MICO Inc. has announced the release of the company's first Full Power Hydraulic Brake System with ABS (HABS). The system is designed to provide shorter stopping distance with improved vehicle stability and control during aggressive braking situations, according to the North Mankato, Minn., company. It is designed to accommodate as many as eight control channels and is targeted toward a wide range of mobile equipment applications, including off-road machinery in construction, utility ag and material handling, as well as military applications such as armored personnel carriers (APC) and general purpose vehicles.

The HABS system incorporates a full power brake system that consists of brakes, a tandem modulating pedal valve, an accumulator charging system and dual accumulators.

The pedal-actuated tandem modulating valve produces normal and emergency power-off braking and isolates the front and rear brakes by providing two individual outputs. An electronic control unit monitors wheel speeds and determines the level of braking needed at each wheel to improve vehicle control. It controls the electrohydraulic ABS valves, which are normally open to allow the tandem modulating valve to control brake pressure. As it detects wheel slip, the electronic control unit sends PWM signals to the valves. When current from the control unit is received, pressure from the tandem modulating valve to the brake is blocked, while pressure at the brake is reduced in proportion to the PWM current and the pressure from the tandem modulating valve.

Speed sensors--Hall effect or variable reluctance sensors--are positioned at each wheel and electrical pulses, at a frequency proportional to wheel speed, are sent to the electronic control unit. In addition, the electronic control unit receives pressure information from two pressure transducers that sense pressure at each brake port of the tandem modulating valve. Those proportional signals are used by the control algorithms and as part of diagnostic routines.

In addition to the basic components, additional inputs and outputs can be added to the system, the company said. For example, keyed power or ABS on/off switch signals are typical and outputs to drive stop lamps, low-traction and brake-warning indicator lights can be added. Other inputs and outputs can be custom designed as required, including CAN communications based on SAE J1939, ISO 11783 or other protocols.