Self-balancing and power-assisted payload carrying vehicles using operator-applied force sensing

A hand truck, comprising:

• a frame defining a payload deck and a handle;
• a drive module coupled to the frame;
• two laterally disposed wheels, positioned along a central axis, each wheel coupled to the drive module;
• at least one sensor, coupled to the frame, and configured to detect a value of a force applied to the handle by a user;
• and
• a controller, coupled to the drive module, configured to:
• receive the force value from the at least one sensor, the force value comprising a direction and a magnitude;
• and
• control the drive module to provide an amount of torque to at least one wheel to cause the at least one wheel to rotate in a respective direction as a function of the force magnitude and direction such that the magnitude of measured force applied by the user is not greater than a predetermined threshold value.

A method of operating a hand truck having two laterally disposed wheels positioned along a central axis, the wheels powered by a motor, the hand truck having a center of mass, the method comprising:

• a user setting a static balance point by orienting the hand truck to place the center of mass directly above the central axis;
• and
• subsequent to the setting of the static balance point:
• controlling the motor to provide torque to at least one wheel to maintain the hand truck oriented at the static balance point.

A hand truck, comprising:

• a frame defining a payload deck and a handle;
• a drive module coupled to the frame;
• two laterally disposed wheels, positioned along a central axis, each wheel coupled to the drive module;
• at least one orientation sensor, coupled to the frame, and configured to detect an orientation of the frame;
• and
• a controller, coupled to the drive module and the at least one orientation sensor, configured to:
• receive an indication from a user that the frame is oriented at a static balance point where a center of mass of the hand truck is placed directly above the central axis;
• retrieve and store at least one orientation value from the at least one orientation sensor corresponding to the orientation of the frame at the static balance point;
• and to:
• receive orientation values from the at least one orientation sensor;
• and
• control the drive module to provide an amount of torque to each wheel to cause each wheel to rotate in a respective direction in order to maintain the hand truck oriented at the static balance point, the amount of provided torque determined as a function of the received orientation values and the stored static balance point orientation values.

A method of operating a hand truck having two laterally disposed wheels positioned along a central axis, the hand truck having a center of mass, the method comprising:

• a user setting a static balance point by orienting the hand truck to place the center of mass directly above the central axis;
• and
• subsequent to the setting of the static balance point:
• measuring a force applied by the user to the hand truck, the measured force comprising a direction and a magnitude;
• and
• providing torque to each wheel to cause each wheel to rotate in a respective direction as a function of the measured force direction while maintaining the hand truck oriented at the static balance point and such that the magnitude of measured force applied by the user is kept below a predetermined threshold value.

A hand truck, comprising:

• a frame defining a payload deck and a handle;
• a drive module coupled to the frame;
• two laterally disposed wheels, positioned along a central axis, each wheel coupled to the drive module;
• at least one sensor, coupled to the frame, and configured to detect a value of a force applied to the handle by a user;
• at least one orientation sensor, coupled to the frame, and configured to detect an orientation of the frame;
• and
• a controller, coupled to the drive module, the at least one orientation sensor and the at least one force sensor, configured to:
• receive an indication from a user that the frame is oriented at a static balance point where a center of mass of the hand truck is placed directly above the central axis;
• and
• retrieve and store at least one orientation value from the at least one orientation sensor corresponding to the orientation of the frame at the static balance point;
• the controller further configured to:
• receive force values from the at least one sensor, each force value comprising a direction and a magnitude;
• receive orientation values from the at least one orientation sensor;
• and
• control the drive module to provide an amount of torque to each wheel to cause each wheel to rotate in a respective direction in order maintain the magnitude of measured force applied by the user to below a predetermined threshold value while maintaining the hand truck oriented at the static balance point, the amount of provided torque determined as a function of:
• the received force values magnitudes and directions;
• the received orientation values;
• and
• the stored static balance point orientation values.

A method of operating a hand truck having two laterally disposed wheels positioned along a central axis, each wheel powered by a respective motor, the hand truck having a center of mass, the method comprising:

• repeatedly tilting the hand truck fore and aft to repeatedly move the center of mass fore and aft over the central axis;
• detecting, while repeatedly tilting, when the center of mass is directly above the central axis and setting that point as a static balance point;
• and
• controlling each motor to provide torque to the respective wheel to maintain the hand truck at the static balance point.

A hand truck, comprising:

• a frame defining a payload deck and a handle;
• a drive module coupled to the frame;
• two laterally disposed wheels, positioned along a central axis, each wheel coupled to the drive module, each wheel powered by a respective motor;
• at least one orientation sensor, coupled to the frame, and configured to detect an orientation of the frame;
• and
• a controller, coupled to the drive module and the at least one orientation sensor, configured to:
• receive orientation values from the at least one orientation sensor;
• determine, from the received orientation values, when the frame is oriented at a static balance point where a center of mass of the hand truck is placed directly above the central axis;
• and
• store at least one orientation value from the at least one orientation sensor corresponding to the orientation of the frame at the static balance point;
• and
• to:
• receive orientation values from the at least one orientation sensor;
• and
• control the drive module to provide an amount of torque to each wheel to cause each wheel to rotate in a respective direction in order to maintain the hand truck oriented at the static balance point, the amount of provided torque determined as a function of the received orientation values and the stored static balance point orientation values.

A method of operating a hand truck having two laterally disposed wheels positioned along a central axis, each wheel powered by a respective motor, the motor powered by a battery and the hand truck having a center of mass, the method comprising:

• detecting a power level of the battery;
• comparing the detected battery power level to a predetermined threshold and determining whether the detected level is less than the predetermined threshold;
• and
• subsequent to a determination that the detected level is less than the predetermined threshold:
• controlling each motor to provide torque to the respective wheel in order to move the center of mass forward of the central axis to place a deck of the hand truck on a surface.

A hand truck, comprising:

• a frame defining a payload deck and a handle;
• a drive module coupled to the frame, the drive module comprising at least one motor and at least one battery coupled to the at least one motor;
• two laterally disposed wheels, positioned along a central axis, each wheel coupled to the at least one motor;
• at least one battery power sensor, coupled to the at least one battery, and configured to detect a power value of a respective battery;
• at least one orientation sensor, coupled to the frame, and configured to detect an orientation of the frame;
• and
• a controller, coupled to the drive module, the at least one orientation sensor and the at least one battery power sensor, configured to:
• receive orientation values from the at least one orientation sensor;
• receive battery power values from the at least one battery power sensor;
• and
• when a received at least one battery power level is at or below a predetermined minimum threshold value, control the drive module to provide an amount of torque to each wheel to cause each wheel to rotate in a respective direction in order to place the deck on a ground surface,
• wherein the amount of provided torque is determined as a function of the received orientation values.