Abstract: An electronic data link that services components of the vehicle including components other than the engine and an electronic engine management system that services the engine operate in different data formats and are interfaced by a special electronic module that provides translation services for accomplishing bi-directional through-transmission of data between them. The module has programmable memory with different levels of security and can detect the absence of a vehicle speed sensor at incipient vehicle launch. The speed sensor serves both the data link and the electronic engine management system through the special module.

Abstract: In an automatic draft control system for positioning a hitch, velocity feedback loop techniques are employed to control the rate of movement of the hitch. When the system is operating in an open loop position control mode, a switch mounted on a tractor fender enables an operator to manually control raising/lowering of the hitch for the purpose of attaching an implement. Hitch position is sensed and a microprocessor calculates the first derivative of the hitch position signal to determine actual hitch velocity. The actual velocity is subtracted from a desired velocity value to obtain a velocity error signal. The error signal is subjected to an integral control algorithm and the integrated value is used to energize raise or lower solenoids controlling a valve which raises or lowers the hitch. When the actual hitch velocity is equal to or greater than the desired hitch velocity, the integrated value is saved. When the next raise/lower sequence is initiated the integrator is reset to the saved value.

Abstract: Microprocessor controlled automatic power control for adjusting the engine power setting in an engine-transmission power train in which the transmission drive reduction is variable in ratio, by step change or continuously so, such as for use in farm tractors. The microprocessor control monitors the position of this automatically moving lever and the desired transmission output speed to keep the setting adjusted so that engine power is set, within a deadband, to maintain a desired engine speed preferably resulting in minimum fuel consumption or in maintaining constant transmission output speed. Preferably, the microprocessor has a higher priority primary function of also automatically adjusting the transmission drive reduction ratio, for the same purpose but with higher sensitivity. The power control lever is specifically designed to automatically return the power setting to manual control as soon as the operator grabs the handle.

Abstract: A microprocessor controlled drive train having an engine-connected variable ratio speed transmission and a load-connected range gear transmission connected by a mid-mounted clutch disposed therebetween has an automatic clutch control mode of operation, with the clutch disengaged and the range transmission in gear to complete a shift, wherein the speeds of the clutch sides are synchronized before engagement by appropriately varying the ratio of the speed transmission, thereby eliminating shift shock. This automatic clutch control mode is preferably employed in combination with operating modes which control both the speed transmission ratio and engine throttle to maintain fuel efficient operation.

Abstract: Engine monitor/control microprocessor primarily effective to automatically adjust the engine power setting in a transmission power train in which the transmission drive reduction is variable in ratio, by step change or continuously so, such as for use in farm tractors. The microprocessor adjusts the position of the setting so that engine power set at all levels is produced at the right brake specific fuel consumption for substantially minimum pounds of fuel per horsepower hour, or within a band width thereof if not all that sensitive. Preferably, the microprocessor has a higher priority primary function of also automatically adjusting the transmission drive reduction ratio, for the same purpose but with high sensitivity.

Abstract: The present invention provides a method and system for monitoring the rotor speed of the harvesting rotors of a cotton harvester. The inventive rotor speed monitor determines the rotational speed of each individual rotor. The individual speeds of the rotors are combined and an average rotor speed computed. The individual rotor speed is then compared with the average speed for the combined rotors. An alarm is provided to alert the operator whenever the rotational speed of a given rotor differs by a predetermined amount from the average rotational speed for the combined rotors. The invention rotor speed monitor can provide an early indication of rotor malfunction and also detours false signals generated by the harvester rotors deceleration after completion of the harvesting operation on a cotton row.

Abstract: Transmission monitor/control microprocessor primarily effective to automatically adjust the effective drive reduction ratio of a power train of the type in which such transmission is variable by step change or continuously, such as for use in farm tractors. The microprocessor adjusts the drive reduction ratio so that engine power at all levels is produced at a minimum specific fuel consumption.

Abstract: A control valve assembly (10) is provided for controlling a hydrostatic transmission including a fluid pump having a variable swashplate, a source of control fluid under pressure, and a servo system responsive to the control fluid for varying the swashplate of the fluid pump. The control valve includes a valve body (12), first (26) and second (28) fluid chambers disposed in the valve body, a first fluid passageway (30) disposed in the valve body for directing pressurized control fluid to the first and second fluid chambers and a valve member (16) located in the valve body for controlling the flow of control fluid to the servo system. The pressurized fluid in the first fluid chamber acts on the valve member to bias the valve member in a first direction and the pressurized fluid in the second chamber acts on the valve member to bias the valve member in the second direction opposite the first direction.

