JOURNAL OF COMPUTERS (JCP)
ISSN : 1796-203X
Volume : 3    Issue : 8    Date : August 2008

Task-based Dynamic Fault Tolerance for Humanoid Robot Applications and Its Hardware Implementation
Masayuki Murakami
Page(s): 40-48
Full Text:
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Abstract
This paper presents a new fault tolerance scheme suitable for humanoid robot applications. In the future,
various tasks ranging from daily chores to safety-related tasks will be carried out by individual humanoid
robots. If the importance of the tasks is different, the required dependability will vary accordingly. Therefore,
for mobile humanoid robots operating under power constraints, fault tolerance that dynamically changes
based on the importance of the tasks is desirable because fault-tolerant designs involving hardware
redundancy are power intensive. In the proposed fault tolerance scheme, a duplex computer system
switches between hot standby and cold standby according to each individual task. However, in mobile
humanoid robots, a safety issue arises when cold standby is used for the standby computer unit. Since an
unpowered unit cannot immediately start to operate, a biped-walking robot falls down when failover occurs
during cold standby. This paper proposes a safety failover method to resolve this issue and describes the
hardware design of the safety failover subsystem.

Index Terms
task-based dynamic fault tolerance, duplex computer system, safety, humanoid robot