Method and system for transmission utilizing centrifugal clutch to overcome transmission tooth-butt

A method for controlling a vehicular automated transmission system to overcome a tooth butt condition, the automated transmission system including an internal combustion engine having an engine output member, a multiple speed change gear transmission having an input shaft, a centrifugal friction clutch for drivingly connecting said engine output member to said input shaft, a throttle responsive to manually requesting of a degree of engine fueling, a system controller receiving input signals including two or more of signals of (i) engine speed, (ii) throttle position, (iii) engaged transmission ratio, (iv) input shaft speed, (v) vehicle speed, (vi) a position of jaw clutch members, and (vii) shift signals indicative of attempting to shift the transmission into gear, and the system controller having at least one mode of operation for selectively controlling engine fueling to control at least one of engine speed and engine torque, and the system controller processing said signals according to logic rules to issue command output signals to system actuators including at least said engine controller, said method comprising the steps of:

• (a) sensing certain tooth butt constituent conditions;
• (b) establishing the occurrence of the tooth butt condition based on the tooth butt constituent conditions;
• c) imposing automatic control of the engine by the controller with the occurrence of the tooth butt condition;
• d) at least periodically checking the tooth butt constituent conditions after the occurrence of the tooth butt condition and ending automatic control of the engine by the controller if any of the tooth butt constituent conditions are not satisfied;
• e) automatically increasing the engine speed at a first ramp-rate under control of the controller until one of a first target engine speed and a first target elapsed ramp-up time is reached;
• f) automatically decreasing the engine speed to an idle speed upon reaching one of the first target engine speed and the first target elapsed ramp-up time under control of the controller;
• g) if the transmission remains in a tooth butt condition after reducing the engine speed to idle, again automatically increasing the engine speed under control of the controller at a second ramp-rate up to a maximum established by one of a second target engine speed and a second target elapsed ramp-up time;
• h) automatically decreasing the engine speed to an idle speed upon reaching one of the second target engine speed and the second target elapsed ramp-up time under control of the controller;
• and
• i) releasing automatic control of the engine by the controller.

A control system for controlling a vehicular automated transmission system to overcome a tooth butt condition, the automated transmission system including an internal combustion engine having an engine output member, a multiple speed change gear transmission having an input shaft, a centrifugal friction clutch for drivingly connecting said engine output member to said input shaft, a throttle responsive to manually requesting of a degree of engine fueling, a system controller receiving input signals including two or more of signals of (i) engine speed, (ii) throttle position, (iii) engaged transmission ratio, (iv) input shaft speed, (v) vehicle speed, (vi) a position of jaw clutch members, and (vii) shift signals indicative of attempting to shift the transmission into gear, and the system controller having at least one mode of operation for selectively controlling engine fueling to control at least one of engine speed and engine torque, and the system controller processing said signals according to logic rules to issue command output signals to system actuators including at least said engine controller, said control system comprising logic rules effective for:

• (a) sensing certain tooth butt constituent conditions;
• (b) establishing the occurrence of the tooth butt condition based on the tooth butt constituent conditions;
• c) imposing automatic control of the engine by the controller with the occurrence of the tooth butt condition;
• d) at least periodically checking the tooth butt constituent conditions after the occurrence of the tooth butt condition and ending automatic control of the engine by the controller if any of the tooth butt constituent conditions are not satisfied;
• e) automatically increasing the engine speed at a first ramp-rate under control of the controller until one of a first target engine speed and a first target elapsed ramp-up time is reached;
• f) automatically decreasing the engine speed to an idle speed upon reaching one of the first target engine speed and the first target elapsed ramp-up time under control of the controller;
• g) if the transmission remains in a tooth butt condition after reducing the engine speed to idle, again automatically increasing the engine speed under control of the controller at a second ramp-rate up to a maximum established by one of a second target engine speed and a second target elapsed ramp-up time;
• h) automatically decreasing the engine speed to an idle speed upon reaching one of the second target engine speed and the second target elapsed ramp-up time under control of the controller;
• i) releasing automatic control of the engine by the controller.