Mobile robot having an improved suspension system

A mobile robot configured to drive on a surface with irregularities, comprising:

• a chassis having a front end facing a forward direction of travel of the mobile robot, a back end, a first side, and a second side;
• a first drive wheel rigidly affixed to the chassis proximate the first side and interconnected to at least one motor to propel the first drive wheel;
• a second drive wheel rigidly affixed to the chassis proximate the second side and interconnected to the at least one motor to propel the second drive wheel;
• a first caster assembly rigidly affixed to the chassis proximate the front end of the chassis;
• wherein the first caster assembly includes a first swivel mechanism to which a first caster wheel is rotatably affixed via a rigid interconnection member to rotate about a first swivel axis;
• and
• a second caster assembly rigidly affixed to the chassis proximate the back end of the chassis;
• wherein the second caster assembly includes a second swivel mechanism to which a second caster wheel is rotatably affixed via a compliant interconnection member to rotate about a second swivel axis;
• a laser-radar sensor located proximate the front end of the chassis configured to provide sensor data to a robot controller for navigation of the mobile robot;
• wherein when the at least one motor propels the first and second drive wheels, thereby causing the mobile robot to drive on the surface, the compliant interconnection member of the second caster assembly absorbing the irregularities in the surface and the rigid interconnection member of the first caster assembly maintaining the front end of the chassis level with the surface to provide a consistent scan plane for the laser-radar sensor.