of production include the price (US$5,000 at launch), and the learning curve in learning to balance on a Segway which has led to notable accidents involving Usain Bolt, George W. Bush and the Segway Company owner Jimi Heselden. While the Segway has remained popular for security and tourism, electric scooters have been more popular for personal mobility. Products At the end of production in 2020, Segway was selling these five self-balancing scooters: Professional Segway i2 SE (professional self-balancing scooter for use in warehouses and other locations) Segway x2 SE (ruggedised self-balancing scooter for use on most challenging terrain) Segway Robot (autonomous robot based on the Segway miniPro) Consumer Ninebot by Segway E+ (self-balancing scooter for general use) Ninebot by Segway miniPro (smaller self-balancing scooter for general use, controlled by a 'knee control bar') Technology The dynamics of the Segway PT are similar to a classic control problem, the inverted pendulum. It uses brushless DC electric motors in each wheel powered by lithium-ion batteries with balance achieved using tilt sensors, and gyroscopic sensors developed by BAE Systems' Advanced Technology Centre. The wheels are driven forward or backward as needed to return its pitch to upright. Usage In 2011, the Segway i2 was being marketed to the emergency medical services community. In 2018, the police of Stockholm adopted Segways as a permanent transportation method for the patrollers of the old town. The Segway miniPro is also available to be used as the mobility section of a robot. Disability Rights Advocates for Technology worked to supply Segway PTs to veterans who had trouble walking. (Segway Inc. cannot market its devices in the US as medical devices. Kamen sold the intellectual property rights for medical purposes to Johnson & Johnson, makers of the iBOT, a self-balancing wheelchair). The maximum speed of the Segway PT is . The product is capable of covering on a fully charged lithium-ion battery, depending on terrain, riding style, and the condition of the batteries. The U.S. Consumer Product Safety Commission does not have Segway-specific recommendations but does say that bicycle helmets are adequate for "low-speed, motor-assisted" scooters. See also Scooter (motorcycle) Segway polo Jonathan Gleich References External links Personal transporters Vehicles introduced in 2001 American inventions 2000s fads and trends Battery electric vehicles Electric two-wheel vehicles Mobility devices Articles containing video clips