Robot system with object detecting sensors

A robot system comprising:

• a base;
• a plurality of movable linkages driven by joints with actuators, wherein a movable linkage in the plurality of movable linkages farthest from the base has a tool end and is configured to drive the tool end along and/or about an axis, the joints comprise a pivot joint hinging a proximal linkage and a distal linkage from the plurality of movable linkages, the pivot joint has at least one pivot axis, and the pivot joint is located in an elbow or a wrist of the robot system;
• at least one joint monitoring sensor configured to monitor the joints;
• a plurality of object detecting sensors mounted to at least two movable linkages of the plurality of movable linkages, wherein each object detecting sensor has a field of view, and wherein at least one group of object detecting sensors are mounted around the pivot joint and comprise:
• a first object detecting sensor configured to have a field of view oriented to cover a radial direction of the pivot joint, and
• a second object detecting sensor configured to have a field of view oriented to cover an axial direction of the pivot joint;
• and
• one or more processors communicably coupled to the joint monitoring sensors and the plurality of object detecting sensors, the one or more processors being configured to:
• detect an external object based on information generated by the plurality of object detecting sensors, and
• when the external object is detected intruding on a first monitoring zone, reduce a moving speed of at least one movable linkage of the plurality of movable linkages.