The low stiffness is used for small range and fine
resolution force measurement, while the high stiffness is used for large range
and coarse resolution force measurement. In order to get the required
performance, the static stiffness as well as the dynamics of the sensing system
is analyzed both analytically and numerically. After a prototype sensor is
fabricated, preliminary characterization tests are carried out to verify the
accuracy of the theoretical model and validate the effectiveness of the
proposed design. The experimental results indicate that the structure of the
force sensor is compact, and it has the ability to measure both micro range and
macro range forces within one setup, meanwhile keeps very fine resolutions.
Keywords: Force sensor, compliant mechanism, static stiffness, natural frequency
