A wheel assembly includes a wheel having an axle, and a constant force mechanism coupled to the wheel. The constant force mechanism includes a horizontal support, a horizontal carriage associated with the horizontal support, a vertical support oriented perpendicular with respect to the horizontal support, a vertical carriage associated with the vertical support, and a rigid arm that is pivotally coupled with the horizontal carriage, the vertical carriage, and the axle. The rigid arm is coupled with the vertical carriage at a point intermediate where the rigid arm is coupled with the horizontal carriage and the axle. The horizontal carriage is capable of being urged along the horizontal support, and the vertical carriage is capable of being urged along the vertical support.

A wheel assembly includes a wheel having an axle, and a constant force mechanism coupled to the wheel. The constant force mechanism includes a horizontal support, a horizontal carriage associated with the horizontal support, a vertical support oriented perpendicular with respect to the horizontal support, a vertical carriage associated with the vertical support, and a rigid arm that is pivotally coupled with the horizontal carriage, the vertical carriage, and the axle. The rigid arm is coupled with the vertical carriage at a point intermediate where the rigid arm is coupled with the horizontal carriage and the axle. The horizontal carriage is capable of being urged along the horizontal support, and the vertical carriage is capable of being urged along the vertical support.

A suspension control system can include a chassis and one or more wheel assemblies. One or more suspension assemblies can be respectively coupled to the one or more wheel assemblies. A computing system can be communicatively coupled to one or more position sensors and one or more orientation sensors. The computing system can be configured to actuate the actuator of the one or more suspension assemblies to define a stroke, determine a default stroke position based on data from the one or more position sensors, and define a default position of the chassis based on data from the one or more orientation sensors.

A suspension control system can include a chassis and one or more wheel assemblies. One or more suspension assemblies can be respectively coupled to the one or more wheel assemblies. A computing system can be communicatively coupled to one or more position sensors and one or more orientation sensors. The computing system can be configured to actuate the actuator of the one or more suspension assemblies to define a stroke, determine a default stroke position based on data from the one or more position sensors, and define a default position of the chassis based on data from the one or more orientation sensors.

A mobile robot configured to drive on a surface with irregularities, comprising: a chassis having a front end facing a forward direction of travel, a back end, a first side, and a second side. There is a first drive wheel rigidly affixed to the chassis proximate the first side and interconnected to a motor to propel it. There is a second drive wheel rigidly affixed to the chassis proximate the second side and interconnected to a motor to propel it. A first caster assembly is rigidly affixed to the chassis proximate the front end and includes a first caster wheel configured to rotate about a first swivel axis. A second caster assembly is rigidly affixed to the chassis proximate the back end and includes a second caster wheel configured to rotate about a second swivel axis and it includes a compliant member to absorb the irregularities.

A mobile robot configured to drive on a surface with irregularities, comprising: a chassis having a front end facing a forward direction of travel, a back end, a first side, and a second side. There is a first drive wheel rigidly affixed to the chassis proximate the first side and interconnected to a motor to propel it. There is a second drive wheel rigidly affixed to the chassis proximate the second side and interconnected to a motor to propel it. A first caster assembly is rigidly affixed to the chassis proximate the front end and includes a first caster wheel configured to rotate about a first swivel axis. A second caster assembly is rigidly affixed to the chassis proximate the back end and includes a second caster wheel configured to rotate about a second swivel axis and it includes a compliant member to absorb the irregularities.

A wheel assembly includes a constant force mechanism and a wheel coupled to the constant force mechanism. The wheel is displaceable in at least one dimension, and the constant force mechanism imparts a substantially constant force on the wheel in the dimension. In one aspect, the wheel is displaceable in a first regime and a second regime. For a wheel displacement in the first regime, the constant force mechanism imparts a substantially constant force on the wheel, and for a wheel displacement in the second regime, the constant force mechanism imparts a variable force on the wheel. The variable force can be linear or non-linear to the magnitude of the displacement in the second regime and is equal to or greater than the substantially constant force.

A wheel assembly includes a constant force mechanism and a wheel coupled to the constant force mechanism. The wheel is displaceable in at least one dimension, and the constant force mechanism imparts a substantially constant force on the wheel in the dimension. In one aspect, the wheel is displaceable in a first regime and a second regime. For a wheel displacement in the first regime, the constant force mechanism imparts a substantially constant force on the wheel, and for a wheel displacement in the second regime, the constant force mechanism imparts a variable force on the wheel. The variable force can be linear or non-linear to the magnitude of the displacement in the second regime and is equal to or greater than the substantially constant force.

A utility vehicle includes a plurality of ground-engaging members, a frame, a powertrain assembly, a front suspension assembly, and a rear suspension assembly. A cargo bed may be supported by the frame at the rear of the vehicle. The vehicle also includes an operator seat and at least one passenger seat positioned within an operator area. In one embodiment, the vehicle includes doors to enclose the operator area.

A utility vehicle includes a plurality of ground-engaging members, a frame, a powertrain assembly, a front suspension assembly, and a rear suspension assembly. A cargo bed may be supported by the frame at the rear of the vehicle. The vehicle also includes an operator seat and at least one passenger seat positioned within an operator area. In one embodiment, the vehicle includes doors to enclose the operator area.