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Human-Inspired Hyper Dynamic Manipulation
motion trajectory that can utilize it effectively during the whole motion
phase. However, the complicated relation between the effect of dynamically
coupled driving and the motion states and the strict active torque limitation make it difficult to find such a motion trajectory directly. We deal with
this problem by adopting an optimization method. The trajectory of hyper
dynamic manipulation is generated subject to the active torque limitation
and motion equation. If the motion can be generated under this condition,
then dynamically coupled driving is to be utilized to drive the manipulator
in the motion rather than the active torque.
4.2.2 Utilization of Structural Joint Stop
The other key point for human hyper dynamic manipulation is the structural
joint stop utilized by humans. Much work has already been done investigating the elastic and damping characteristics of the joint stop. Some work (Hogan
1985) has focused on realizing the desired compliance by controlling the joint
actuators, whereas others (Hayakawa et al. 1996; Katsurashima et al. 1998;
Laurin-Kovitz, Colgate, and Carnes 1991; Mizuuchi et al. 1998; Morita et al. 1998;
Okada, Nakamura, and Ban 2001) tried to utilize special mechanisms in order
to meet the compliance requirements. All of the work previously mentioned is
based on an assumption that the load is within the load capability of all actuators in the joints.
Our proposal is different. We propose the passive elastic and damping
characteristics of the structural joint stop within the stop positions of the
joint to be utilized to improve the capability of dynamic manipulation of
manipulators, in addition to the elastic and damping characteristics realized
by controlling the actuators or supplied by some mechanisms within the
rotation range of a joint.
The reasons for using the structural joint stop in a manipulator are as
follows:
• Large load capability: The load capability of a mechanical joint stop
depends on its structural strength, instead of the load capability
of an actuator. This will be useful to transfer high power from the
joints near the base to the joints near the end of the manipulator.
• Easy realization by simple and compact mechanism: The structure of the
joint stop can be built into the joint as a simple module, instead of a
conventional stiff joint stop.
• Power savings: The configuration of a manipulator, in which some or
all joints are in joint stop positions, can be used as a rest configuration. By switching off the servo loops of the joints in joint stop positions, power savings is possible.
Human-Inspired Hyper Dynamic Manipulation
motion trajectory that can utilize it effectively during the whole motion
phase. However, the complicated relation between the effect of dynamically
coupled driving and the motion states and the strict active torque limitation make it difficult to find such a motion trajectory directly. We deal with
this problem by adopting an optimization method. The trajectory of hyper
dynamic manipulation is generated subject to the active torque limitation
and motion equation. If the motion can be generated under this condition,
then dynamically coupled driving is to be utilized to drive the manipulator
in the motion rather than the active torque.
4.2.2 Utilization of Structural Joint Stop
The other key point for human hyper dynamic manipulation is the structural
joint stop utilized by humans. Much work has already been done investigating the elastic and damping characteristics of the joint stop. Some work (Hogan
1985) has focused on realizing the desired compliance by controlling the joint
actuators, whereas others (Hayakawa et al. 1996; Katsurashima et al. 1998;
Laurin-Kovitz, Colgate, and Carnes 1991; Mizuuchi et al. 1998; Morita et al. 1998;
Okada, Nakamura, and Ban 2001) tried to utilize special mechanisms in order
to meet the compliance requirements. All of the work previously mentioned is
based on an assumption that the load is within the load capability of all actuators in the joints.
Our proposal is different. We propose the passive elastic and damping
characteristics of the structural joint stop within the stop positions of the
joint to be utilized to improve the capability of dynamic manipulation of
manipulators, in addition to the elastic and damping characteristics realized
by controlling the actuators or supplied by some mechanisms within the
rotation range of a joint.
The reasons for using the structural joint stop in a manipulator are as
follows:
• Large load capability: The load capability of a mechanical joint stop
depends on its structural strength, instead of the load capability
of an actuator. This will be useful to transfer high power from the
joints near the base to the joints near the end of the manipulator.
• Easy realization by simple and compact mechanism: The structure of the
joint stop can be built into the joint as a simple module, instead of a
conventional stiff joint stop.
• Power savings: The configuration of a manipulator, in which some or
all joints are in joint stop positions, can be used as a rest configuration. By switching off the servo loops of the joints in joint stop positions, power savings is possible.