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SP1 - SAFEPROBE. Scenario Analysis. Paolo Cravini Piaggio & C. S.p.A(Italy), paolo.cravini@piaggio.com SP1 & SP4 Partner. PTW falling on the roadway PTW falls down on a section of a single/dual carriageway and stay motionless on the road surface. V A. V B = 0. S 0.
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SP1 - SAFEPROBE Scenario Analysis Paolo Cravini Piaggio & C. S.p.A(Italy), paolo.cravini@piaggio.com SP1 & SP4 Partner
PTW falling on the roadway PTW falls down on a section of a single/dual carriageway and stay motionless on the road surface VA VB = 0 S0 Scenario AnalysisUC 7
PTW falling on the roadway PTW falls down on a section of a single/dual carriageway and stay motionless on the road surface Scenario AnalysisUC 7 • Vehicle A – SAFEPROBE Vehicle - Receiver • Safespot platform • Vehicle B – PTW - Transmitter • Speed sensor • GPS • Tilt sensor
PTW overtaking OV while OV making a turn Vehicle B suddenly changes lane on the trajectory of the incoming vehicle A (PTW) S0 VA VB Scenario AnalysisUC 8
PTW overtaking OV while OV making a turn Vehicle B suddenly changes lane on the trajectory of the incoming vehicle A (PTW) Scenario AnalysisUC 8 • Vehicle A – PTW - Transmitter • Speed sensor • GPS • Vehicle B – SAFEPROBE Vehicle - Receiver • Safespot platform
: start speed of vehicle A and B : start relative distance between vehicles (t=0) : limit value of mean deceleration (PTW is roughly 8 m/sec2) S0 VA VB Scenario AnalysisCalculation Safety Margin Concept Data
Vehicle B proceeds with Vehicle A starts to decelerate at Only the case is considered S0 VA VB Scenario AnalysisCalculation Safety Margin Concept Assumptions (after starting manoeuvre)
Approximate stop distance : Where is the typical reaction time S0 VA VB Scenario AnalysisCalculation Safety Margin Concept Definitions
Decelerate motion of vehicle A : Motion at constant speed (vehicle B) : Relative distance between the vehicle (after braking) Scenario AnalysisCalculation Safety Margin Concept Equations of motion Before braking After braking
To avoid collision must assumes always positive values Scenario AnalysisCalculation Safety Margin Concept Equations of motion That is the time corresponding to the minimum relative distance
S0 VA VB Scenario AnalysisCalculation Safety Margin Concept Equations of motion
Scenario AnalysisCalculation Safety Margin Concept Adimensional parameter • If start distance is equal to stop distance • If vehicles are travelling at the same speed • If deceleration is equal than the limit value
S0 VA VB Scenario AnalysisCalculation Safety Margin Concept Equations of motion in terms of
Which is the minimum value for for deceleration of vehicle A in order to avoid collision with vehicle B ? This is expressed by the following condition S0 VA VB Scenario AnalysisCalculation Safety Margin Concept and by setting
Which is the minimum value for for deceleration of vehicle A in order to avoid collision with vehicle B ? This is expressed by the following condition S0 VA VB Scenario AnalysisCalculation Safety Margin Concept
Previous equation gives as output the minimum value of deceleration to avoid collision between vehicles. It is function of 5 parameters that can be monitored by the SAFESPOT system Scenario AnalysisCalculation Safety Margin Concept
The information could be transmitted to the driver of vehicle B in terms of drivingconditions Scenario AnalysisCalculation Safety Margin Concept COMFORT SAFETY CRITICAL
Scenario AnalysisCalculation Safety Margin Concept
Data : Start speed of vehicle A : VA = 10 m/sec Start speed of vehicle B : VB = 6 m/sec Relative distance between vehicles (t=0) : S0 = 20 m Limit value of mean deceleration (PTW is roughly 8 m/sec2) : aLIM PTW deceleration : aR = 6 m/sec2 Reaction time : τ= 1 sec Scenario AnalysisCalculation Example – User Case 8 – Comfort Situation
Results : Stop distance vehicle A : ST= 16.25 m Delta ST= 14.66 m – minimum relative distance Time corresponding to minimum relative distance : t*= 1.66 sec Relative distance between vehicles (t=0) : S0 = 20 m Kmin = 0.06 (Comfort Situation) The minimum relative distance is the space between the vehicle at the end of the manoeuvre Scenario AnalysisCalculation Example – User Case 8 – Comfort Situation
Data : The real situation (car turning in front of the PTW) could be analysed by considering the car speed at the turning point equal to zero Start speed of vehicle A : VA= 10 m/sec (previous comfort situation) Start speed of vehicle B : VB = 0 m/sec (new situation) Relative distance between vehicles (t=0) : S0 = 20 m Limit value of mean deceleration (PTW is roughly 8 m/sec2) : aLIM PTW deceleration : aR = 6 m/sec2 Reaction time : τ= 1 sec Scenario AnalysisCalculation Example – User Case 8 – Safety Situation
Results : Stop distance vehicle A : ST= 16.25 m Delta ST= 1.66 m – minimum relative distance Time corresponding to minimum relative distance : t*= 2.66 sec Relative distance between vehicles (t=0) : S0 = 20 m Kmin = 0.625 (Safety Situation) – The safety margin decrease due to VB = 0 The minimum relative distance is the space between the vehicle at the end of the manoeuvre Scenario AnalysisCalculation Example – User Case 8 – Safety Situation
Data : Start speed of vehicle A : VA = 11 m/sec(new situation) Start speed of vehicle B : VB = 0 m/sec(previous safety situation) Relative distance between vehicles (t=0) : S0 = 20 m Limit value of mean deceleration (PTW is roughly 8 m/sec2) : aLIM PTW deceleration : aR = 6 m/sec2 Reaction time : τ= 1 sec Scenario AnalysisCalculation Example – User Case 8 – Critical Situation
Results : Stop distance vehicle A : ST= 23.56 m Delta ST= -1.08 m (crash event) Time corresponding to minimum relative distance : t*= 2.83 sec Relative distance between vehicles (t=0) : S0 = 20 m Kmin = 0.84 (Critical Situation) Scenario AnalysisCalculation Example – User Case 8 – Critical Situation