Automatic transmissions and methods therefor
View Patent ↗Systems and methods for controlling transmissions and associated vehicles, machines, equipment, etc., are disclosed. In one case, a transmission control system includes a control unit configured to use a sensed vehicle speed and a commanded, target constant input speed to maintain an input speed substantially constant. The system includes one or more maps that associate a speed ratio of a transmission with a vehicle speed. In one embodiment, one such map associates an encoder position with a vehicle speed. Regarding a specific application, an automatic bicycle transmission shifting system is contemplated. An exemplary automatic bicycle includes a control unit, a shift actuator, various sensors, and a user interface. The control unit is configured to cooperate with a logic module and an actuator controller to control the cadence of a rider. In one embodiment, a memory of, or in communication with, the control unit includes one or more constant cadence maps that associate transmission speed ratios with bicycle speeds.
1. A bicycle comprising:
a transmission;
a system for automatically shifting the transmission, the system comprising:
a speed sensor configured to detect a speed of the bicycle;
a control unit configured to receive input from the speed sensor;
a data input interface configured to provide cadence data to the control unit, said cadence data indicative of a desired, constant input pedaling speed;
a memory in communication with the control unit, the memory having stored therein one or more data structures correlating bicycle speeds with speed ratios;
wherein the control unit is configured to determine from said data structures a target speed ratio based on the speed of the bicycle and the cadence data, and
an actuator configured to selectively tilt a power transmitting ball of the transmission, in communication with the control unit, the actuator configured to adjust a speed ratio of the transmission to be substantially equal to the determined target speed ratio.
2. The bicycle of claim 1 , wherein the data input interface comprises a display and at least one button.
3. The bicycle of claim 2 , wherein the data input interface is mounted on a handlebar of the bicycle.
4. The bicycle of claim 1 , further comprising a position sensor configured to provide an indication of a position of the actuator.
5. The bicycle of claim 4 , wherein the data structures have a speed ratio data structure and a bicycle speed data structure.
6. The bicycle of claim 1 , wherein the ball-planetary transmission comprises a shift rod, the shift rod operably coupled to the actuator.
7. An automatic shifting bicycle system comprising:
a transmission having a shift rod;
an actuator operably coupled to the shift rod;
a control unit in communication with the actuator;
a memory in communication with the control unit, the memory storing at least one table correlating a position of the actuator to the transmission ratio, wherein the table contains data that correlates a position of the shift rod to a transmission ratio and data that correlates the position of the shift rod to a cadence level, and wherein the control unit communicates a desired transmission ratio to the actuator based at least in part on the table.
8. The system of claim 7 , wherein the processor is configured to determine a target speed ratio for the transmission.
9. The system of claim 7 , further comprising a speed sensor configured to detect a speed of the transmission, the speed sensor in communication with the processor.
10. The system of claim 7 , wherein the actuator is adapted to adjust the transmission ratio based at least in part on the target transmission ratio.
11. The system of claim 10 , wherein the actuator is configured to rotate the shift rod to adjust the transmission ratio.
12. The system of claim 7 , further comprising a user interface in communication with the processor.
13. The system of claim 12 , wherein the user interface is configured to receive a command from an operator, the command indicative of a desired operating condition.
14. The system of claim 13 , wherein the user interface comprises at least one button.
15. The system of claim 14 , wherein the user interface comprises a display.
16. The system of claim 13 , wherein the desired operating condition is a desired cadence level.
17. The system of claim 13 , wherein the desired operating condition is a speed of the bicycle.
18. The system of claim 7 , further comprising an encoder in communication with the processor, the encoder configured to indicate a position of the shift rod.