A guidance system for a machine includes one or more guide assemblies. Each guide assembly includes a support member, a lever, an abutment device, a sensor, and a controller. The support member is fixedly coupled to a frame of the machine. The lever is angularly biased away with respect to the support member. The abutment device is coupled to the lever is configured to be abutted and guided on a structure extending along a direction in which the machine moves to modify a roadway surface. The sensor detects a measured angle between the lever and the support member when the abutment device is abutted against the structure. The controller controls an actuation of a steering actuator associated with one or more traction devices of the machine to turn the traction devices based on the measured angle to modify the roadway surface along an extent of the structure.

A paving machine including a modular frame, a plurality of swing legs pivotable relative to the frame, a jacking column secured to each swing leg, a crawler track, a slew gear drive, and angular position transducers for measuring an angular position between the swing leg and the modular frame, and an angular position of the crawler track relative to the jacking column. Feedback from the transducers facilitates maintaining position of the crawler track. The jacking column can include telescoping outer and inner tubes, a vertically oriented hydraulic actuator including a cylinder and a piston operable within the outer and inner tubes, and spaced apart axial bearings coupled to the outer tube and/or the inner tube. The slew gear drive can be secured between the inner tube and a yoke and capable of steering the crawler track under load without lifting the crawler track.

A paving machine including a modular frame, a plurality of swing legs pivotable relative to the frame, a jacking column secured to each swing leg, a crawler track, a slew gear drive, and angular position transducers for measuring an angular position between the swing leg and the modular frame, and an angular position of the crawler track relative to the jacking column. Feedback from the transducers facilitates maintaining position of the crawler track. The jacking column can include telescoping outer and inner tubes, a vertically oriented hydraulic actuator including a cylinder and a piston operable within the outer and inner tubes, and spaced apart axial bearings coupled to the outer tube and/or the inner tube. The slew gear drive can be secured between the inner tube and a yoke and capable of steering the crawler track under load without lifting the crawler track.

The invention relates to a self-propelled construction machine and to a method for controlling a self-propelled construction machine. The construction machine according to the invention has a position-determining device 13 for determining the position of a reference point R on the construction machine in a coordinate system (X, Y, Z) independent of the construction machine. The position-determining device has a navigation satellite system receiver 14 for receiving satellite signals from a global navigation satellite system 15 (GNSS) and a computing unit 16 which is configured so that the position of a reference point (R) on the construction machine and the orientation (ψ) of the construction machine can be determined based on the satellite signals in a coordinate system (X, Y, Z) that is independent of the construction machine. Moreover, the construction machine has a controller 18 which cooperates with the position-determining device 13 configured to adjust the steering angles of the steerable running gears 3, 4, 6 so that the reference point R of the construction machine moves along a set trajectory T. The computing unit 16 of the position-determining device 13 is configured so that, in a control mode in which the control of the construction machine is not based on the satellite signals of the global navigation satellite system 15, the position (x.sub.n, y.sub.n, z.sub.n) of the reference point (R) relating to the construction machine and the orientation (ψ) of the construction machine are determined in the coordinate system (X, Y, Z) that is independent of the construction machine while the construction machine is moving on the basis of a kinematic model 16A implemented in the computing unit 16 of the position-determining device 13 which describes the position (P) of the reference point (R) and the orientation (ψ) in the coordinate system (X, Y, Z) that is independent of the construction machine depending on the steering angles and the speeds of the running gears 3, 4, 6.

The invention relates to a self-propelled construction machine and to a method for controlling a self-propelled construction machine. The construction machine according to the invention has a position-determining device 13 for determining the position of a reference point R on the construction machine in a coordinate system (X, Y, Z) independent of the construction machine. The position-determining device has a navigation satellite system receiver 14 for receiving satellite signals from a global navigation satellite system 15 (GNSS) and a computing unit 16 which is configured so that the position of a reference point (R) on the construction machine and the orientation (ψ) of the construction machine can be determined based on the satellite signals in a coordinate system (X, Y, Z) that is independent of the construction machine. Moreover, the construction machine has a controller 18 which cooperates with the position-determining device 13 configured to adjust the steering angles of the steerable running gears 3, 4, 6 so that the reference point R of the construction machine moves along a set trajectory T. The computing unit 16 of the position-determining device 13 is configured so that, in a control mode in which the control of the construction machine is not based on the satellite signals of the global navigation satellite system 15, the position (x.sub.n, y.sub.n, z.sub.n) of the reference point (R) relating to the construction machine and the orientation (ψ) of the construction machine are determined in the coordinate system (X, Y, Z) that is independent of the construction machine while the construction machine is moving on the basis of a kinematic model 16A implemented in the computing unit 16 of the position-determining device 13 which describes the position (P) of the reference point (R) and the orientation (ψ) in the coordinate system (X, Y, Z) that is independent of the construction machine depending on the steering angles and the speeds of the running gears 3, 4, 6.

