Caterpillar Tractor Co.

Caterpillar Inc.

Catepillar Inc.

Ronald D Brown

Michael G Seil

Matthew E Meiser

James D Waters, Jr

Billy L Stolin

A traction control system for a machine having two driven wheels is disclosed. Braking mechanisms controllably apply braking forces to each of the driven wheels. Transducers produce an actual speed signal having a value proportional to the rotational velocity of each driven wheel. A microprocessor produces a desired speed signal having a value representative of a desired rotational velocity of each driven wheel, and an error signal representative of the difference between the values of the desired and actual speed signals. The microprocessor additionally multiplies the error signal by a gain value and produces a braking command signal to the braking mechanism to apply braking forces to a slipping wheel. The present invention provides the advantage of modifying the gain value based on machine operating conditions in order to achieve good performance.

Method and apparatus for modifying the feedback gains of a traction

A method for reducing the brake pressure commanded by a traction control system of a machine is disclosed. The method includes the steps of estimating the instantaneous heat energy associated with an applied brake, estimating the accumulated heat energy associated with the applied brake during the time period that the brake is applied in response to the instantaneous heat energy; comparing the accumulated heat energy to a maximum allowable heat energy value; and reducing the magnitude of the braking command signal to reduce the applied brake pressure in response to the accumulated heat energy being greater than the maximum allowable heat energy value.

Energy management method for a traction control system

An adaptive welding apparatus has an optical sensing system for detecting the cross sectional configuration of a weld groove by linearly scanning a monochromatic light source across the groove while viewing the reflected light with a raster scan type TV camera. A microprocessor receives signals from the camera, computes the weld groove cross sectional configuration, and calculates the area of the cross section. The angular deviation of the scan path is estimated and corrective calculations are made to compensate for the erroneously large computed area caused by the scan path being skewed from perpendicular to the weld groove. The microprocessor controls at least one of the wire feed speed, travel speed, and voltage to effect proper weld groove fill characteristics in response to the calculated area.

Adaptive welding apparatus having fill control correction for

An apparatus for guiding a welding torch along a weld groove has a visual sensing system for detecting the weld groove cross sectional configuration and relative position of the edges of weld groove. The positional and cross sectional information is assimilated under microprocessor control to actively guide the welding torch through the control of a series of servo motors and adaptively position the welding electrode at an optimal preselected location with the weld groove.

Adaptive welding guidance apparatus

The invention pertains to a welding system having automatic groove tracking and adaptive groove filling capabilities. Data produced by a coordinated laser spot projector (10) and TV-scanner (12) combination is determined to an Intel 8085 computer (28) to provide a substantially continuous analysis of groove locations in a three-axis coordinate system as well as groove depth and area. Location information is fed to an LSI-11 computer (38) to control the tracking function through coordinate axis servo-type drives (46) and to control a fourth-axis or 'swing' function which provides freedom between the welding torch (14) and the optical system (10, 12) which leads the torch by several inches. The groove depth and area information is also fed to the LSI-11 to control the welding parameters, i.e.; deposition rate and voltage and produce the desired weld along the groove.

Adaptive welder with laser TV-scanner

A method of automatically maintaining a selected spacing for a plasma arc cutting torch form a workpiece is disclosed which takes advantage of the fact that at any given setting of a plasma arc power supply the current in the arc varies inversely and the voltage across the arc varies directly in relation to the spacing of the plasma arc torch from the workpiece when new material in the workpiece is presented to the plasma arc at an essentially constant rate and which includes the step of automatically compensating for variations in the rate at which new material is presented to the arc.

Method of and means for spacing control of plasma arc cutting torch

A method of automatically maintaining a selected spacing for a plasma arc torch from a workpiece is disclosed which takes advantage of the fact that at any given setting of a plasma arc power supply the current in the arc varies inversely and the voltage across the arc varies directly in relation to the spacing of the plasma arc torch from the workpiece. According to such method, the current and voltage of the power supply for the torch are sensed in operation, a signal representative of each comparable to the other is generated and one of such signals is inverted with respect to the other of such signals. The signals are then summed with each other and with a third comparable selectively adjustable signal and the difference signal is used to control the spacing of the torch from the workpiece. A preferred embodiment of the control means for practicing the invention is described as included in a commercial plasma arc apparatus and includes means for shutting down the apparatus if an extreme condition occurs such as reaching the end of the workpiece or extinguishment of the arc. Means for protecting the control means during ignition of the arc, for enabling manual control of the plasma arc torch and for interfacing between the control means according to this invention and prior art control means are disclosed.

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Mapleton, IL, United States of America

Ronald D Brown