Safety-Related Limiting Mechanisms; Singularity/Singular Point - Techman Robot TM5 Series Manual Book

2.3 Safety-related Limiting Mechanisms

All safety-related functions described in Section 2.1 are monitored and controlled by a dedicated safety
thread (with a cycle of 10ms) at system level, which provides a trigger signal to another dedicated motion
thread (with a cycle of 1ms) to make related responses. In this dedicated safety thread, all physical
quantities used for calculation of the required information about each robot axis (angle, angular velocity,
torque, etc.) are also updated every 1ms. When any safety related function is triggered, every axis of the
robot will stop within 800ms under a Category 2 Stop. When the Emergency Stop button is pressed, the
robot will stop movement within 610ms and the system will lower the upper limit of the total drive current
from 20 A to 3 A to activate a Category 1 Stop. In addition, when system hardware is operating beyond
limits (such as too high joint drive current, overheating motor, unstable power supply, or disconnection of
the system communications), a Category 2 Stop is triggered. When a Category 1 Stop or Category 2
Stop is triggered, the Indication Light Ring on the end of the robot will change to a solid red light and the
system will signal a long beep. When this happens, restart the system according to standard procedure,
or contact the distributor for servicing.
Operating on the periphery of the non-working area of the Techman robot or if the range of
motion passes through the non-working area (Jacobian matrix is unstable near singularities)
may also cause the end tool output force to incorrectly trigger safety conditions even at low
Warning
speeds. Please set the task requirements of the robot inside its working space to ensure the
correct operation of the safety protection.

2.4 Singularity/Singular Point

Robot arm do not move through whole space always, it has a number of safety-related issues. Kinematic
singularities play a significant role in the motion control of robot arm. Singularity can be defined as a
position in the robot workspace where two or more joints no longer independently control the position
and orientation of the tool. Namely, for a general 6-axis manipulator, this means that singularity is a point
where the robot loses its ability to move the tool center point in some orientations. The error code are
0x09、0X14.
TM robots with 6 degrees of freedom have three clarifications in singularity:
 Inner singularity
 Extended singularity
 Wrist axis singularity
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