| Brake-by-Wire System (See Figure 1) These systems provide the flexibility of control while complying with the primary and secondary braking requirements of several braking standards. Dual pedal angle sensors send signals to the primary brake-by-wire controller and a dual input valve driver. The primary brake-by-wire controller is programmed to provide all the needs of the brake system including current output to an electrohydraulic modulating brake valve (EBV) and a second command signal to the dual input valve driver. The dual input valve driver sends a current to a second EBV proportional to the larger of the two input command signals. Features of this type of system include: • Ability for designers to remove the brake valve and the hydraulic hoses from the operator station • Provides primary and secondary braking to meet industry standards • Pedal force feedback is proportional to pedal angle • Programmable pressure vs. pedal angle functions • Easy to add additional remote operator stations • Automated braking can be programmed to occur based on inputs from other sensors or controllers • Operator warning and vehicle stop light control • Fault diagnostics for easy troubleshooting Electronically Enhanced Full Power brake System (See Figure 2) The addition of electrohydraulic to enhance the full power system allows designers to add control flexibility to the brake system while maintaining the hydro-mechanical reliability and redundancy of the pilot operated tandem modulating valve. The pedal angle sensor, electronic control unit and electrohydraulic modulating brake valve (EBV) are used to provide programmable pressure vs. pedal angle function to the brake system. The output of the EBV is connected to the pilot of the tandem modulating valve. This pilot pressure acts on the pilot piston to provide force feedback to the operator and the tandem spools of the modulating valve to provide redundant pressure modulation to the brakes. Features of this type of system include: • Provides primary and secondary braking to meet industry standards • Programmable force vs. pedal angle functions • Brake pressure proportional to pedal force • Easy to add additional remote operator stations • Automated braking can be programmed to occur based on inputs from other sensors or controllers • Brake system continues to operate with the mechanical input to the pilot operated tandem modulating valve should an electronic fault occur • Operator warning and vehicle stop light control • Fault diagnostics for easy troubleshooting 4 |