Showing papers on "Drive by wire published in 2008"

Offline Parameter Estimation of Permanent Magnet Sychronous Machines by means of LS Optimization

Abstract: Industrial applications, especially automotive ones should be robust and cheap. Both properties can be improved by using model based state estimation. Sensor cost can be reduced if some signal values are calculated from the other, already measured signals or the robustness of the system can be increased by supervising the sensors by calculating their measurement value out of the existing signal values. Robustness and redundancy is extremely important considering drive-by-wire technology, where the physical connection between the steering wheel and the wheels of the vehicle is omitted. This paper reports advances in permanent magnet synchronous machine model identification. By measuring machine input voltages, output currents speed and using the least squares optimization method, internal parameters of the machine can be estimated. In the identification stage, the model excitation signals are the current values and the speed of the machine and the response signals are the input voltages. After having a properly identified model, the output currents and electrical torque of the machine can be calculated knowing the input voltages and the speed of the machine. Those current sensors can be either eliminated or supervised by the model based redundant information.

Failure mode effects mitigation in drive-by-wire systems

Abstract: Systems and methods for mitigating failure mode effects in a steer-by-wire system. The system includes a controller configured to alter a direction of the vehicle when the controller is in a failure mode. A steering device is coupled to a detector. The detector is configured to detect a steering input from a driver and output a signal representative of the steering input. A first actuator is coupled to a first control device. The first control device is configured to generate a first control signal representative of the steering input when the controller is in the failure mode. The first actuator alters the direction of the vehicle by removing energy from the vehicle. A second actuator is coupled to a second control device. The second control device is configured to generate a second control signal representative of the steering input when the controller is in the failure mode. The second actuator alters the direction of the vehicle by adding energy to the vehicle.

Design and Testing of a Dual-Path Front Hydrostatic Drive-By-Wire Control System for an Off-Road Vehicle

Abstract: This article discusses the design, implementation, and testing of a dual-path front hydrostatic drive wheel, rear caster wheel off-road vehicle. A mathematical model of the engine and major machine components was used to simulate vehicle behavior and design a drive-by-wire control system for stability and turning. The drive-by-wire system was implemented on the machine, and the model and controller were experimentally verified through testing. The physical system model contains a simplified diesel engine, hydraulic pumps and motors, gearboxes, wheels, and associated interconnecting components. The diesel engine was coupled to two hydraulic pumps via a gear box, with each hydraulic pump independently supplying flow to each hydraulic wheel motor. External disturbances were applied to the contact patch of each drive wheel. The force on each wheel was determined independently and combined to simulate vehicle acceleration, rotation, or both. A model-based controller was designed for and implemented on the machine. In the simulation, the control algorithm used steering input, speed input, and yaw rate to control pump displacement for each wheel. The controller adjusted ground drive pump displacements to maintain directional (yaw) stability when a disturbance was applied to either wheel. The controller algorithm was also implemented and verified on a test vehicle by removing the existing mechanical linkages previously used to control the hydraulic pump displacements and retrofitting electrohydraulic pump control. A joystick replaced the steering wheel and propulsion lever and was used to provide the driver inputs to the electronic controller. Testing the vehicle demonstrated positive results with stable operation up to 20 km/h (12 mph).

Drive-by-wire steering system experimental device

Abstract: Disclosed is a wire-transmission steering system test device which comprises a wire-transmission steering system and is characterized in that the device also comprises a vehicle speed signal generator, a quality signal generator, a first steering gear loading device, a second steering gear loading device, a first pressure sensor, a second pressure sensor and a data acquisition device; the output ends of the vehicle speed signal generator and the quality signal generator are respectively connected with the speed signal input end and the quality signal input end of the ECU; one end of a gear rack is connected with the first steering gear loading device through the first pressure sensor; the other end of the rack gear is connected with the second steering gear loading device through the second pressure sensor; the signal output ends of the first pressure sensor and the second pressure sensor are respectively connected with the first and the second pressure signal input ends of the data acquisition device; the wire-transmission steering system test device can simulate various conditions during the driving process of the vehicle and obtain the parameters and the relations among the parameters under different driving situations

Drive by wire contactless throttle control apparatus

Abstract: A drive by wire contactless throttle control which includes a contactless Hall-effect magnetic sensor. The Hall-effect magnetic sensor can be located in a mounting bracket in contactless association with a thumb lever on a handle bar. A magnet can be placed in a slot inside the thumb lever with a bonder and filled with an epoxy. The Hall-effect magnetic sensor senses the magnetic field produced by the magnet as the thumb lever rotates and determines position of the thumb lever and generates a signal based on the sensed position. The signal can be sent to an ECU (Electronic Control Unit) utilizing electrical wires in the form of varying voltage, which in turn controls throttle of a vehicle, such as an all terrain vehicle, snowmobile, etc.

Robust Optical Sensors for Safety Critical Automotive Applications

Abstract: Optical sensors for the automotive industry need to be robust, high performing and low cost. This paper focuses on the impact of automotive requirements on optical sensor design and packaging. Main strategies to lower optical sensor entry barriers in the automotive market include: Perform sensor calibration and tuning by the sensor manufacturer, sensor test modes on chip to guarantee functional integrity at operation, and package technology is key. As a conclusion, optical sensor applications are growing in automotive. Optical sensor robustness matured to the level of safety critical applications like Electrical Power Assisted Steering (EPAS) and Drive-by-Wire by optical linear arrays based systems and Automated Cruise Control (ACC), Lane Change Assist and Driver Classification/Smart Airbag Deployment by camera imagers based systems.

Travelling limit apparatus for drive by wire system and travelling limit method of a car using the same

Abstract: A traveling limit apparatus of a drive by wire system and a traveling limit method of a vehicle using the same are provided to prevent the vehicle from traveling by shifting to a traveling limit mode when sensors detect car theft and drunken driving A traveling limit apparatus of a drive by wire system comprises sensors(100), a signal processing control unit(110), and a wheel control unit(130) The sensors detect that a vehicle is stolen or that a drunken driver is behind a wheel and outputs alarming signals Once the alarming signals are output the signal processing control unit shifts a drive mode into a traveling limit mode, and outputs specific signals The wheel control unit actuates a drive device such as a motor according to the signal output by the control units and controls wheels, brakes, a transmission, and a throttle In the traveling limit mode, the wheel control unit receives fixed steering wheel information, and the signal processing control unit keeps the wheels stopped