A multi-purpose planet planetary exploration rover is provided in this invention, which relates to the field of planet exploration. The multi-purpose planetary exploration rover includes a case body, mounted with a first wheel at left and right sides respectively; and a cantilever, having a front end connected to the case body, a rear end of the cantilever being mounted with a second wheel; wherein the cantilever is rotated or fixed relative to the case body, the second wheel is steered relative to the cantilever, and the first wheel and the second wheel are used to drive the multi-purpose planetary exploration rover. Compared with the prior art, the multi-purpose planetary exploration rover of this invention can effectively explore special geographic locations such as cliffs, volcanic craters, craters and lava caves on alien planets.

A slew drive includes a bushing interfacing with a drive gear. The bushing resists a load from the drive gear. The bushing includes an aluminum bronze alloy with a high strength. A paving machine includes multiple of the slew drives. The slew drives control an angle of a pivot arm and steering of a track. A method of reducing component failure in the paving machine includes determining an angular position error of the slew drive of the track. If the angular position exceeds a tolerance, a rate-of-change of the angular position is found to determine whether the slew drive is rotating. Where the slew drive is not rotating, the slew drive is driven in a reverse direction to unseize the slew drive. A track drive and the slew drive of the pivot are controlled by a control loop. The slew drive may be dithered to steer a trailing pivot.

A milling machine can include a frame; at least two tracks coupled to the frame for propelling the milling machine; first and second hydraulic cylinders configured to steer each of the at least two tracks, respectively; an adjustable hydraulic tie rod extending between the at least two tracks; first and second steering collars coupled to the each of the tracks to move the tracks, wherein the first hydraulic cylinder is coupled to the first steering collar and the second hydraulic cylinder is coupled to the second steering collar, and wherein the adjustable hydraulic tie rod is coupled to both of the steering collars; one or more sensors to determine the positions of the at least two tracks; and a hydraulic steering control system coupled to the first and second hydraulic cylinders and the adjustable hydraulic tie rod and configured to vary a steering mode of the at least two tracks between a parallel steering mode and an Ackerman steering mode, wherein if one of the one or more sensors fails, the hydraulic steering control system defaults to move the at least two tracks into the Ackerman steering mode.

A milling machine can include a frame; at least two tracks coupled to the frame for propelling the milling machine; first and second hydraulic cylinders configured to steer each of the at least two tracks, respectively; an adjustable hydraulic tie rod extending between the at least two tracks; first and second steering collars coupled to the each of the tracks to move the tracks, wherein the first hydraulic cylinder is coupled to the first steering collar and the second hydraulic cylinder is coupled to the second steering collar, and wherein the adjustable hydraulic tie rod is coupled to both of the steering collars; one or more sensors to determine the positions of the at least two tracks; and a hydraulic steering control system coupled to the first and second hydraulic cylinders and the adjustable hydraulic tie rod and configured to vary a steering mode of the at least two tracks between a parallel steering mode and an Ackerman steering mode, wherein if one of the one or more sensors fails, the hydraulic steering control system defaults to move the at least two tracks into the Ackerman steering mode.

Steering a vehicle in an electronic steering mode of operation that includes a front axle steering system, a rear axle steering system, one or more vehicle environment sensors, and a controller operatively coupled with the front axle steering system, the rear axle steering system, and the vehicle environment sensors. Commanding the vehicle to operate at a desired vehicle speed, detecting a lateral force acting on the vehicle in response to input from the vehicle environment sensors, and determining an actual lateral acceleration of the vehicle and a predicted lateral acceleration of the vehicle from the desired vehicle speed. Determining a lateral acceleration error by comparing the predicted lateral acceleration to the actual lateral acceleration, and determining if the lateral acceleration error exceeds a lateral acceleration limit, then turning both of the front axle steering system and the rear axle steering system to a crab steering correction angle.