TY - JOUR
T1 - Learning control strategies for high-rate materials testing machines
AU - Schlotter, Michael
AU - Plummer, Andrew R
PY - 2011/12
Y1 - 2011/12
N2 - Hydraulic high strain rate materials testing machines are required to track a user-defined velocity profile during tensile or compression tests in the face of sudden large impact forces. Due to delays and limited bandwidth of the actuation system, causal feedback/feedforward controllers fail to compensate for these disturbances. This paper presents more suitable non-causal learning control strategies, which anticipate the impact and take corrective action in advance. Two control strategies are discussed. The first comprises an iterative algorithm, which calculates a command signal correction by passing the velocity error observed in the previous test through an inverse model linearized around the target velocity. In the second approach, a detailed nonlinear inverse model is used to obtain a command signal from demand motion and force data. It is concluded that the first method is superior if two or more iterations can be performed.
AB - Hydraulic high strain rate materials testing machines are required to track a user-defined velocity profile during tensile or compression tests in the face of sudden large impact forces. Due to delays and limited bandwidth of the actuation system, causal feedback/feedforward controllers fail to compensate for these disturbances. This paper presents more suitable non-causal learning control strategies, which anticipate the impact and take corrective action in advance. Two control strategies are discussed. The first comprises an iterative algorithm, which calculates a command signal correction by passing the velocity error observed in the previous test through an inverse model linearized around the target velocity. In the second approach, a detailed nonlinear inverse model is used to obtain a command signal from demand motion and force data. It is concluded that the first method is superior if two or more iterations can be performed.
UR - http://www.scopus.com/inward/record.url?scp=84856392827&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1177/0959651811404871
U2 - 10.1177/0959651811404871
DO - 10.1177/0959651811404871
M3 - Article
SN - 0959-6518
VL - 225
SP - 1125
EP - 1135
JO - Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering
JF - Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering
IS - 8
ER -