Abstract: A control system for a hydrostatic transmission is disclosed of the type including an engine driven fluid pump and a fluid motor. The control system includes a main control operable in response to an electrical command signal to vary the displacement of the pump, and a command signal generator for generating the command signal. The anti-stall control includes means for comparing electrical signals representative of engine speed and a reference speed, and generating an electrical anti-stall signal representative of the maximum percentage of commanded pump displacement which is permissible without causing the engine to drop below the reference speed. The anti-stall control includes means for electrically multiplying the anti-stall signal and the command signal, downstream of the shaping and rate limiting circuits. The invention provides a simple, inexpensive anti-stall control which can be adjusted to have the maximum possible gain (responsiveness) without inducing circuit instability.

Abstract: A steering control system is disclosed for use on a dual path, hydrostatic drive vehicle. The steering control system includes a steering signal generator, the steering signal representing commanded steering ratio and direction. The system senses vehicle direction and steering direction and generates an electrical switch signal having a first or second condition, depending upon which transmission must have its speed reduced to achieve the desired vehicle orientation. The steering signal and the main speed command signal are multiplied to generate a speed modification signal and an electrical switch transmits the modification signal to one transmission or the other depending upon whether the switch signal is in the first or second condition. The disclosed steering system permits use of a T-handle control, for both speed and steering, such that vehicle orientation may be maintained generally perpendicular to handle orientation for both forward and reverse vehicle travel.

Abstract: An electro-hydraulic control for a hydrostatic transmission including a variable displacement hydraulic pump, a fixed displacement hydraulic motor, and fluid operable strokers to vary the displacement of the pump. The electro-hydraulic control is in series between the charge pump and the standard manual controller and determines the pressure of the charge fluid ported to the standard controller. The electro-hydraulic control includes a spool biased toward a first position to port fluid from the charge pump to the standard controller, and biased toward a second position to relieve to tank the pressure of fluid ported to the manual controller. The biasing toward the second direction is accomplished, in part, by pressure in a fluid chamber exerting a biasing force on the spool, the fluid chamber being in communication with drain through a variable orifice which is variable in response to a pressure command signal.

Abstract: A control including a control valve and an override valve for use with a variable displacement pump or motor unit having a pair of strokers into and out of which fluid must be directed to vary the displacement of the unit. The control valve ports fluid from a high pressure source to a first control passage and from a second control passage to a low pressure source, reverses said flow, and terminates said flow. The override valve is interposed between the control passages and the strokes and defines a pair of override passages therein used to direct fluid from one control passage to one stroker and from the other stroker to the other control passage. The override valve is selectively movable between a first position directing such flow therethrough and a second position in which such flow is terminated between the control passages and the strokers.

Abstract: An electro-hydraulic control for a hydrostatic transmission including a variable displacement hydraulic pump and fluid operable servos to vary the displacement of the pump. The electro-hydraulic control is in series between the charge pump and the standard manual controller and determines the maximum pressure of the charge fluid ported to the standard controller. The electro-hydraulic control includes a spool biased toward a first position to port fluid from the charge pump to the standard controller, and biased toward a second position to relieve to tank the pressure of fluid ported to the manual controller. The biasing toward the second direction is accomplished, in part, by pressure in a fluid chamber exerting a biasing force on the spool, the fluid chamber being in communication with drain through a variable orifice which is variable in response to a pressure command signal.

Abstract: A control valve for a variable displacement pump or motor. The valve includes a pair of solenoids which are independently actuatable to port relatively high pressure fluid to their respective servo motor. A shuttle valve actuated by the high pressure fluid is used to simultaneously port the fluid from the other servo motor to a low pressure fluid source. A manual valving system is also provided having a pair of balls each biased into engagement with a seat to seal a passage to one of the servo motors. Movement of either ball off of its seat allows high pressure to flow to the respective servo motor. The high pressure fluid actuates the shuttle valve to port fluid from the other servo motor to the low pressure fluid source.