Method and apparatus for skip shifting in a power transmission

A control system for a transmission in a work vehicle including an engine and driven wheels, the transmission being coupled between the engine and the driven wheels and including a plurality of gears and associated clutches, the clutches engageable in predetermined combinations by an actuating circuit to define transmission gear ratios between an output speed of the engine and an output speed of the transmission, the control system comprising:

• an operator-actuated input device for commanding upshifts and downshifts of the transmission, the input device having an upshift position and a downshift position, the input device configured to generate an upshift signal and a downshift signal in response to actuation of the input device into the upshift position and the downshift position, respectively;
• a memory circuit for storing a plurality of independent skip shift values, each skip shift value stored in association with a particular gear ratio;
• and
• a control circuit coupled to the input device and the memory circuit, the control circuit configured to receive the upshift and the downshift signals from the input device, and to selectively engage the clutches to upshift and to downshift the transmission in response to the upshift signal and the downshift signal, respectively, the upshifts and downshifts occurring at predetermined shift rates, wherein the transmission is shifted to provide a current gear ratio;
• wherein the control circuit determines a commanded gear ratio based upon the upshift and downshift signals received from the input device and, when the commanded gear ratio differs from the current gear ratio by more than a predetermined number of gear ratios, accesses the memory circuit to determine the skip shift value associated with the current gear ratio and selectively engages the clutches to skip shift from the current gear ratio to the commanded gear ratio by a number of gear ratios determined by the accessed skip shift value.

A control system for a transmission in a work vehicle including an engine and driven wheels, the transmission being coupled between the engine and the driven wheels and including a plurality of gears and associated clutches, the clutches engageable in predetermined combinations by an actuating circuit to define transmission gear ratios between an output speed of the engine and an output speed of the transmission, the control system comprising:

• actuating means for commanding upshifts and downshifts of the transmission;
• memory means for storing a plurality of independent skip shift values, each skip shift value stored in association with a particular gear ratio;
• first control means for selectively engaging the clutches to upshift and downshift the transmission to provide a current gear ratio as commanded by the actuating means, the upshifts and downshifts of the transmission occurring at predetermined shift rates;
• and
• second control means for determining a commanded gear ratio for the transmission and, when the commanded gear ratio differs from the current gear ratio by more than a predetermined number of gear ratios, accessing the memory means to determine the skip shift value associated with the current gear ratio and selectively engaging the clutches to skip shift from the current gear ratio to the commanded gear ratio by a number of gear ratios determined by the accessed value.

A method of controlling a transmission in a work vehicle including an engine and driven wheels, the transmission being coupled between the engine and the driven wheels and including a plurality of gears and associated clutches, the clutches being engageable in predetermined combinations by an actuating circuit to define transmission gear ratios between an output speed of the engine and an output speed of the transmission, the method comprising:

• storing a plurality of independent skip shift values in a memory, each skip shift value stored in association with a particular gear ratio of the transmission;
• actuating an input device to command shifts of the transmission;
• selectively engaging the clutches to shift the transmission to provide a current gear ratio as commanded by the input device, the shifts occurring at predetermined shift rates;
• determining a commanded gear ratio based on the input device actuations;
• and
• comparing the commanded gear ratio to the current gear ratio and, when the commanded gear ratio differs from the current gear ratio by more than a predetermined number of gear ratios, accessing the memory to determine the skip shift value associated with the current gear ratio and selectively engaging the clutches to skip shift from the current to the commanded gear ratio by a number of gear ratios determined by the accessed skip shift value.