Decoupled four-degree-of-freedom telecentric mechanism for minimally invasive abdominal surgery

Abstract

A decoupling four-degree-of-freedom telecentric mechanism for celiac minimally invasive surgery comprises a rack, an end effector, a first moving branched chain and a second moving branched chain. The rack is provided with a first support and a second support, the first moving branched chain is connected between the first support and a first end of the end effector, and the second moving branched chain is connected between the second support and a second end of the end effector; through active movement of the first moving branched chain, passive movement of the second moving branched chain and autorotation movement of the end effector, three-rotation one-movement four-degree-of-freedom movement of the end effector around a rotating center far away, and three rotation degrees of freedom are controlled through single drivers respectively, so that the telecentric mechanism has decoupling movement characteristics. The telecentric mechanism can realize decoupling four-degree-of-freedom movement around the rotating center far away, and a driving motor is close to a base and away from the end effector, so that lighter mass and smaller movement inertia of the end effector of a celiac minimally invasive surgery robot are realized, and surgical safety is improved.

Description

technical field [0001] The invention relates to a medical robot, in particular to a decoupling four-degree-of-freedom telecentric mechanism for minimally invasive abdominal surgery. Background technique [0002] Parallel mechanisms are widely used in heavy-duty simulation equipment, robots, CNC machine tools, sensors and micro-operation fields. However, the drive units of the parallel mechanism are coupled, that is, the movement of the overall output platform of the parallel mechanism in any direction is the synthesis of the motions of all drive units, and the movement of each drive unit is combined with the overall movement of the parallel mechanism (i.e. input and output ) is non-linear. This characteristic leads to complex control of parallel mechanism, difficult calibration, and restricts the improvement of accuracy. Therefore, how to achieve decoupling of parallel mechanisms to simplify control and calibration and improve motion accuracy has always been a difficult an...

AI Technical Summary

Problems solved by technology

There are many classic cases in the development of telecentric mechanisms. For example, the five-link telecentric mechanism developed by the University of Tokyo is very easy to disassemble and assemble, which is convenient for robot disinfection, but its rigidity is slightly poor.

The spherical telecentric mechanism developed by the University of Washington uses the principle that the axis of the spherical joint passes through the center of the sphere to ensure the fixed-point four-degree-of-freedom movement of the end surgical instrument. This mechanism is very compact and easy to achieve miniaturization, but the drive problem of this mechanism Complex and difficult to control due to complex kinematics

There is also a compound parallel four-bar telecentric mechanism applied by da Vinci, which is very good in terms of stiffness and movement space, but it requires high machining accuracy, and at the same time, the weight of the end effector is large and the inertia is large.

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