Safety system, method and computer program for remotely controlled work vehicles
AssigneeHusqvarna AB
InventorsMarcus Idbrant, Kristian Elofsson, Henrik Sihm
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Abstract
The present disclosure relates to a safety system (100) for a remotely operated work vehicle (110). The safety system (100) works by continuously establishing a spatial relationship between the work vehicle (110) and a wireless remote control unit (130), wherein at least part of the information needed to establish the spatial relationship is carried as data in signals. The established spatial relationship is then used to control the work vehicle (110).
Claims14
A safety system for a remotely operated work vehicle, the work vehicle being arranged to receive a first control signal from a wireless remote control unit, the first control signal being arranged to control a drive operation of the work vehicle, wherein the safety system comprises a vehicle unit arranged at the work vehicle and an operator unit arranged at the wireless remote control unit, wherein the operator unit is arranged to transmit at least one signal carrying information relevant for positioning of the wireless remote control unit to the vehicle unit and wherein the vehicle unit is arranged to obtain information relating to a first position of the work vehicle, to determine a spatial relationship between the work vehicle and the wireless remote control unit based on the information relating to a first position of the work vehicle and the information relevant for positioning of the wireless remote control unit, to periodically determine if the spatial relationship meets a predetermined criterion, and to provide a second control signal to the work vehicle;
- the second control signal being arranged to control the drive operation of the work vehicle based on the periodic determination, wherein the work vehicle comprises an ultra-wideband, UWB, transceiver arranged to transmit and receive signals comprising respective time stamps and respective unique IDs, wherein the spatial relationship relates to a first distance between the work vehicle and the wireless remote control unit and wherein in the predetermined criterion comprises the first distance falling within a predetermined distance interval, wherein the vehicle unit is arranged to determine the first distance using two-way ranging time of flight based on a time stamp based on the information relating to a position of the work vehicle that is time stamped at an initial time of the two-way ranging and a time stamp based on a received signal that is time stamped at a finishing time of the two-way ranging.
A method performed in a safety system for a remotely operated work vehicle, the work vehicle being arranged to receive a first control signal from a wireless remote control unit, the first control signal being arranged to control a drive operation of the work vehicle, wherein the safety system comprises a vehicle unit arranged at the work vehicle and an operator unit arranged at the wireless remote control unit, the work vehicle further comprising an ultra-wideband, UWB, transceiver arranged to transmit and receive signals comprising a unique ID and a time stamp, wherein the method comprises the steps of:
- obtaining information relating to a first position of the work vehicle, the information relating to a first position of the work vehicle comprising a first time stamp of an initial time;
- transmitting, at the initial time, at least one signal carrying information relevant for positioning of the wireless remote control unit to the vehicle unit, the information relevant for positioning comprising a first unique ID and the first time stamp;
- determining, based on the first unique ID and using two-way ranging time of flight, a spatial relationship between the work vehicle and the wireless remote control unit based on the information relating to a first position of the work vehicle and the information relevant for positioning of the wireless remote control unit, wherein the two-way ranging time of flight is based on the first time stamp and a second time stamp at a finishing time of the two-way ranging;
- periodically determining if the spatial relationship meets a predetermined criterion;
- and
- providing a second control signal to the work vehicle, the second control signal being arranged to control the drive operation of the work vehicle based on the periodic determination.
Dependencies are inferred from the claim text.