Personal mobility vehicles and methods

A vehicle for carrying a payload including a user, the vehicle comprising:

• a. a platform which supports the user;
• b. a ground-contacting module, to which the platform is mounted, which propels the user in desired motion over an underlying surface;
• c. a motorized drive arrangement, coupled to the ground-contacting module;
• the drive arrangement, ground-contacting module and payload comprising a system being unstable with respect to tipping when the motorized drive is not powered;
• the motorized drive arrangement causing, when powered, automatically balanced operation of the system wherein the vehicle has a present velocity and a maximum operating velocity, determined by a requirement of acceleration to maintain balance and, in operation, has a balancing margin determined by the difference between the maximum operating velocity and the present velocity of the vehicle;
• d. a balancing margin monitor, coupled to the ground-contacting module, for generating a signal characterizing the balancing margin;
• and
• e. an alarm, coupled to the balancing margin monitor, for receiving the signal characterizing the balancing margin and for warning when the balancing margin falls below a specified limit.