System and method for gauging safe towing parameters

A system for determining the tongue weight of a towed vehicle, the system comprising:

• A) a transducer body with a first end portion for connection to the towed vehicle and a second end portion for connection to a towing vehicle, the transducer body having:
• i) a coupling section adapted located at the first end portion for connection to a hitch ball for coupling in turn with a trailer tongue of the towed vehicle;
• ii) a mounting section being adapted for receipt into a receiver hitch of a towing vehicle;
• and
• iii) an intermediate sensing section located between the coupling section and the mounting section, the intermediate sensing section including:
• a) first and second compartments formed in opposite sides of the transducer body to form a measurement wall with a first thickness;
• b) first and second sensor areas formed as respective first and second depressions in opposite sides of the measurement wall in the first and second compartments, respectively, the measurement wall having first and second sensor surfaces within the first and second depressions, respectively, with a second thickness between the first and second sensor surfaces at the sensor areas being less than the first thickness;
• and
• c) at least one strain sensor located in at least one of the first and second senor areas and connected to one of the first and second sensor surfaces for sensing a load applied to the coupling section;
• and
• B) a display for displaying information related to the tongue weight of a towed vehicle based on the transmitted data.

A receiver hitch system comprising:

• a crossbar;
• a mounting bracket connected at opposite ends of the crossbar for connecting the receiver hitch to a tow vehicle;
• a receiver tube extending rearwardly from the crossbar, the receiver tube being adapted for connection to a drawbar to thereby couple a trailer to the tow vehicle;
• a first surface anomaly associated with at least one of the crossbar, mounting bracket, and receiver tube;
• a first strain sensor operably associated with the receiver hitch and connected to the first surface anomaly for measuring at least one of a trailer tongue weight and trailer pull force;
• and
• a processor operably connected to the first strain sensor for calculating the at least one trailer tongue weight and trailer pull force as a function of strain measured at the first surface anomaly.

A receiver hitch system comprising:

• a crossbar;
• a mounting bracket connected to the crossbar for connecting the receiver hitch to a tow vehicle;
• a receiver tube extending rearwardly from the crossbar, the receiver tube being adapted for connection to a drawbar to thereby couple a trailer to the tow vehicle;
• a first strain sensor operably associated with the receiver hitch for measuring the trailer tongue weight;
• a second strain sensor operably associated with the receiver hitch for measuring the trailer pull force;
• a processor operably connected to the first and second strain sensors for calculating the trailer tongue weight and trailer pull force, respectively;
• and an accelerometer operably associated with the processor for determining an acceleration of the tow vehicle.

A modular strain sensor assembly comprising:

• a sensor mounting plate have a first face and a second face located on an opposite side of the sensor mounting plate;
• a first recessed sensor area formed in the first face;
• a second recessed sensor area formed in the second face opposite the first recessed sensor area to thereby create a center web therebetween;
• a first strain gauge fixedly secured to the center web in the first recessed sensor area;
• a second strain gauge fixedly secured to the center web in the second recessed sensor area;
• wherein a first thickness between the first and second faces is greater than a second thickness of the center web such that shear stresses on the center web is greater than shear stresses on the first and second faces when a load is applied to the modular strain sensor assembly.

A method for determining a safe towing condition of a trailer with respect to a predetermined tow rating of a tow vehicle, the method comprising:

• connecting a trailer hitch between a tongue of the trailer and the tow vehicle;
• operably associating a sensing system with at least one of the trailer hitch, the trailer tongue, and the vehicle, the sensing system being adapted for measuring the tongue weight, trailer weight, and pull forces of the trailer during pulling and being operably associated with a user interface for at least visibly or audibly indicating a safe or unsafe towing condition;
• determining a tongue weight of the trailer with the sensing system;
• determining if the tongue weight of the trailer exceeds a predetermined limit;
• indicating an unsafe towing condition when the tongue weight of the trailer has exceeded the predetermined limit to thereby allow an operator to adjust a load associated with the trailer;
• indicating a safe towing condition when the tongue weight of the trailer is at or below the predetermined limit;
• pulling the trailer with the tow vehicle;
• measuring acceleration and pull forces of the trailer with the sensing system during pulling;
• determining the weight of the trailer by dividing the pull force by the acceleration multiplying the quotient by a gravitational acceleration;
• and
• indicating an unsafe towing condition if the weight of the trailer exceeds a predetermined level.

A method for determining a safe condition of a trailer with respect to a predetermined tow rating of a tow vehicle, the method comprising:

• determining a tongue weight of the trailer;
• pulling the trailer with the tow vehicle;
• measuring acceleration and pull forces of the trailer during pulling;
• determining the weight of the trailer by dividing the pull force by the acceleration multiplying the quotient by a gravitational acceleration
• monitoring the pull forces during trailer towing;
• calculating an average drag coefficient based on the pull forces at constant velocity;
• and
• signaling when a new drag coefficient is greater than a predetermined change in the average drag coefficient.