Text this: CONTACT FORCE AND POSITION CONTROL IN CONSTRAINED ROBOTS : THEORY AND EXPERIMENTS

   _____     ___     _    _    __   __     _____  
  / ___//   / _ \\  | || | ||  \ \\/ //   / ___// 
  \___ \\  | / \ || | || | ||   \ ` //    \___ \\ 
  /    //  | \_/ || | \\_/ ||    | ||     /    // 
 /____//    \___//   \____//     |_||    /____//  
`-----`     `---`     `---`      `-`'   `-----`