The Mark 5 system is a 17-Degree of Freedom (DOF) wheel-based robot and is currently under development here at CrossWing Inc. The wheel assembly has been changed to a tri-omni-wheel system, eliminating the need for caster support wheels. The omni-wheel system can also be found in the Nav 2 robot. Directly above the wheel assembly, is the battery compartment, which houses only 1 golf kart battery (rather than 2, like the Mark 4). One battery is sufficient for the robot to perform its tasks under a single charge, and also reduces the overall weight. The spooling assembly has been replaced by a motor module, which uses worm gear reduction rather than the pulley-reduction system in the Mark 4. The motor module is placed above the battery compartment. The motor module provides a tensile force on a system of steel cable which in turn operates each respective degree of freedom. A significant modification from the Mark 4, the Mark 5 implements angular position feedback that is performed at each joint. The new location of the feedback sensors allows cable flex to be compensated by our control system. A newly revised arm is amalgamated into the Mark 5 design. Lower profile, and made of ABS plastics, the new design will allow for more complex part features through rapid prototyping procedures. Videos Mark 5 clearing the table, loading the dishwasher Clearing the table and loading the dishwasher. Mark 5 putting away Putting away the dishes Images

The Mark 4 system is the first floor-based humanoid prototype robot. The 15-DOF robot consists of 2 arms, a head with vision capabilities, an upper body which can rotate about a waist joint, a lower body which houses the spooling system necessary for manipulating all the joints limbs of the robot, and a wheel assembly to allow the robot to move around. The spooling assembly is housed below the waist of the robot, which is also where all the DC motors responsible for the limb motions are located. The spooling assembly performs a series of reductions via pulleys placed over 2 layers, yielding the required ratios to actuate the arms. Cables are connected directly from the DC motors to the reduction system, all the way to the various DOF of the arms. Sensors are mounted on the various motors that are used to manipulate the orientation of the arms. Below the spooling system, we have the battery housing. The Mark 4 prototype runs on 2 golf kart batteries, providing prolonged work life during a single charge. Due to the bulky nature of the batteries, they are placed as close to the floor as possible (just above the wheel assembly), in order to provide counter-balancing weight for the upper-body of the robot. The arms are fabricated mostly out of ABS, except for the shoulder blocks that house the ball bearings necessary for the arm rotation, which are fabricated out of aluminum. The wrist is manipulated ...

The Mark 3 is a concept robot that builds on the Mark 1 and Mark 2 systems. It's unique feature is that it can fold-up and easily store itself in an overhead compartment, unlike the Mark 1 and Mark 2. A two-manipulator system, the Mark 3 concept travels on ceiling based rails to perform its tasks. Although it is ideal for including in new construction or remodeled kitchen projects, it does have a high barrier to entry, and the Mark 4 development began in parallel as a floor based personal robot. Mark 3 Images

The Mark 2 robot is a 5-DOF ceiling-mounted system, similar to the Mark 1. The Mark 2 uses a lighter weight frame than the Mark 1. The wrist on the Mark 2 functions differently than the arms in the rest of the Mark series. The joint which causes the rotation of the wrist is nearer to the gripper than the joint causing wrist flex. As a result, the full Mark 2 arm is limited to move within one plane, with the exception of the turret or shoulder which rotates the entire plane. Additionally, this robot has sensors for each DOF, which assists with the control of each DOF. The turret position is monitored via a 7-bit optical encoder system that is driven by the main turret shaft of the robot via a 1:1 belt-driven connection. The shoulder and elbow joints house rotary potentiometers for initialization then use 2-bit quadrature encoders for relative position updates, whereas the 2 DOF on the wrist-system are monitored via 2-bit quadrature encoders mounted directly onto the motor shafts, which must be zeroed via the limit switches at the edge of the range of motion. Finally the gripper has a linear potentiometer for measuring the amount that the gripper is closed. The joint sensors allow the robot to know its exact position upon start-up and throughout its range of motion. Using all of the sensors plus the dual camera vision system, this arm is able to localize and grasp ...

The Mark 1 robot is the first prototype to be developed at CrossWing Inc. It was a ceiling-mounted arm with 3 degrees-of-freedom (DOF), consisting of a turret, shoulder joint, and arm joint. A wrist-system, adding 2 extra degrees-of-freedom, is attached to the end of the arm. The wrist provides a twisting motion, followed by a flexing motion, as well as a one degree of freedom gripper system based on the Aaron Dollar under-actuated gripper design. This 6-DOF system is used as a test platform for sensor and actuator integration for future prototypes.  It is controlled by a Make Controller (based on the ARM architecture), runs RTOS and uses CGI-type commands over Ethernet via an embedded web server. Videos ceiling-mark1.flv Concept video, in a kitchen situation, with a two armed version of the Mark 1 robot running on a ceiling track. Images