Control system and method thereof for multispeed transmission

An electro-hydraulic control system for a multispeed transmission, comprising:

• a controller for operably controlling the transmission;
• a fluid source for supplying hydraulic fluid;
• a plurality of torque-transmitting mechanisms being operably selected between an applied and an unapplied state to achieve a plurality of ranges including at least one reverse, a neutral, and a plurality of forward ranges, wherein in any one of the plurality of forward ranges only two of the plurality of torque-transmitting mechanisms are in the applied state;
• a plurality of trim systems being in electrical communication with the controller and in fluid communication with the fluid source, wherein each of the plurality of trim systems includes a pressure control solenoid and a trim valve;
• a plurality of shift valves each of which is disposed in fluid communication with the fluid source and configured to move between a stroked position and a de-stroked position, the plurality of shift valves including at least a first shift valve, a second shift valve and a third shift valve;
• a boost plug disposed in direct fluid communication with a first torque-transmitting mechanism of the plurality of torque-transmitting mechanisms, a first trim system of the plurality of trim systems, and the second shift valve, the first trim system including a first pressure control solenoid and a first trim valve;
• wherein:
• in at least one of the plurality of forward ranges, hydraulic fluid from the fluid source does not fluidly couple the boost plug with the second shift valve, and the first pressure control solenoid pressurizes the boost plug and first trim valve to a stroked position;
• in another forward range of the plurality of forward ranges, hydraulic fluid from the fluid source fluidly couples the boost plug with the second shift valve, and the hydraulic fluid bypasses the boost plug such that only the first trim valve moves to the stroked position.

An electro-hydraulic control system for a multispeed transmission, comprising:

• a controller for operably controlling the transmission;
• a fluid source for supplying hydraulic fluid at a main pressure;
• a plurality of torque-transmitting mechanisms being operably selected between an applied and an unapplied state to achieve a plurality of ranges;
• a trim system being in electrical communication with the controller and in fluid communication with the fluid source, wherein the trim system comprises a pressure control solenoid and a trim valve;
• a plurality of shift valves each of which is disposed in fluid communication with the fluid source and configured to move between a stroked position and a de-stroked position, the plurality of shift valves including at least a first shift valve, a second shift valve and a third shift valve;
• a boost valve disposed in fluid communication with the trim system, the second shift valve, and at least two of the plurality of torque-transmitting mechanisms, where the boost valve is hydraulically controlled between a first position and a second position;
• wherein, when one of the at least two torque-transmitting mechanisms is in its applied state, a fluid pressure applying the one torque-transmitting mechanism is below main pressure and hydraulically maintains the boost valve in its first position.