Abstract: An electrically powered vehicle wherein the electric power may be provided by an auxiliary electric motor with power assist being determined by a manual force applied by an operator for manually propelling the vehicle. The vehicle control includes a method for determining when the vehicle is being started from a stop and for providing a gradual application of electric power assist during such start-up. In addition, if the operator calls for an abrupt change in power assist, the actual power assist is applied only gradually to provide smoother operation. The system also has self-checking functions and the electric power assist is disabled in response to certain types of failures. However, the operator is warned in advance that the power will be shut down so as to avoid emergency situations. The self-checking provides an arrangement for checking when the speed sensor is inoperative by sensing certain output characteristics of the speed sensor and the force application.

Abstract: An electrically power assisted, manually operated vehicle, such as a bicycle, that includes a force sensor for varying the amount of power assist by an electrical motor in response to the manual force input. In addition, a vehicle speed sensor is incorporated for sensing vehicle speed. An abnormality condition detector detects both the outputs from the force sensor and the vehicle speed sensor and indicates an abnormality and discontinues the supply of electrical power to the electric motor in the event of a discrepancy in the outputs of the sensors.

Abstract: A speed control for a wheeled vehicle which is propelled by a motive device that has a speed proportional to the vehicle speed, and a power output control to control the speed of the motive device. A first signal generator generates a signal proportional to a desired vehicle speed. A second signal generator generates a signal proportional to the actual vehicle speed. A comparator compares the signals to detect any difference, and controls an actuator to adjust the power output control to tend to eliminate the difference. The actual speed will thereby tend to approach the desired speed. The first signal generator can, if desired, be operated by the occupant of the vehicle as part of his propulsive effort, for example by driving a bicycle chain drive. The speed control also can have provisions to continue operations at a pre-set rate even when the first signal generator may be inactive, and to make appropriate power control settings at start-up and at the beginning of acceleration conditions.